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Showing posts from August, 2013

Simple Low Power Switching Regulator Circuit Diagram

This is the Simple Low Power Switching Regulator Circuit Diagram. A simple battery-powered switching regulator provides 5 V out from a 9-V source with 80% efficiency and 50 mA output capability. When Q1 is on, its collector voltage rises, forcing current through the inductor. The output voltage rises, causing A1`s output to rise. 
Low Power Switching Regulator Circuit Diagram


Q1 cuts off and the output decays through the load. The 100-pF capacitor ensures clean switching. The cycle repeats when the output drops1ow enough for A1 to turn on Ql. The 1-

Build a Power supply Protection Circuit Diagram

Why Build aPower supply Protection Circuit Diagram. When using a regulated supply to reduce a supply voltage there is always the danger of component failure in the supply and consequent damage to the equipment. A fuse will protect when excess current is drawn, but might be too slow to cope with over voltage conditions. The values shown are for a 12 V supply being dropped to 5 V.
Power supply Protection Circuit Diagram



The trip voltage is set to 5.7 V to protect the equipment in the event of a regulator fault. The 330 ohm resistor and the 500 ohm potentiometer form a potential divider which samples the output voltage as set by adjustment of the potentiometer. The SCR is selected to carry at least twice the fuse rating. The full supply voltage is connected to the input of the regulator.

The 2N2906 is held bias off by the 10 k resistor and the SCR so that the LED is held off. If the output voltage rises above a set trip value then the SCR will conduct, the fuse will blow, and the 2N3906 w…

Memory Save on Power down Circuit Diagram

Memory Save on Power down Circuit Diagram. The auxiliary output powers the memory, while the main output powers the system and is connected to the memory store pin. When power goes down, the main output goes low, commanding the memory to store. The auxiliary output then drops out.
Memory Save on Power down Circuit Diagram
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Simple Relay Fuse For Battery Charges Circuit Diagram

This is a Simple Relay Fuse For Battery Charges Circuit Diagram. Charged capacitor C3 and momentary pushbutton switch S2 are used to momentarily energize relay RE 2. The batteiy under charge energizes the relay to hold it closed. S2 will energize the relay even if the battery is too far discharged initially to energize it.
Relay Fuse For Battery Charges Circuit Diagram

Off line Fly back Regulator Circuit Diagram

This Off line Fly back Regulator Circuit Diagram uses a low-cost feedback scheme in which the dc voltage developed from the primary-side control winding is sensed by the UC1842 error amplifier. Load regulation is therefore dependent on the j coupling between secondary and control windings, and on transformer leakage inductance. 
For applications requiring better load regulation, a UC1901 Isolated Feedback Generator can be used to directly sense the output voltage.
Off line Fly back Regulator Circuit Diagram

Single Supply fault Monitor Circuit Diagram

This Single Supply fault Monitor Circuit Diagram shows a typical over/under-voltage fault monitor for a single supply. The upper trip points, controlling OUT 1, are centered on 5.5 V with 100 mY of hysteresis Wu = 5.55 V, `L = 5.45 V); and the lower trip points, controlling OUT 2, are centered on 4.5 V, also with 100 mV of hysteresis. OUT 1 and OUT 2 are connected together in a wired OR configuration to generate a power OK signal.

Single Supply fault Monitor Circuit Diagram

Low power Dc-Dc Converter Circuit Diagram

This low-power converter will supply about 100 mW of dc to a load and it is useful to isolate or derive dc voltages. It operates at around 200 kHz. LI is wound on a 22-mm diameter 13-mm high pot core with #32 magnet wire. The primary is 80 turns and the secondary is 80 turns (for 12- V nominal output). The two windings should be insulated for the expected voltage difference between input and output in insulation applications. 
Low power Dc-Dc Converter Circuit Diagram

Simple 250W Inverter Circuit Diagram

This is a simple 250W Inverter Circuit Diagram. A 555 timer (IC1) generates a 120-Hz signal that is fed to a CD4013BE flip-flop (ICl-a), which divides the input frequency by two to generate a 60-Hz clocking frequency for the FET array (Ql through Q6). Transformer Tl is a 12-/24-V center-tapped 60-Hz transformer of suitable size. 
250W Inverter Circuit Diagram


