How to build Switching Regulator Circuit Diagram operating at 200Khz

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Build a Switching Regulator Circuit Diagram operating at 200Khz. This Switching Regulator Circuit Diagram provides a regulated dc with less than 100 mV of ripple for microprocessor applications. Necessary operating voltages are taken from the bleeder resistor network connected across the unregulated 28 V supply. 



Switching Regulator Circuit Diagram

The output of the LM710 comparator (actually an oscillator running at 200 kHz) is fed through a leveNshifting circuit to the base of bipolar transistor Q2 This transistor is part of a bootstrap circuit necessary to turn the power MOSFET full on in totem-pole MOSFET arrays.
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Simple Isolated Converter Circuit Diagram

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This the Simple Isolated Converter Circuit Diagram. In this Simple Isolated Converter Circuit Diagram a negative output voltage de-de converter generates a -5 V output at pin A. In order to generate -5 Vat point A, the primary of the transformer must fly back to a diode drop more negative than -5 V. If the transformer has a tightly coupled 1/1 turns ratio, there will be a 5 V plus a diode drop across the secondary. 

The 1N5817 rectifies this secondary voltage to generate an isolated 5-V output. The isolated output is not fully regulated since only the -5 V at point A is sensed by the MAX635.



Simple Isolated Converter Circuit Diagram

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Build a Portable Nicad Battery Charger Circuit Diagram

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This is a Portable Nicad Battery Charger Circuit Diagram. This circuit can you build easily, The portable charger is intended primarily to give model enthusiasts the opportunity of charging their Nicad batteries from a car battery out in the open. The supply voltage for the circuit is regulated by IC1. When the circuit is connected to the car battery, D2 lights only if the Nicad to be charged has been connected with correct polarity. For that purpose, the + terminal of the Nicad battery is connected to the base of T1 via R8. Because even a discharged battery provides some voltage, T1 is switched on and D2 lights. 



Portable Nicad Battery Charger Circuit Diagram

Only if the polarity is correct will the pressing of the start switch, SI, have any effect. If so, the collector voltage of T1 is virtually zero so that monostable IC2 is triggered by SI. The output, pin 3, of this CMOS timer then becomes high, T2 is switched on and relay Rel is energized. Charging of the Nicad battery, via R5 and D6, then begins and charging indicator D4 lights. During the charging, C4 is charged slowly via PI and R4. The value of these components determines the mono time of IC2 and thus the charging period of the Nicad battery. With values as shown in the diagram, that period can be set with PI to between 26 and 33 min. Notice that this time is affected by the leakage current of C4; use a good-quality capacitor here. 

The charging can be interrupted with reset switch S2. The charging current through the Nicad battery is determined by the value of R, which can be calculated: Ic is the charging current, which is here because the chosen charging period is twice the nominal value of the capacity of the Nicad battery. Resistor R must be able to dissipate a power of 1/ R W. Finally, make sure that the Nicad battery is suitable for fast charging; never charge for longer than half an hour! 
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Build a Uninterpretable Supply Circuit Diagram

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How to Build a Uninterpretable Supply Circuit Diagram. This Uninterpretable Supply Circuit Diagram provides a continuous supply of regulated + 5 V, with automatic switch-over between line power and battery backup. When the line-powered input voltage is a + 5 V, it provides 4A V to the MAX630 and trickle charges the battery, If the line-powered input falls below the battery voltage, the 3.6 V battery supplies power to the MAX630, which boosts the battery voltage up to +5 V, thus maintaining a continuous supply to the uninterpretable +5 V bus. Since the +5 V output is always supplied through the MAX630, there are no power spikes or glitches during power transfer. 



Uninterpretable Supply Circuit Diagram

The MAX630`s low-battery detector monitors the line-powered + 5 V, and -the LBD output can be used to shut down unnecessary sections of the system during power failures. Alternatively, the low-battery detector could monitor the NiCad battery voltage and provide warning of power loss when the battery is nearly discharged. Unlike battery backup systems that use 9-V batteries, this circuit does not need +12 or +15 V to recharge the battery, Consequently, it can be used to provide + 5 V backup on modules or circuit cards which only have 5 V available.
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Fifty Percent Wave Rectifier Circuit Diagram

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This is a simple Fifty Percent Wave Rectifier Circuit Diagram. This Fifty Percent Wave Rectifier Circuit Diagram provides for accurate half wave rectification of the incoming signal. For positive signals, the gain is 0; for negative signals, the gain is — 1

By reversing both diodes, the polarity can be inverted. This circuit provides an accurate output, but the output impedance differs for the two input polarities and buffering may be needed. The output must slew through two diode drops when the input polarity reverses. The NE5535 device will work up to 10 kHz with less ttan 5% distortion.


Fifty Percent Wave Rectifier Circuit Diagram

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How to Build a Battery Charging Regulator Circuit Diagram

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Build a Battery Charging Regulator Circuit Diagram. The Battery Charging Regulator Circuit Diagram is capable of charging a 12 volt component selection. When the battery voltage battery at up to a six ampere rate. Other volt- reaches its fully charged level, the charging ages and currents, from 6 to 600 volts and up to SCR shuts off, and a trickle charge as deter-300 amperes, can be accommodated by suitable mined by the value of R4 continues to flow.


Simple Battery Charging Regulator Circuit Diagram

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Semi Low Power Inverter Circuit Diagram

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This Semi Low Power Inverter Circuit Diagram uses only 9 parts and turns 10 to 16 Vdc into 60-Hz, 115-V square-wave power to operate ac equipment up to 25 W. The first section of the 556 timer chip is wired as an stable oscillator with R2 and C1 setting the frequency. The output is available at pin 5. The second section is wired as a phase inverter. 


