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Showing posts from February, 2014

Simple Tape Recorder Interface Circuit Diagram

This is a Simple Tape Recorder Interface Circuit Diagram. However, you can record cassette tapes into any of these machines with an audio interface. The interface allows data to be saved on an ordinary tape recorder at a speed of 2400 bit/s. The serial stream of data Fig. 1 (A) is coded with a clock of 2400 Hz (B), by means of XOR gate IC 1/1. Logical `high` and `low` appear as shown in Fig. 2 (C). 
Simple Tape Recorder Interface Circuit Diagram


These impulses are lowered in amplitude and feed into the record input of a low cost tape recorder. During the playback, pulses (D) are amplified with CMOS gate IC 1/2 connected as a linear amplifier, and providing a TTL level signal shown in (E). On both positive and negative transitions IC 1/4 forms short pulses as shown in (F) (approx. 50 *ts) that triggers one shot IC2. A monostable one shot pulse width is adjusted to be 3A of bit length (310 µß). 
A change from `high` to `low` in a coded stream generates a `low` pulse width of one bit cell…

Simple SGI Amplifier Circuit Diagram

This is a Simple SGI or Strain Gauge (Gage) Instrumentation Amplifier Circuit Diagram.This circuit has an overall gain of 320. More gain can easily be obtained by lowering the value of R2. Untrimmed Vas is 10 11V. and Vas tempco is less· than O.lJIV/°C. In many circuits, the OP07 can be omitted, with the two MAX421 differential outputs connected directly to the differential inputs of an integrating a /d.
Simple SGI Amplifier Circuit Diagram

Digital Composite op Amplifier Circuit Diagram

Build a Digital Composite op Amplifier Circuit Diagram. In the most general sense of the word, any additional circuitry at either the input or the output of an amplifies. A composite configuration greatly reduces de errors without compromising the high-speed, wide band characteristics of HA-2539. The HA-2540 could also be used, but with slightly lower speeds and bandwidth response. 
 Digital Composite op Amplifier Circuit Diagram


The HA-2539 amplifies signals above 40 kHz which are fed forward via C2; R2 and R5 set the voltage gain at -10. The slew rate of this circuit was measured at 350 V /p.s. Settling time to a 0.1 % level for a 10-V output step is under 150 ns and the gain bandwidth product is 300 MHz. The HA-5170 amplifies signals below 40kHz, as set by C1 and R1, and controls the de input characteristics such as offset voltage, drift, and bias currents of the composite amplifier
Therefore, it has an offset voltage ofl00 p.V, drift of 2 p.V/°C, and bias currents in the 20-pA ran…

Simple Electronic Light Sequencer Circuit Diagram

This is Simple Electronic Light Sequencer Circuit Diagram. The light sequencer uses two ICs and 10 SCRs to create.an ac sequencer. The first 10, a 555 timer, is used to provide clock pulses for 102. The 10 is configured as an astable multivibrator, and its output is on pin 3. 
Capacitors CI and 04, along with resistor R2 and potentiometer PI, control the frequency of the pulses. IC2 is a 4017 Johnson counter, which shifts a high-signal level to each one of its 10 output pins in sequence. Each output pin is resistively coupled to the gate lead an an SCR. When the respective output pin on the 4017 is high and the positive half of the ac cycle is on the anode lead of the SCR, it turns on.
Electronic Light Sequencer Circuit Diagram With Parts List


The lamp that is connected to its anode lights. Power is brought into the PC board by the line cord, then the circuit is fuse-protected. Diode LD1 changes the ac to pulsating, which is smoothed by C2 and C3. R23 limits the current, and zener diode…

Build a Buffer Amplifiers Circuit Diagrams

How to build a buffer amplifiers circuit diagrams. A buffer amplifier is one that provides electrical impedance transformation from one circuit to another. These two buffer/amplifiers that have been successfully used with VFOs: one (shown in A) is based on a pair of bipolar npn transistors, and the other (shown in B) is built around a dual-gate MOSFET.
Buffer Amplifiers Circuit Diagrams

Digital H-V AC Switcher Circuit Diagram

This is a digital H-V or high voltage AC switcher circuit diagram, Switching a high voltage AC requires use of opto couplers to isolate the High Voltage from the micro controller. A basic circuit to trigger an SCR is shown in Fig. 67 -lA. This circuit has the disadvantage that the blocking voltage of the photon-coupler output device determines the circuit-blocking voltage, irrespective of higher main SCR capability. Adding capacitor Cl to the circuit, as shown in Fig. 67-lB, will reduce the dV!dt seen by the photoncoupler output device.