High-Voltage Pulse Supply Circuit Diagram

This high-voltage pulse supply will generate pulses up to 30 kV. Ql and Q2 form a multivibrator in conjunction with peripheral components Rl through R6 and CI, C2, C3, C5, C6, and D2. R9 adjusts the pulse repetition rate. R2 should be selected to limit the maximum repetition rate to 20 Hz. II is a type 1156 lamp used as a current limiter. 
R9 can be left out and R2 selected to produce a fixed rate, if desired. Try about 1 as a start. Q3 serves as a power amplifier and switch to drive Tl (an automotive ignition coil). NE1 is used as a pulse indicator and indicates circuit operation. Because this circuit can develop up to 30 kV, suitable construction techniques and safety precautions should be observed.
High-Voltage Pulse Supply Circuit Diagram


The High Voltage Geiger Counter Supply Circuit Diagram

This High Voltage Geiger Counter Supply Circuit Diagram will generate about 300 volts dc —at a very low current, but enough for a GM tube. be careful with the output.


High Voltage Geiger Counter Supply Circuit Diagram


Build a Low Power Consumption 5V Regulator Circuit Diagram

How to build a Low Power Consumption 5V Regulator Circuit Diagram? The special feature of the circuit shown below is the low consumption. With voltage n 9 at the entrance and no exit load, absorbs current 50 ma, which is certainly very small compared with a quiescent current 78L05. The components that comprise it are scarce. Just a reference voltage source, formed by the T1 and the IC 1 and an amplifier consisting of the IC2 and T2 so we have to output the desired voltage stabilizer. 
The trend that emerges at the output of IC 1 increased to 1,22 V. Using the IC2 and the P1 is set so that the output of the circuit is n equal to 5 exactly at the entrance of the circuit can be imposed voltage between 6.5 ??? 30 V DC, while the maximum output current reaches 1 mA for the better functioning of the stabilizer, transistors T and T 1 a 1 b should be possible similar characteristics. That is why we preferred a 'double' type transistors MAT02 or alternatively one of the MAT01, SSM2210 o…

Simple Bilateral Current Source Circuit Diagram

The Simple Bilateral Current Source Circuit Diagram will produce the current relationship to within 2% using 1% values for Rl through R5. This includes variations in Rl from 100 ohm to 2000 ohm. The use of large resistors for Rl through R4 minimizes the error due to Rl variations. The large resistors are possible because of the excellent input bias current performance of the OP-08,.
Simple Bilateral Current Source Circuit Diagram

Shift Register Driver Power Supply Circuit Diagram

This is the Shift Register Driver Power Supply Circuit Diagram. A16 V power supply can be synthesized as shown using IN1692 rectifiers. A shift pulse input saturates the 2N2714 depriving the Darling-ton combination (2N2714 and 2N2868) of base drive.The negative pulse so generated on the 15 V line is differentiated to produce a positive trigger pulse at its trailing edge.
Shift Register Driver Power Supply Circuit Diagram

Simple Self Oscillating Switching Converter Circuit Diagram

This is a Simple Self Oscillating Switching Converter Circuit Diagram. Regulation is provided by taking the rectified output of the sense winding and applying it as a bias to the base of Q2 via zener Dl. The collector of Q2 then removes drive from the gate of Ql. 
Therefore, if the . output voltage should increase, Q2 removes the drive to Ql earlier, shortening the on time, and the output voltage will remain the same. De outputs are obtained by merely rectifying and filtering secondary windings, as done by D5 and C4.
Self Oscillating Switching Converter Circuit Diagram

Build a Positive input Negative output Charge pump Circuit Diagram

How to Build a Positive input Negative output Charge pump Circuit Diagram. A simple means of generating a low-power voltage supply of opposite polarity from the main supply. Self oscillating driver produces pulses at a repetition frequency of 100 kHz. 
When the VMOS device is off, capacitor C is charged to the positive supply. When the VMOS transistor switches on, C delivers a negative voltage through the series diode to the output. The zener serves as a dissipative regulator.
Positive input Negative output Charge pump Circuit Diagram

Simple Photomultiplier Supply Circuit Diagram

This is a Simple Photomultiplier Supply Circuit Diagram and Cockcroft-Walton voltage multiplier supplies the stepped voltage required for the dynodes of the PMT without the power-wasting voltage- divider resistor string that is traditionally used.
Simple Photomultiplier Supply Circuit Diagram