Semi Low Power Inverter Circuit Diagram

That output is available at pin 9. Resistors R3 and R4 keep output transistors Q1 and Q2 from loading down the oscillator. The two transistors drive the transformer push-pull fashion. When one transistor is biased-on, the other is cut-off. The transformer is a 120 V/18 VCT unit that is connected backwards, so that it steps the voltage up rather than down. Oscillator circuit U1, R1, R2, and C1 operates from about 4 to 16 V with a very ~stable output.


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Build a +15V 1 a Regulated Power Supply Circuit Diagram

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Build a +15V 1 a Regulated Power Supply Circuit Diagram. This is a simple +15-V-1-a-regulated-power-supply circuit diagram. The supply receives + 20 Vdc from the rectifier/filter section. This is applied to pins 11 and 12 of the uA723, as well as to the collector of the 2N3055 series-pass transistor. The output voltage is sampled through R1 and R2, providing about 7 V with respect to ground at pin 4. 


+15V 1 a Regulated Power Supply Circuit Diagram


The reference terminal at pin 6 is tied directly to pin 5, the non inverting input of the error amplifier. For fine trimming the output voltage, a potentiometer can be installed between R1 and R2. A 100-pF capacitor from pin 13 to pin 4 furnishes gain compensation for the amplifier. Base drive to the 2N3055 pass transistors furnished by pin 10 of the uA 723. Since the desired output of the supply is 1 A. maximum current limit is set to 1.5 A by resistor Rsc whose value is 0.433 0. A 100-J
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Simple Voltage Multiplier Circuit Diagram

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This is a Simple Voltage Multiplier Circuit Diagram. This Simple Voltage Multiplier Circuit Diagram we build to day. how to build lets start. Figure 99-l(a)`s circuit exhibits a high-output impedance as a result of the small effective capacitance of the series-connected capacitors, and it exhibits considerable voltage loss due to all of the diode drops. Further, this circuit requires 2 diodes and 2 capacitors to produce a dc output voltage approximately times the rail voltage. Figure 99-1 (b)`s circuit multiplies more effectively using fewer diodes and capacitors. 


Simple Voltage Multiplier Circuit Diagram


The parallel arrangement of the capacitors lets you use smaller capacitors than those required in Fig. 99-1(a). Alternatively, when using the same capacitor values of Fig. 99-1 (a), the output impedance will be lower. Whereas the clock source directly drives only one of the two strings of capacitors in Fig. 99-1(a), Fig. 99-l(b)`s clock drives both strings with opposite phases. 

This drive scheme doubles the voltage per stage of two diodes. A final diode is necessary to pick off the dc output voltage because both strings of capacitors now carry the - p ac input-voltage waveform. The ICL7667 dual-FET driver accepts a TTL drive swing and provides a low-impedance push-pull drive to the diode string. This low impedance is particularly helpful when using a long string to raise output voltage to more than 100 V, starting from a low rail voltage.  
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Simple 50-W Electronic Amplifier Circuit Diagram

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This electronic amplifier project is an IC amplifier module from ST Microelectronics, the TDA7294. It is intended for use as a top quality audio class AB amplifier in hi-fi applications. It's low noise and distortion, wide bandwidth and nice output current capability, enabling it to supply high power in to both four ohm and 8 ohm lots. It's both short circuit and thermal protection.

With the addition of a handful of parts and an appropriate power supply, this module will deliver over 50W RMS in to four or 8 ohms-with < 0.1% Total Harmonic Distortion (THD) and < 0.1% Inter-modulation Distortion (IMD). It is also suitable as a replacement power amp stage, or upgrade for plenty of existing amplifiers of between 30W-50W, provided they have an appropriate dual supply, & most do.

The Specifications of the electronic amplifier project there are:

D.C. Input : 35V
Output power : > 50W RMS, 4-8 ohm load.
Gain : 24 dB (30dB modification)
Input sensitivity : one.3V for 50W, 8 ohm
Signal-to-Noise ratio : > 95 dB, (>105 dBA)
Frequency response : approx. 20Hz - 200kHz, �3 dB
Slew rate : > 10V/uS
THD : < 0.01%, 1W-40W, 1kHz
IMD : < 0.01%, 1W

The maximum supply voltage of the IC is +/- 40V. However the maximum dissipation of the IC can be exceeded even at a lower voltage. Therefore the supply voltage used require not be over +/- 35V. This can be constructed using a 50V middle tapped-transformer, a diode bridge rated at 5A (min.) & a pair of electrolytic capacitors, as shown below. A lower secondary voltage transformer could even be used but the reduced DC voltage will lead to less power output in to 8 ohms. You can still receive 50W in to four ohms with only 24V supply rails.

A 36V C.T. transformer will give you approx +/- 25V rails. The-mains transformer used ought to be rated at a maximum of 80VA. In the event you require to run modules in a stereo amplifier you can use a common power supply. In this case the transformer ought to be rated at 150VA or greater.

Electronic Amplifier Circuit Diagram Description

Most of the circuitry is contained within the IC module. The input signal is applied to pin three by capacitor C1 & low-pass filter R1/C2. The filter improves the pulse response & helps cease RF signals. The lower -3dB point is determined-by R2/C1 & R4/C3. This is about 20Hz for the values used. The upper -3dB point is over 200kHz. C7/C8 & C9/C10 provide additional power supply filtering or decoupling.

Simple 50-W Electronic Amplifier Circuit Diagram

 

R3/R4 are the feedback resistors. The gain is 1+R3/R4 which is approx 16 times, or 24dB. In case you need to increase the input sensitivity you may alter the resistors to suit. Changing R3 to 22k would increase the gain to 30dB and lower the input-required for 50W in to 8 ohm, to 0.6V, without affecting performance much. In case you reduce the worth of R4 you will also need to increase C3 to maintain bass response, as this sets the feedback low frequency roll off.

Pin ten is a mute input and pin 9 provides a standby mode. Muting ought to always happen before standby mode is selected. Connecting these pins permanently to the supply rail ensures that the amplifier comes on immediately on power up. Any switch-on clicks may be eliminated by increasing the time constants of R5/C4 and R6/C5 if necessary.

Make definite that a heavy duty heat-sink rated at least one.4 degree C/W or better is used.

Simple 50-W Electronic Amplifier Circuit Diagram

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Sub-Woofer and Controller Circuit Diagram

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Sub woofers are popular, with home theater being of the driving forces. However, a nice sub adds considerably to normal hi-fi program material, & so if it is predictable & has nice response characteristics.

 all of sub woofers use a immense speaker driver in a immense box, with tuning vents & all the difficulties (& vagaries) that conventional operation entails. By conventional, I mean that the speaker & cabinet are operated as a resonant technique, using the Thistle-Small parameters to get a box which will (if everything works as it ought to) provide excellent performance.

Completed Prototype


Completed Prototype

A fast word is warranted here, to let you decide if the speaker you have will actually work in a little sealed enclosure. The EAS principle will permit any driver to extend to twenty Hz or even lower. A lovely fast check is to stick the speaker in a box, and drive it to 100W or so at twenty Hz - you ought to see lots of cone movement, a few things will rattle, but you should not actually listen to a tone. A "bad" speaker will generate 60 Hz (third harmonic) - in the event you don't listen to anything, the speaker will work in an equalized sub.

If a tone is audible, or the speaker shows any signs of distress (such as the cone breaking up with appropriate terrible noises), then the driver cannot be used in this manner. Either discover a different driver, or use a vented enclosure.

Before you can build your own EAS box, you will require to pick an appropriate driver, using the above as a guide. Cone tour will be high at the lowest frequencies, so the speaker needs to be able to high power, lovely tour, & of reasonable size (there is no substitute for cone area for moving air at low frequencies). I am using a 380mm (15") driver, but smaller drivers (say 300mm - 12") can be used, or even a bigger number of smaller drivers. I have also had excellent results with a single 300mm driver, which has lower sensitivity (as would expect) but is perfectly adequate for normal usage.


The check methods I used are applicable to any combination, but in general I recommend either a single giant driver or a pair of (say) 300mm units. The next hurdle is the amplifier needed to drive the speaker. This is not trivial. If the selected driver has a sensitivity of 93dB / W @ one metre, then you can safely assume that the efficiency will be less than this below resonance, by a factor of possibly 6dB or more. In case you are used to driving a sub with 100W, this means that you have increased the power to 400W - although this is an over-simplification.

If they are to operate the sub from 60Hz (my aim from the outset), they will increase the power by 12dB for each octave, so if 20W is necessary at 60Hz, then at 30Hz this has increased to 320W, & at 15Hz, you will require over 5kW.

Fortunately, the reality is a tiny different, & 400W or so will be over sufficient for a powerful process, due chiefly to the fact that the energy content in the low bass region is not normally all that great. (Although some program material may have high energy content, in general this is not the case). The EAS process augments the existing process, which is allowed to roll off naturally - contrast this with the normal case, where a crossover is used to separate the low bass from the main process, so existing speaker capability is lost.

The box I built is made from 25mm (1") MDF (Medium Density Fiberboard), & filled with fiberglass. Apart from the fact that it is very heavy (which is a lovely thing, because it desires to walk with low frequencies), the cabinet is acoustically dead, with no resonances in the low frequencies at all ( unlike my house & furniture, dammit !). The woofer is recessed in to the baffle, & sealed with weather sealing foam. When attaching the speaker, do NOT use wood screws, or any other screw in to the MDF. I used "Tee" nuts. I have no idea what they are called elsewhere in the world, but they look like this

TEE NUT

The middle is tapped, and accepts a metal thread screw, and the small spikes mean that you must drill a hole, and hammer in the Tee nut. In case you use a screw through the hole and screwed lightly in to the Tee nut, you can hold it in place as you bash away at it, and can also see that it is straight when you are done. make sure that the finish of the screw doesn't stick out the finish, or you will seldom remove it again after the hammering! I recommend that you lock the tee nut in to place with some construction adhesive (don't get any in the threaded section) so they don't fall out while you are installing the speaker.

The EAS Controller
The controller is (actually very) simple, & the circuit is shown in Figure one. An input buffer ensures that the input impedance of the source does not affect the integrator performance, & allows summing of left & right channels without any crosstalk. The output provides a phase reversal switch, so that the sub can be properly phased to the remainder of the process. If the mid-bass disappears as you advance the level control, then the phase is wrong, so switch to the opposite position.

Figure 1 - The Original EAS Filter / Controller

It turns out that the controller can be simplified, but there is no point. While the dual pot appeared like a lovely suggestion when I built my unit, it actually only changes the gain. Now, having experimented some more, this is an excellent thing, since it means that the level through the controller can be set to make positive that there is no distortion - there can be a immense amount of gain at low frequencies, & if the gain is high, distortion is assured!

The integrators (U1B & U2A) include shelving resistors (R6 & R9), & the capacitor / resistor networks (C1-R4, C3-R7) be positive that signals below 20Hz are attenuated. In case you don't require to go that low, then the worth of the caps (or the resistors R4 & R7) can be reduced. I used four.7uF caps, & these are non-polarized electrolytic - a high value was needed to keep the impedance low to the integrators. I originally included the dual pot (VR1) to permit the upper frequency roll off to be set - however it does no such thing (as described above). The final output level is set with VR2, which may be left out if your power amp has a level control.