Build a Regulated driven Converter Circuit Diagram

How to Build a Regulated driven Converter Circuit Diagram?.This converter delivers up to 50 mA from a 6-V battery with 78% efficiency. This flyback converter functions by feedback-controlling the frequency of inductive flyback events. The inductor`s output, rectified and filtered to de, biases the feedback loop to establish a stable output. If the converter`s output is below the loop setpoint, A2`s inputs unbalance and current is fed through the 1-MO resistor at Al. This ramps the 1000-pF value positive. When this ramp exceeds the 0.5-V potential at A1 `s positive input, the amplifier switches high. 
Regulated driven Converter Circuit Diagram


Q2 turns on, discharging the capacitor to ground. Simultaneously, regenerative feedback through the 200-pF value causes a positive-going pulse at A1`s positive input, sustainlljg A1`s positive output. Q1 comes on, allowing inductor, 11, current to flow. When A1`s feedback pulse decays, its output becomes low, turning off Ql. Q1`s collector is pulle…

Simple Dual 50V/5A Universal Power Supply Circuit Diagram

This is the simple Dual 50V/5A Universal Power Supply Circuit Diagram. Tl has two primaries and six secondaries; the two 120-VAC primaries and 6.3-VAC secondaries are in parallel. Modules A and are identical; hence, only Module A`s parts are called out. Module C is wired point-to-point on the IC3 heat-sink.
Dual 50V/5A Universal Power Supply Circuit Diagram

Simple Positive Regulator Circuit Diagram

In the Simple Positive Regulator Circuit Diagram, Ql and Q2 are connected in the classic SCR or thyristor configuration. Where higher input voltages or minimum component count are required, the circuit for thyristor boost can be used. 
Positive Regulator Circuit Diagram


The thyristor is running in a linear mode with its cathode as the control terminal and its gate as the output terminal. This is known as the remote base configuration.

Top Bench Power supply Circuit Diagram

This is the Top Bench Power supply Circuit Diagram. A tapped transformer drives a diode bridge (D1-D4) and two 2500 µ¥ filter capacitors (Cl and C2), that provide a no-load voltage of 37 or 47 volts, depending upon the position of switch S2a. The unregulated dc is then fed to a pre-regulator stage composed of Ql and D5. 
Those components protect IC1 (the 723) from an over-voltage condition; the 723 can't handle more than 40 volts. The LED (LED1) and its 2.2 k current-limiting resistor (Rl) provide on/off indication. The current through the LED varies slightly according to the transformer tap selected, but that's of no real consequence.
 Top Bench Power supply Circuit Diagram

 The series-pass transistor in IC1 drives voltage-follower Q2, providing current amplification. The transistor can handle lots of power. It has a maximum collector current of 15 amps and a maximum VCE of 70 V, both of which are more than adequate for our supply.

Simple Fixed-Current Regulator Circuit Diagram

This Simple Fixed-Current Regulator Circuit Diagram 1-mA current source delivers a fixed current to a load connected between Ql`s collector and ground; the load can be anywhere in the range from 0 to 14 . The circuit is powered from a regulated 15-V supply, and the R1/R2 voltage divider applies a 14-V reference to R3. 
The op amp`s output automatically adjusts to provide an identical voltage at the junction of R4 and R5. That produces 1 V across R5, resulting in an R5 current of 1 mA. Because that current is derived from Ql`s emitter, and the emitter and collector currents of a transistor are almost identical, the circuit provides a fixed-current source. The output current can be doubled by halving the value of R5.
Fixed-Current Regulator Circuit Diagram

Over voltage Protection Circuit Diagram

This is a Over voltage Protection Circuit Diagram. A silicon-controlled rectifier is installed in parallel with the 12-V line and connected to a normally-closed 12-V relay, K1. The SCR's gate circuit is used to sample the applied voltage. As long as the applied voltage stays below a given value, SCR1 remains off and Kl's contacts remain closed, thereby supplying power to the load. 
When the source voltage rises above 12 V, sufficient current is applied to the gate of SCR1 to trigger it into conduction. The trigger point of SCR1 is dependent on the setting of R1. Once SCR1 is triggered (activating the relay), K1's contacts open, halting current flow to the load.
Over voltage Protection Circuit Diagram