It is OK to substitute different op amps, but there is tiny reason to do so. Any substitution tool ought to be a FET input op amp, or DC offset may be an issue. Do not be tempted to make use of a DC coupled amp. If the you are planning to make use of is DC coupled, the input ought to be isolated with a capacitor. Pick a value to give a -3dB frequency of about 10Hz, as this will have tiny effect on the low frequency response, but will help to attenuate the subsonic frequencies.

The unity gain range (using a 20k pot as shown) is from 53Hz to 159Hz. This ought to be sufficient for most systems, but if desired, the resistors (R5 & R8) can be increased in value to 22k, or you can select a bigger value pot. Using 22k resistors & the 20k pot will give a range from 36Hz to 72Hz.

To permit lower frequencies, you can increase the 100k shelving resistors (R6 and R9) to 220k, and increase the high pass capacitors (four.7uF) with 10uF (or R4 & R7 may be increased - a maximum of four.7k is recommended). This will give a turnover frequency of around 8Hz, but expect to make use of much more power, as there will likely be significant sub-sonic energy that will generate huge cone excursions with no audible benefit.

The input must be a standard full range (or for a stampeded method, the whole low frequency signal). Do not use a crossover or other filter before the EAS controller. For final modification, and to integrate the method in to your listening room, I recommend the constant-Q equalizer. The final result using this is extraordinarily nice - I have flat in-room response to 20Hz!

For the power supply, use the in anything else will provide +/-15V at a few Milli amps. My supply is not even regulated, & the whole method is as close to noiseless as you will listen to (or not listen to). Construction is not critical - I built mine on a piece of Overboard (perforated prototype board), & managed to fit everything (including the power supply rectifier & filter) on a piece about 100 x 40 millimeters with room to spare.

The EAS method is surprisingly simple to set up with no instrumentation. Of coursework in case you have an SPL meter & oscillator you can also confirm the settings with measurements. Keep in mind that the room acoustics will play havoc with the results, so unless you require to drag the whole method outside, setting by ear might be the simplest. Even in case you did get it exactly right in an anechoic surroundings, this would alter one time it was in your listening room anyway.

It takes a small experimentation to get right, but is surprisingly simple to do. When properly set, a check track (or bass guitar) ought to be smooth from the highest bass note to the lowest, with no gross peaks or dips. Some are inevitable because of room resonances & the like, but you will discover a setting that sounds "right" with small difficulty.

Performance Of My Prototype
I measured 80dB SPL at one meter in my workshop (sub-woofer perched on a chair in more or less the middle of the space) with at 25Hz & 70W. This improved dramatically when the unit was installed in the listening room, but as I said earlier, there is usually not a lot recorded below around 35Hz. The longest pipe on the organ is usually about 16Hz, but larger pipes still may be used. It was found necessary to cease group of diapasons (able to 8Hz) in the famous Sydney Town Hall organ because when they were used, the very low frequency caused building destroy.

A couple of orchestral recordings revealed traffic (or perhaps underground railway) rumble that I was unaware of before (however this was before it was set correctly, and the bass was a tad louder than needed). One time set up properly, its presence is unobtrusive - except I now have about and a half octaves of additional bottom finish.

I finally decided on a 20Hz maximum frequency (-3dB), and this is reflected in the part values shown in Figure one. The actual roll-over frequency is 16.5Hz, after which the output is attenuated at about 12dB / octave (see Figure two). Without the roll off capacitors, the gain would be 20dB at 20Hz. Unity gain frequencies are about 4Hz and 63Hz with the 20k pot(s) centered.

Figure 2 - Frequency Response of EAS Controller

awesome Australian readers may recognize the woofer brand in the picture (Figure three) of my done unit. The compact size of the box can be seen from the fact that there is tiny spacing around the speaker itself, and most of what is there is the top and sides - I used 25mm MDF, so it makes the outside of the box a bit bigger than the inside. Outside dimensions are 470W x 450H x 410D (18 1/2"W x 17 1/2"H x 16"D), which gives a capacity of 60 liters (about two.1 ft³ - excluding the internal space occupied by the speaker. I think you would agree that this is a small box indeed for a 380mm loudspeaker that performs down to 15Hz.

Figure 3 - Photo of Completed EAS Cabinet


Overall, I would must say that I doubt that any conventional design would be as compact, or would have such clarity & solidarity. Being a sealed box, there is not of the "waffle" that ported designs often give, & the speaker is protected against excessive tour by the air pressure in the box itself (below the cutoff frequency, anyway).

The bottom finish in my technique is now staggering. It is rock solid, & absolutely thunders when called on. The 400W amp is over sufficient for the job, thinking about it's to keep up with a biamped main technique able to high SPL (up to 120dB at my listening position). In fact a fast check indicates that 200W would have been (but \. better to have it & not require it than require it & not have it).

The fact that the EAS design augments the existing speakers than taking over from them with a crossover goes a long way towards ensuring the power requirements do not get out of hand. As an added benefit, I have found that I get the same aural sensation at much lower SPLs - I can listen happily at 90dB, but it sounds much louder. I may even listen to the phone ring while listening now !
All in all, I feel it is unlikely that anything other than an isobaric enclosure could give the same performance for a box size even close to the EAS box,& even then would be limited to about 35Hz. Added to this is the unpredictable combined response of the main speakers and the sub, which is not an Problem with this design. With an EAS system, more power is necessary than a standard design, but for plenty of people, power is less costly than space.
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25-W Audio Power Amplifier Circuit Diagram

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This audio power amplifier project is based on LM1875 amplifier module from National Semiconductor. It can deliver up to 30W of power using an 8 ohm load & dual 30V DC power supplies. It is designed to operate with maximum outside parts with current limit & thermal shutdown protection features . Other features include high gain, quick slew rate, wide power supply range, giant output voltage swing & high current capability.