Build a Bridge balance indicator Circuit Diagram

How to Build a Bridge balance indicator Circuit Diagram. This Indicator circuit provides an accurate comparison of two voltages by indicating their degree of balance (or imbalance). Detecting small variations near the null point is difficult with the basic Wheatstone bridge alone. Amplification of voltage differences near the null point will improve circuit accuracy and ease of use. The 1N914 diodes in the feedback loop result in high sensitivity near the point of balance (R1/R2 = R3/R4). 
When the bridge is unbalanced the amplifier's closed-loop gain is approximately Rp/r, where r is the parallel equivalent of Rl and R3. The resulting gain equation is G = RF(1/R1 + 1/R3). During an unbalanced condition the voltage at point A is different from that at point B.
This difference voltage (V^), amplified by the gain factor G, appears as an output voltage, As the bridge approaches a balanced condition (R1/R2 = R3/R4), V^ approaches zero. As V^ approaches zero the 1N914 diodes in the feedb…

Simple Bridge Rectifier Circuit Diagram

This Simple Bridge Rectifier Circuit Diagram is intended for those cases where two unequal supply voltages are required. The lower voltage is obtained with the aid of a transformer with symmetric windings and half-wave rectification of the potential across one winding. For the higher voltage, the potential across both windings is rectified. To that end, the output of the transformer is linked to the bridge rectifier via two electrolytic capacitors that provide isolation of the two direct voltages. 
 Simple Bridge Rectifier Circuit Diagram


A bonus with this type of circuit is that although the two supplies can be loaded unequally, the currents through the two transformer windings are the same. Thus, the transformer is loaded symmetrically so that its full capacity can be used. Moreover, no unnecessary dissipation is in the voltage regulators. The load on the lower voltage supply depends primarily on the rating of the transformer. The load on the higher voltage supply is limited by the re…

Build a Regulated Charge Pump Circuit Diagram

How to Build a Regulated Charge Pump Circuit Diagram. The dc-dc converter substitutes a voltage triplet in place of the external inductor and the diode that`s typically associated with the switching regulator, IC1. Inverting and non inverting amplifiers in the MOS-FET-driver (IC2) activate a diode-capacitor tripling network (D1 through D3, CI through C3). 
A 50-kHz oscillator residing within IC1 produces the EXT signal (pin 6), IC2 converts this signal into drive signals (180° out of phase) for the tripler. The resulting charge-discharge action in the capacitors recharges C3 toward 10 V every 20 The ferrite bead limits output ripple to about 20-mVpp for a 50-mA load. Conversion efficiency is about 70% for the 5-V input, 10-V output configuration.
Regulated Charge Pump Circuit Diagram

Simple Voltage controlled current source with grounded source and load

This is a Simple Voltage controlled current source with grounded source and load. This is a simple, precise voltage-controlled current source. Bipolar supplies will permit bipolar output. Configurations featuring a grounded voltage- control source and a grounded load are usually more complex and depend upon several components for stability.Voltage-controlled-current-source-with-grounded-source-and-load. In this circuit, accuracy and stability almost entirely depend upon the 100-0 shunt.
Voltage controlled current source circuit diagram


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Simple Positive And Negative Voltage Power Supply Circuit Diagram

This Simple Positive And Negative Voltage Power Supply Circuit Diagram provides a precision voltage source that can be adjusted through zero to positive and negative voltages, which eliminates reversing connections on the power supply. Also, it is possible to get exactly 0 V, without some offset. As to how this circuit works, first consider the -1 V/V to +1 V/V linear gain-control amp (see the figure). A Burr-Brown INA105 difference amp is used in a unity-gain inverting amp configuration. 
Positive And Negative Voltage Power Supply Circuit Diagram


A potentiometer is connected between the input and ground. The pot`s slider is connected to the noninverting input of the unity-gain amp; this input is typically connected to ground. With the slider at the bottom of the pot, the circuit is a normal-precision unity-gain inverting amp with a gain of -1.0 V/V ± 0.01% maximum. 
With the slider at the top of the pot, the circuit is a normal-precision voltage follower with a gain of ± 1.0 V/V ± 0.…

Simple Power Converter Circuit Diagram

This simlpe Power Converter Circuit Diagram consists of an a stable multivibrator driving a push-pull pair of transistors into the transformer primary. The multivibrator frequency should~equal around 1 or 2kHz. For higher de voltages, voltage multipliers on the secondary circuit have been used successfully to generate 10 k V from a 40~stage multiplier like the one shown.

Power Converter Circuit Diagram


Build a High Voltage Inverter Circuit Diagram

The High Voltage Inverter Circuit Diagram converts a de voltage (V +) to a high-amplitude square wave in the audio-frequency range. The dual timer, IC2, provides an inexpensive alternative to the traditional transformer for providing complementary base drive to the power transistors, Ql and Q2. You can convert a 6 to 12 V battery output, for example, to an ac amplitude, which is limited primarily by the power rating of transformer Tl. 
Connect timer IC1 as an oscillator to provide a symmetrical square-wave drive to both inputs of IC2. The timing components, R2 and Cl, produce a 2.2-kHz output frequency. By connecting half of IC2 in the inverting mode and the other half in noninverting mode, the timer`s outputs alternately drive the two transistors. 
 Build a High Voltage Inverter Circuit Diagram


You can operate the audio-output transformer, Tl, as a step-up transformer by connecting it backwards using the output winding as an input. The transformer delivers an output voltage across RL of…

Twin Audio Amplifier Power Supply Circuit Diagram

A Twin Audio Amplifier Power Supply Circuit Diagram that will deliver 50 W per channel is shown in the schematic. It includes preamp and tone controls, and also includes a headphone amplifier. The circuit depicts the power supply that supplies 38.5 V and 15 V regulated for the dual 50 watt.

Twin Audio Amplifier Power Supply Circuit Diagram


Medium Power Inverter Circuit Diagram

In this Medium Power Inverter Circuit Diagram, a CMOS inverter, such as the CD4069, is used to convert the open drain Lx output to a signal suitable for driving the gate of an external P MOSFET. The MTP8P03 has a gate threshold voltage of 2.0 V to 4.5 V, so it will have a relatively high resistance if driven with only 5 V of gate drive. 
To increase the gate drive voltage, and thereby increase efficiency and power handling capability, the negative supply pin of the CMOS inverter is connected to the negative output, rather than to ground. Once the circuit is started, the P MOSFET gate drive swings from +5 V to -Vour· At start up, the -Vour is one Schottky diode drop above ground and the gate drive to the power MOSFET is slightly less than 5 V. 
Medium Power Inverter Circuit Diagram

The output should be only lightly loaded to ensure start up, since the output power capability of the circuit is very low until -VoUT is a couple of vults. This circuit generates complementary output signals f…

Simple 3V Power Supply Circuit Diagram For Portable Radios

This is the Simple 3V Power Supply Circuit Diagram For Portable Radios. Most small portable radios require a 3-V supply, which is normally provided by two AA or AAA batteries .Because rechargeable batteries are an option with many of these radios, most of them are fitted with a charger socket. When such radios are used in a stationary condition (e.g., in the kitchen or in the office), it is useful (and economical) to use the mains-operated supply described here. 
The supply is small enough to be fitted inside the radio or in a mains adapter case (less than transformer). Voltage regulator IC1 is adjusted for an output of 3 V by resistors RI and R2, which are decoupled by C2. Capacitor C3 provides additional filtering. Diode D1 indicates whether the unit has been connected to the mains. The diode also provides the load necessary for the regulator to function properly; in its absence, the secondary voltage of the transformer might become too high when the unit is not loaded. 
The transform…

Build a Isolated 15V To 2500V Power Supply Circuit Diagram

Build a Isolated 15V To 2500V Power Supply Circuit Diagram. A dc-dc converter using a 74HC04 drives Tl. Tl is a ferrite-core transformer using a Fair-Rite, Inc. P/N 5975000201 (uo + 5000) and has a 7-turn primary and a 25-turn secondary. Kynar, #30 wirewrap wire is used. With Tl, the circuit isolation is good to 2500 V.
Isolated 15V To 2500V Power Supply Circuit Diagram


Simple Wind battery Charger Circuit Diagram

This is a Simple Wind battery Charger Circuit Diagram. The dc motor is used as a generator with the voltage output being proportional to its rpm. The LTC1042 monitors the voltage output and provides the following control functions. If generator voltage output is below 13.8 V, the control circuit is active and the Ni-Cad battery is charging through the LM334 current source. The lead acid battery is not being charged. 
If the generator voltage output is between 13.8 V and 15.1 V, the 12 V lead acid battery is being charged at about 1 amp/hour rate (limited by the power FET). If generator voltage exceeds 15.1 V (a condition caused by excessive wind speed or 12 V battery being fully charged) then a fixed load is connected limiting the generator rpm to prevent damage. This charger can be used as a remote source of power where wind energy is plentiful such as on sailboats or remote radio repeater sites. Unlike solar powered panels, this system will function in bad weather and at night.
Simpl…