Summary of the audio amply-fire features:

  • Low distortion: 0.015%, 1 kHz, 20 W
  • Wide power bandwidth: 70 kHz
  • Wide supply range 16V-60V
  • Up to 30 watts output power
  • Internal output protection diodes
  • Protection for AC & DC short circuits to ground
  • 94 dB ripple rejection
  • Plastic power package TO-220
25V Power Supply

The schematic below shows how the +25V DC & -25V DC are obtained. In order to provide power supply for two stereo amplifiers, a power transformer rating of 80VA with 240V/36V middle tapped secondary winding is used. The secondary output of the transformer is rectified by using 1N5401 diodes together with four electrolytic capacitors to smoother the ripple voltage. A fuse & a varistor are connected at the primary input to protect the circuit against power surge.

25-W Audio Power Amplifier Circuit Diagram



Audio Amplifier Module

The +25V & -25V DC power supply are connected to the audio amplifier module through a 2A fuse with the peripheral devices shown in the schematic below. The audio input signal to be amplified is coupled to pin one of LM1875 through the resistor R1 and electrolytic capacitor E5.

The output signal at pin four of LM1875 can be used to directly drive a 8 ohm loudspeaker. Resistor R6 and capacitor C5 prevent-the capacitance developed at the long speaker leads from driving the amplifier in to High Frequency Oscillation.

A heat-sink with a thermal resistance rating of one.4 Cecilius/Watt or better must be used or else the amplifier module will-be cut-off from operation due to the heat that will build up in the coursework of the operation of the amplifier. Take note that the heat sink tab on the IC module is internally connected to the -25V power supply hence it must be isolated from the heat sink by the use of an insulating washer. If this is not done, the negative rail will be shorted to ground.





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Electronic Rf Type Battery Charger Circuit Diagram

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This is a simple Electronic Rf Type Battery Charger Circuit Diagram. This type of charger couples RF from L2 to an external pickup coil. The pickup coil connects to a rectifier and battery to be charged. This idea is handy because no wire or contacts are required. L2 is 10T #24 wire and L3 is 10T #30 wire. Both coils are mounted on a 1 V ferrite rod.

Electronic Rf Type Battery Charger Circuit Diagram


Electronic Rf Type Battery Charger Circuit Diagram



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Build a Efficient Negative Voltage Regulator Circuit Diagram

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How to Build a Efficient Negative Voltage Regulator Circuit Diagram. This simple Efficient Negative Voltage Regulator Circuit Diagram is One v;ay to provide good negative-voltage regulation is with a low-dropout positive-voltage regulator operating from a well-isolated secondary winding of switch-mode circuit transformer. The technique works with any positive-voltage regulator, although highest efficiency occurs with low-dropout types. 

Under all loading conditions, the minimum voltage difference between the regulator ViN and VoUT pins must be at least 1.5 V, the LT1086`s low-dropout voltage. Efficient-negative-voltage-regulator Rating: 7.00/10 (23Votes cast)Category: Power Supply Circuits / AC to DC & DC to DCViews: 3Rank: 5One v;ay to provide good negative-voltage regulation is with a low-dropout positive-voltage regulator operating from a well-isolated secondary winding of switch-mode circuit transformer. 



Efficient Negative Voltage Regulator Circuit Diagram

The technique works with any positive-voltage regulator, although highest efficiency occurs with low-dropout types. Under all loading conditions, the minimum voltage difference between the regulator ViN and VoUT pins must be at least 1.5 V, the LT1086`s low-dropout voltage.Efficient-negative-voltage-regulatorIf this requirement isn`t met, the output falls out of regulation. 1vo programming resistors, R1 and R2, set the output voltage to 12 V, and the LT1086`s servo the voltage between the output and its adjusting (ADJ) terminals to 1.25 V. 

Capacitor C1 improves ripple rejection, and protection diode D1 eliminates common-load problems. Since a secondary winding is galvanically isolated, a regulator`s 12 V output can be referenced to ground. Therefore, in the case of a negative-voltage output, the positive-voltage terminal of the regulator connects to ground, and the -12 V output comes off the anode of Dl. The ViN terminal floats at 1.5 V or more above ground.
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Simple Micro Power Supply Circuit Diagram

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This is simple micro power supply circuit diagram. The circuit uses a CA3440 BiMOS op amp and CA3086 transistor array. The no-load current from 5-volt supply is 1.5 µ A. Load current can go as high as 200 µ and still maintain output voltage regulation within 0.05%.

 Micro Power Supply Circuit Diagram

Simple Micro Power Supply Circuit Diagram

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Build a Low Ripple Power Supply Circuit Diagram

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How to build a low ripple power supply circuit diagram. This simple low ripple power supply circuit diagram may be used where a high current is required with a low ripple voltage (such as in a high powered class AB amplifier when high quality reproduction is necessary) , Ql, Q2, and R2 may be regarded as a power darlington transistor.

ZDl and Rl provide a reference voltage at the base of Ql. ZDl should be chosen thus: ZDl = Von-1. C2 can be chosen for the degree of smoothness as its value is effectively multiplied by the combined gains of Q1/Q2, if 100 µF is chosen for C2, assuming minimum hfe for Ql and Q2, C = 100 x 15(Q1) x 25(Q2) = 37,000 µf.



Low Ripple Power Supply Circuit Diagram

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Build a Programmable Zener Circuit Diagram

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How to Build a Programmable Zener Circuit Diagram. The ICL8212 is connected as a programmable zener diode. Zener voltages from 2 V up to 30 V can be programmed by mostly suitable selecting R2. The zener voltage is: Because of the absence of internal compensation in the ICL8212, CI is necessary to ensure stability. 
 
Two points worthy of note are the extremely low-knee current (less than 300 ) and the low dynamic impedance (typically 4 to 7 ohms) over the operating current range of 300 to 12 mA. 