Build a 200Ma-12v ni-cad Battery Charger Circuit Diagram

This 200Ma-12v ni-cad Battery Charger Circuit Diagram charges the battery at 75 mA battery can be left in the charger indefinitely, until the battery is charged, then it reduces the To set the shut-off point, connect a 270-ohm, current to a trickle rate
It will completely 2-watt resistor across the charge terminals and recharge a dead battery in four hours and the adjust the pot for 15 volts across the resistor. 
 200Ma-12v ni-cad Battery Charger Circuit Diagram

Simple Microprocessor power supply watchdog circuit Diagram

The Simple Microprocessor power supply watchdog circuit Diagram monitors the input to the microprocessor 5 V regulated supply for voltage drops and initiates a reset sequence before supply regulation is lost. In operation, the resistor capacitor combination Rs and Cj form a short time constant smoothing network for the output of the fullwave bridge rectifier. 
An approximately triangular, voltage waveform appears across C and Rs and it is the minimum excursion of this that initiates the reset. Diode Dg prevents charge sharing between capacitors Cj and Ck. Resistors Rn and Rm form a feedback network around the voltage reference section of the LM10C, setting a threshold voltage of 3.4 volts. 
Microprocessor power supply watchdog circuit Diagram


The threshold voltage is set at 90% of the minimum voltage of the triangular waveform. When the triangular wave trough, at the comparators non-inverting input, dips below the threshold, the comparator output is driven low. This presents a reset to t…

Safe Constant Current Source Circuit Diagram

In the Safe Constant Current Source Circuit Diagram shown, a CMOS op amp controls the current through a p-channel HEXFET power transistor to maintain a constant voltage across RL The current is given by: 1 ~ VREF/Rl. The advantages of this configuration are: (a) in the event of a component failure, the load current is limited by Rl; and (b) the overhead voltage needed by the op amp and the HEXFET is extremely low.

Safe Constant Current Source Circuit Diagram

Build a Heavy Duty Battery Charger Circuit Diagram

How to Build a Heavy Duty Battery Charger Circuit Diagram. Operation amplifier A1 directly drives the VN64GA with the error signal to control the output voltage. Peak rectifier Dl, CI supplies error amplifier A1 and the reference zener. This extra drive voltage must exceed its source voltage by several volts for the VN64GA to pass full load current. 
The output voltage is pulsating dc which is quite satisfactory for battery charging. To convert the system to a regulated dc supply, capacitor C2 is increased and another electrolytic capacitor is added across the load. The response time is very fast, being determined by the op-amp. 
 Heavy Duty Battery Charger Circuit Diagram


The 2N4400 current limiter circuit prevents the output current from exceeding 4.5 A. However, maintaining a shorted condition for more than a second will cause the VN64GA to exceed its temperature ratings. A generous heat sink, on the order of 1°C/W, must be used.

Very Low Dropout Linear Regulator Circuit Diagram

This linear post regulator provides 12 V at 3 A. It employs TL431 reference Ul which, without additional amplification, drives TMOS MTP3055A gate Ql series pass regulator. Bias voltage is applied through Rl to Q1`s gate, which is protected against overvoltage by diode CRl. 
Frequency compensation for closed-loop stability is provided by Cl. Key performance features are: Dropout voltage: 0.6 V Load regulation: lOmV Line regulation: ± 5 m V Output ripple: 10 mVpk-pk
Low Dropout Linear Regulator Circuit Diagram

Basic DC to DC Converter Electronic Schematic Diagram

Those of you who frequently use devices that work on battery or you need a negative trend at the moment you have a single positive, will definitely look for a converter like the one described below. Constructing it, you can convert a positive voltage of a battery of 9 V to negative using well known integrated 555. The same circuit can also be used in cases those requiring two symmetrical lines of power, when available a single battery. 
The integrated TLC555 is the old bipolar NE555, manufactured with technology but CMOS. Unless you have this type of integrated, you might as well use an 7555. In this construction, the TLC555 is syndesmologimeno arranged in a ground unstable.The oscillation frequency determined by the A2, A3, C 1 and approaching 20 kHz. 
 DC to DC Converter Electronic Schematic Diagram


The rectangular waveform produced by the oscillator is therefore time to time (Duty Cycle) close to 50%. The waveform is led to a rectifier Doubler formed by C3, O1, O2 and C4. In place of …

Simple Inductance Bridge Circuit Diagram

This Inductance Bridge Circuit Diagram will measure inductances from about 1 to 30 at a test frequency of 5 mHz. A 365-pF AM-type tuning capacitor is used as a variable element. The circuit should be constructed in a metal enclosure. Calibration can be done on known inductors or by plotting a curve of the capacitance of the 365-pF capacitor versus rotation and calculating the inductance from this. 
The range of measurement can be charged by using a different frequency crystal and/or variation of L2 and C6.
Inductance Bridge Circuit Diagram

Coming Soon: The Slicker, Faster and – Maybe – Cheaper iPhone

Excitement over the new iPhone is building to a frenzy this week as rumors abound that Apple (AAPL) will unveil upgraded models on September 10. That would be almost exactly a year after Apple introduced the iPhone 5, which grabbed the title of best selling smart phone model in the world last year.
Apple isn’t commenting on new models yet but the September 10 introduction date has been confirmed by major news organizations including the Wall Street Journal’s AllThingsD and dedicated Apple bloggers such as Jim Dalrymple.
The rumored new handset, expected to be called the iPhone 5S, will probably look quite similar to the current model 5 but is sure to be lighter and more powerful than ever. It may also be accompanied by a lower-priced, plastic-cased model, dubbed the iPhone “5C” on the Internet.

Pictures leaked onto the Web of the purported lower-priced iPhone show an array of bright colors instead of just the same old black and white models available in recent years. That …

Current Limiting Coil Driver circuit Diagram

This is the Practical Current Limiting Coil Driver circuit Diagram. The p-channel devices are switched off by current sensors when the coil current reaches 10 A. The operation is similar to that of a switching-type power supply. The Schottky diodes and resistors are for spike protection.
Current Limiting Coil Driver circuit Diagram

Zener Diode Increase Regulator Output Circuit Diagram

A zener diode in the ground lead of a fixed pnp regulator varies the voltage output of that device without a significant sacrifice in regulation. The technique also allows the regulator to operate with output voltages beyond its rated limit.

Zener Diode Increase Regulator Output Circuit Diagram


Preregulator for Power Supply Circuit Diagram

This SCR pre-regulator keeps the filter capacitor Vc, in a variable output power supply, a few volts above the output voltage V0. The benefits include: less heat dissipated by the pass transistor and therefore small heatsink, cooler operation and higher efficiency, especially at low output voltages. Ql, Rl, R2, Dl and D2 form a constant current source for zener Zl, so that the contribution to the output current is always a few mA (2-3 mA). The Darlington pair Q2, Q3 keeps the SCR off.

Preregulator for Power Supply Circuit Diagram



The voltage Vc decreases until Vc = V0 = V at which point the Darlington pair fires the SCR, charging the filter capacitor to a higher voltage VC1 in less than half the period of the input voltage. The component values, shown are for a 0 - 250-V, 3-A power supply.


USB 3.0 Types

Three transistor audio amplifier

Switching inverter for 12v systems circuit diagram

This PWM control circuit provides the control pulse to the DMOS Power Switch in the flyback circuit. The output of the PWM is a pulse whose width is proportional to the input control voltage and whose repetition rate is determined by an external clock signal. 
To provide the control input to the PWM and to prevent the output voltage from soaring or sagging as the load changes the error amplifier and reference voltage complete the design. They act as the feedback loop in this control circuit much like that of a servo control system.

Switching inverter for 12v systems circuit diagram

Build a 5V Supply Circuit Diagram

This 5V Supply Circuit Diagram protects microprocessor systems from `brownouts` without the expense of an uninterpretable power supply. Designed around a small 9-V nickel cadmium battery the circuit continues to provide a constant 5-V output during brownouts of up to a few seconds. Load currents of up to 500 mA may be drawn using the components shown. 
With this mains-derived supply present, D5 is forward biased so that the stabilized supply powers the 5-V regulator and hence the circuitry to be protected. FET Tj is held on by Dl, its drain current being provided from the dc supply via Rb and D2. Diode D3 is reverse-biased so that T2 is off, and the battery is isolated from D6. RCH and D4 serve to trickle charge the battery with approximately 1.2 mA. 
 5V Supply Circuit Diagram


When the 12-V supply is removed, Rl and Cl initially keep Tl switched on. D3 is now forward biased, so that Tl drain current is drawn via Rb, D3 and T2 from the battery. This switches T2 on, allowing the load circ…