Programmable Zener Circuit Diagram

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Simple 15V And 5V Car Battery Supply Circuit Diagram

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This is a Simple 15V And 5V Car Battery Supply Circuit Diagram. In this circuit use IC1 is a switching regulator that generates a 45-kHz signal that drives the gate of MOSFET Ql. Dl, D2, and D3 are Schottky diodes. The 5-V output is sensed as a reference; feedback to the chip turns off the gate signal to Ql if the voltage rises above 5 V. 

Tl has Trifilar windings that assume about 2% regulation for a 10-to 100-mA load change on the ± 15-V supplies. R1/D4 provide over-voltage protection. Tl has a primary inductance of about 21 . Core size should allow 4-A peak currents. The turn ratios are IIV2 turns each for the 15-V supplies, ll1/2 turns for the primary, and four turns for the 5-V secondary. The efficiency is about 75%.


Simple 15V And 5V Car Battery Supply Circuit Diagram

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Build a 12-14 Volt 3A - Anti-RF Filtered Power supply Circuit Diagram

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How to Build a 12-14 Volt 3A - Anti-RF Filtered Power supply Circuit Diagram. This is not easy but you can do it . This Anti-RF Filtered Power supply Circuit Diagram is dedicated for use with rf equipments like, linear amplifiers, transmitters, receivers, and in every application that clean an-noisy signal is required. 

The circuit is very simple and you can drive it with a 220V/18V/3A transformer at the pins 1and 2.The regulator used here is the LM350K and make sure you place a good heat-sink to it because it gets too hot if current gets near to 3A. 


12-14 Volt 3A - Anti-RF Filtered Power supply Circuit Diagram


Parts list
R1 = 220 Ohm 1/4W
R2 = 1,8 KOhm 1/4W
R3 = 330 Ohm 1/4W
 P1 = 100 Ohm
C1,C2,C3 = 4.700uf/25V
C4 = 100pf ceramic
C6 = 100uf/25V electrolitic
D1..4 = 1N5400-4 or RAX GI 837U
F1 = 5A
IC1 = LM350K

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Build a Bridge Circuit Diagram With One Power Supply

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This is simple Bridge Circuit Diagram With One Power Supply. For systems with only one power supply, two op amps act as instrumentation and buffer amps. The OPA111 AM buffers the reference mode of the bridge and applies that voltage to the instrumentation amps ref terminal. Output is taken between the amplifier outputs to exclude the fixed output offset. 

The additional op amp creates a bridge error of 2, where IB=bias current of op amp and R is the resistance of one leg of the bridge.


Build a Bridge Circuit Diagram With One Power Supply

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Build a 60Hz Power Inverter Circuit Diagram

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Hi Friends to we build a simple 60Hz Power Inverter Circuit Diagram.In the 60Hz Power Inverter Circuit Diagram Capacitor C5 and potentiometer R12 determine the frequency of the output signal at pin 3 of IC1, the 555 oscillator. The output signal is differentiated by C3 and C4 before it`s input to the base of power transistors Q1 and Q2 via diodes D1 and D2, respectively. 

The signal from !C1 is adjusted to 120Hz, because the flip-flop formed by transistors Q3 and Q4.divides the frequency by 2.When Q3 is on, the base of Q1 is connected via R1 to the regulated 12-V supply. Then, when the flipflop changes states, Q4 is turned on and the base of Q2 connected to the 12-V supply through R2. The 100 mA base current allowsQ1 and Q2 to alternately conduct through their respective halves to the transformer`s secondary winding. 


60Hz Power Inverter Circuit Diagram


To eliminate switching transients caused by the rapid switching of Q3 and Q4, capacitors C1 and C2 filter the inputs to the base of Q1 and Q2 respectively. Power for the unit comes from an automobile`s 12V system or from a storage battery. The power is regulated by IC2, a 7812 regulator. LED1, connected across the 12-V input, can be used to indicate whether power is being fed to the circuit. The neon pilot lamp, LMP1, shows a presence or absence of output power.


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Best Battery Charger Circuit Diagram

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Best it mean UJT battry charger circuit diagram. This UJT battry charger circuit diagram will not work unless the battery to  be charged is connected with proper polarity. The  battery voltage controls the charger and when the  battery is fully charged, the charger will not supply  current to the battery. The battery charging the  current is obtained through the SCR when it is triggered  into the conducting state by the UJT relaxation  oscillator. 

The oscillator is only activated when the battery voltage is low. V8281 of the UJT is derived from the voltage of the battery to be charged, and since Vp= Vn= V8281 ; the higher V828` the higher Vp. When Vp exceeds the breakdown voltage of the zener diode Zl, the UJT will cease to fire and the SCR will not conduct. This indicates that the battery has attained its desired charge as set by R2.


Best Battery Charger Circuit Diagram


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Build a Stand by Power Circuit Diagram for Non Volatile Cmos Rams

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This is  a simple Stand by Power Circuit diagram for Non Volatile Cmos Rams. To prevent loss of data when a CMOS RAM is switched from normal operation (Vcc = 5 volts) to stand-by mode (Vcc = VBAT) it must be ensured that the CS pin goes near the Vcc rail at all times. 

Ac coupling to the chip select is made through capacitor C, breaking the dc current path between Vqq (and hence VBAT) and the decoder output. So, whatever the impedance state of the decoder in power down, the battery will provide current only for the RAM, low enough to keep the voltage at CS near to V^.

Power Circuit Diagram

Build a Stand by Power Circuit Diagram for Non Volatile Cmos Rams Circuit diagram

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Simple 8-Amp Regulated Power supply Circuit Diagram

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This Simple 8-Amp Regulated Power supply Circuit Diagram is powered by a transformer operating from 120 Vac on the primary and providing approximately 20 Vac on the primary, and providing approximately 20 Vac on the secondary. Four 10-A diodes with a 100 PIV rating are used in a full-wave bridge rectifier. A 10,000 ^F/36 Vdc capacitor completes the filtering, providing 28 Vdc. 

The dc voltage is fed to the collectors of the Darling-ton connected 2N3055's. Base drive for the pass transistors is from pin 10 of the µ723 through a 200 ohm current limiting resistor, Rl. The reference terminal (pin 6) is tied directly to the non-inverting input of the error amplifier (pin 5), providing 7.15 V for comparison. The inverting input to the error amplifier (pin 4) is fed from the center arm of a 10 k ohm potentiometer connected across the output of the supply.


Simple 8-Amp Regulated Power supply Circuit Diagram

This control is set for the desired output voltage of 13.8 V. Compensation of the error amplifier is accomplished with a 500 pF capacitor connected from pin 13 to pin 4. If the power supply should exceed 8 A or develop a short circuit, the µ723 regulator will bias the transistors to cutoff and the output voltage will drop to near zero until the short circuit condition is corrected.
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Best Electronic Crowbar Circuit Diagram for AC or DC lines

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This is Best Electronic Crowbar Circuit Diagram for AC or DC lines. For positive protection of electrical or electronic equipment, use this against excessive supply voltage. Due to improper switching, wiring, short circuits, or failure of regulators, an electronic crowbar circuit can quickly place a short circuit across the power lines, thereby dropping the voltage across the protected device to near zero and blowing a fuse. 

The triac and SBS are both bilateral devices, the circuit is equally useful on ac or dc supply lines. With the values shown for Rl, R2, and R3, the crowbar operating point can be adjusted over the range of 60 to 120 volts dc or 42 to 84 volts ac. The resistor values can be changed to cover a different range of supply voltages. The voltage rating of the triac must be greater than the highest operating point as set by R2, II is a low power incandescent lamp with a voltage rating equal to the supply voltage. 


Best Electronic Crowbar Circuit Diagram for AC or DC lines

It may be used to check the set point and operation of the unit by opening the test switch and adjusting the input or set point to fire the SBS. An alarm unit such as the Mallory Sonalert may be connected across the fuse to provide an audible indication of crowbar action. (This circuit may not act on short, infrequent power line transients).
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Build a Simple Dual Polarity Power supply Circuit Diagram

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This is the Simple Dual Polarity Power supply Circuit Diagram. This simple Dual Polarity Power supply Circuit Diagram gives a positive and negative supply from a single transformer winding and one full-wave bridge. Two zener diodes in series provide the voltage division and their centerpoint is grounded. The filter capacitor must not be grounded via its case.

 Dual Polarity Power supply Circuit Diagram

Dual Polarity Power supply Circuit Diagram

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Build a Photomultiplier Circuit Diagram

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How to Build a Photomultiplier Circuit Diagram? This Photomultiplier Circuit Diagram is typical of the way that a photomultiplier tube is used. The circuit shown is ac coupled, but if dc coupling is needed, the capacitor can be omitted and a suitable interfacing method used. A typical tube is the widely available 931/931A.


Photomultiplier Circuit Diagram

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Simple Rf Probe Circuit Diagram For vtvm

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This Simple Rf Probe Circuit Diagram combines a 555 timer with a 2N2222 transistor and an external potentiometer. The pot adjusts the output voltage to the desired value. To regulate the output voltage, the 2N2222 varies the control voltage of the 555 IC, increasing or decreasing the pulse repetition rate. A 1 K resistor is used as a collector load. The transistor base is driven from the external pot

Simple Rf Probe Circuit Diagram

Simple Rf Probe Circuit Diagram

If the output voltage becomes less negative, the control voltage moves closer to ground, causing the repetition rate of the 555 to increase, which, in turn, causes the 3 µf capacitor to charge more frequently. Output voltage for the circuit is 0 to 10 V, adjusted by the external pot. Output regulation is less than five percent for 0 to 10 mA and less than 5 percent for 0 to 0 mA.
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Best Power Protection Circuit Diagram

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This is the Best Power Protection Circuit Diagram for you. (Read Power supply Protection Circuit Diagram ) To safeguard portable, emergency power repeaters from reverse or excessive voltage, Dl prevents incorrect polarity damage, and zener voltage determines the maximum voltage that will reach the rest of the circuitry. Use fast blowing fuse rated greater than the SCR current rating.


Best Power Protection Circuit Diagram

Best Power Protection Circuit Diagram

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New Automatic Shutoff Battery Charger Circuit Diagram

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This is a New Automatic Shutoff Battery Charger Circuit Diagram. This automatic shutoff battery charger circuit diagram Adjust by setting the 500 ohm resistor while attached to a fully charged battery.


New Automatic Shutoff Battery Charger Circuit Diagram

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How to Build a Long Line Ir Drop Voltage Recovery Circuit Diagram? This Simple Long Line Ir Drop Voltage Recovery Circuit Diagram provides a unique solution to a common system-level power distribution problem: When the supply voltage to a remote board must traverse a long cable, the voltage at the end of the line sometimes drops to unacceptable levels. 

This + 5-V/ + 5-V converter addresses this by taking the reduced voltage at the end of the supply line and boosting it back to + 5 V. This can be especially useful in remote display devices, such as some point-of-sale (POS) terminals, where several meters of cable could separate the terminal from the readout.


Build a Long Line Ir Drop Voltage Recovery Circuit Diagram

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This is a Simple Portable Nicad Battery Charger Circuit Diagram. This Simple Portable Nicad Battery Charger Circuit Diagram was designed to charge NiCad battery packs in the range of 4.8 to 15.6 V from a convenient remote power source, such as an automobile batter. 



Portable Nicad Battery Charger Circuit Diagram

When power is first applied to the circuit, a small bias current supplied by Rl via winding Wl, starts to turn on the transistor TRl. This forces a voltage across W2 and the positive feedback given by the coupling of Wl and W201uses the transistor to turn hard on, applying the full supply across W2. The base drive voltage induced across Wl makes the junction between Rl and R2 become negative with respect to the 0-V supply, forward-biasing diode Dl to provide the necessary base current to hold TRl on. 

With the transistor on, a magnetizing current builds up in W2, which eventually saturates the ferrite core of transformer Tl. This results in a sudden increase on the collector current flowing through TRl, causing its collector-emitter voltage to rise, and thus reducing the voltage across W2. 

The current flowing in W2 forces the collector voltage of the TRl to swing positive until restricted by transformer output loading. Rc network R4 and C3limits the turn off transient TRl. R3 and C2 maintain the loop gain of the circuit when diode Dl is not conducting.
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Best Telecom Converter Circuit Diagram

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This is the Simple but Best Telecom Converter Circuit Diagram.The circuit supplies 1 A at +5 V from the -48-V supply commonly used in telephone equipment. The National Semiconductor LM2575 is a simple switching regulator.


Best Telecom Converter Circuit Diagram

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Simple Bilateral Current Source Circuit Diagram

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Hi Friends ! I am sorry for don't update i post because i am busy few days. OK to day share with you Simple Bilateral Current Source Circuit Diagram This circuit uses a CA3193 precision op amp to deliver a current independent of variations in RL. 

With RI set equal to R3, and R2 approximately equal to R4 + R5, the output current, h. is: VlN (R4)/(R3) (R5). 500-I`A load current is constant for load values from 0 to 3ohm.


Simple Bilateral Current Source Circuit Diagram

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Build a Inexpensive Isolation Transformer Circuit Diagram

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Build a Inexpensive Isolation Transformer Impromptus Setup Circuit Diagram. Using two 12-V filament or power transformers, an impromptu isolation transformer can be made for low-power (under 50 W) use in testing or servicing. SOI is an ordinary, duplex ac recept-able. Use heavy-wire connections between the 12-V windings because several amperes can flow.



Inexpensive Isolation Transformer Circuit Diagram

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Simple But best Regulator Circuit Diagram

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This is the Simple But best Regulator Circuit Diagram.The best characteristic of this regulator is that the output voltage can be adjusted down to 0 V. The regulation is provided by an integrated regulator Type LM317. As is normal in supplies that can be adjusted to 0 V, this IC is used in conjunction with a zener diode. This diode provides a reference voltage that is equal, but of opposite sign, to the reference voltage (U,) of the regulator, as shown in Fig. 74-1 (a). 

Potential divider R1/R2 enables the output voltage to be adjusted. In this circuit, the negative reference voltage is derived in a different manner: from the regulator with the aid of an op amp (Fig. 74-1 (b)). The op amp is connected as a differential amplifier that measures the voltage across Rl and inverts this voltage to Ur. An additional advantage of this method is that at low-output voltages, a change in the reference voltage has less effect on the output voltage than the circuit in Fig. 74-1 (a). The prototype, constructed as shown in Fig. 74-1 (c), gave very satisfactory results. 


Simple But best Regulator Circuit Diagram


The op amp need not meet any special requirements: a 741 works fine, although an LF356 gives a slightly better performance. The negative supply for the op amp can be obtained with the aid of a center-tapped mains transformer.
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Value able 40W 120Vac Inverter Circuit Diagram

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This is the Value able 40W 120Vac Inverter Circuit Diagram. This  40W 120Vac Inverter Circuit Diagram uses a 12.6-V to 120-V transformer to deliver a quasi-sine wave that has the same rms and peak voltage as a pure sine wave. Q1 to Q6 must be heatsinked. A 1.5` 4` aluminum heatsink was used on the prototype. 

The transformer should be a 3-A unit. The 40W 120Vac Inverter Circuit Diagram uses feedback to help regulate the output voltage to 120 Vac. Notice that the output frequency is 75 Hz to avoid saturating the core of T1.


 40W 120Vac Inverter Circuit Diagram

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Build a 3V Battery To 5V Dc/Dc Converter Circuits Diagram

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Build a 3V Battery To 5V Dc/Dc Converter Circuits Diagram. A common power-supply requirement involves converting a 2.4- or 3-V battery voltage to a 5-V logic supply. This circuit converts 3 V to 5 V at 40 mA with 85% efficiency. When Ic (pin 6) is driven low, the output voltage will be the battery voltage minus the drop across diode Dl. 

The optional circuitry that uses CI, R3, and R4 lowers the oscillator frequency when the battery voltage falls to 2.0 V. This lower frequency maintains the output-power capability of the circuit by increasing the peak inductor current, which compensates for the reduced battery voltage.


Build a 3V Battery To 5V Dc/Dc Converter Circuits Diagram

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This High-Voltage Supply Circuit Diagram uses a transistor oscillator and a voltage multiplier to charge CIO and CI 1 to a high voltage. When the spark gap breaks down, T2 produces a high-voltage pulse via the capacitance discharge of CIO and Cll into its primary. T2 is an auto ignition coil.

Read : High-Voltage Pulse Supply Circuit Diagram



High-Voltage Supply Circuit Diagram

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Basic 12V Output To 5V Buck Regulator Circuit Diagram

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This is 12V Output To 5V Buck Regulator Circuit Diagram. By adding a flyback winding to a buck-regulator switching converter (see the figure), wliich is essentially a 5-V supply with a 200-mA output capability, a 12-V output ) can be produced. 

The flyback winding on the main inductor (forming transformer Tl) enables an additional low- dropout linear regulator (IC2) to create the 12-V output voltage that`s needed to program EEPROMs.The required input voltage is 8 to 16 V.



12V Output To 5V Buck Regulator Circuit Diagram

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