 Digital H-V AC Switcher Circuit Diagram

Click right and Save image and zoom for best view The energy stored in Cl, when discharged into the gate of SCRl, will improve the dildt capability of the main SCR. Using a separate power supply for the coupler adds flexibility to the trigger circuit; it removes the limitation of the blocking voltage capability of the photon-coupler output device. The flexibility adds cost and more than one power supply might be ne…

One IC Based One Chip Chime Circuit Diagram

Build a One IC Based One Chip Chime Circuit Diagram. This circuit uses only one IC, produces a pleasant tone, and sports a single control for adjusting the tone`s chiming rate. IC1A and IC1B form an astable multivibrator, which produces the circuit`s basic tone.
 One IC Based One Chip Chime Circuit Diagram The multivibrator`s frequency is: The component values produce a 668-Hz tone. IC1C buffers the multivibrator`s output to the 8- speaker. Current-limiting resistor R2, determines the speaker`s volume. R2 minimum value is 220 . IC1D and IC1E form an asymmetric, astable multivibrator, which adds a chime effect to the circuit`s basic tone. 
The chime effect`s frequency is: R7 gives this rate multivibrator a slowly varying output signal to produce a pleasant decay for the chime effect. IC1F is an inverting amplifier for the chime multivibrator.

Electronic Solid State Stepping Switch Circuit Diagram

This is a simple Electronic Solid State Stepping Switch Circuit Diagram. Solid is one of the four fundamental states of matter. It is characterized by structural rigidity and resistance to changes of shape or volume. In electrical controls, a stepping switch , also known as a stepping relay, is an electromechanical device which allows an input connection to be connected to one of a number of possible output connections, under the control of a series of electrical pulses. 
Electronic Solid State Stepping Switch Circuit Diagram

This circuit was designed to make switching of a 48-channel mobile transceiver safe to operate while mobile. The oscillators allow for single-stepping or a scanning function. The scan facility allows for stepping through all 48 channels to check for occupancy or otherwise, and each output is indicated with an LED and labeled accordingly, so at-a-glance indication is possible.With full scope of this circuit it is possible to scan 256 channels and by adding more 4 …

Electronic Touch On Switch Circuit Diagram

This is a simple Electronic Touch On Switch Circuit Diagram. The Touch Switch circuit will detect stray voltages produced by mains voltages and electrostatic build-up in a room. This touch on-only switch can be triggered into conduction by electrical means, and can only be reset by way of a mechanical switch. When the touch terminal is contacted by a finger, the SCR turns on and illuminates LED1.
Electronic Touch On Switch Circuit Diagram



Simple 2 Door Annunciator Circuit Diagram

Security system or alarms such as doorbell and Door Annunciator are most wanted in industries and institutional use. This is a Simple 2 Door Annunciator Circuit Diagram. When the push buttons at either door are depressed, this circuit generates a different tone for each door. Tones are generated by phase-shift oscillator Q1/Q2. Q3 provides tone frequency change by changing the phase-shift network. U2 and U3 are timers for the tones and Q4/Q5 interface the timers with the push buttons. 
Simple 2 Door Annunciator Circuit Diagram

Simple WBA Amplifier Circuit Diagram

This is a simple (WBA) wide band agc amplifier circuit diagram. In this circuit The NE592 is connected in conjunction with a MC1496 balanced modulator to form an excellent automatic gain control system. The signal is fed to the signal input of the MC1496 and re-coupled to the NE592. Unbalancing the carrier input of the MC1496 causes the signal to pass through unattenuated. Rectifying and filtering one of the NE592 outputs produces a de signal which is proportional to the ac signal amplitude. After filtering, this control signal is applied to the MC1496, causing its gain to change. 
Simple WBA Amplifier Circuit Diagram


Build a Schmitt Trigger Circuit Diagram

This is a simple Schmitt Trigger Circuit Diagram. Schmitt trigger is a comparator circuit with hysteresis, implemented by applying positive feedback to the non inverting input of a comparator or differential amplifier. It is an active circuit which converts an analog input signal to a digital output signal. In this circuit A 555 IC is shown configured to function as a Schmitt trigger. Inputs above and below the threshold level will turn the circuit on and off producing a square wave output. 
Schmitt Trigger Circuit Diagram

Digital Electronic Door Buzzer Circuit Diagram

This is a simple Digital Electronic Door Buzzer Circuit Diagram. Affordable simple door buzzers and buzzer systems for door entry security in homes, offices and buildings. When SI is depressed, an initial positive voltage is placed on C2 and the noninverting terminal of Ul. The circuit oscillates at a low frequency. As C2 charges up through R3, a rapid increase in frequency of oscillation results, producing (at SPKR1) a rapidly rising pitched sound. This sound is easily recognized over ambient noise. 
Digital Electronic Door Buzzer Circuit Diagram

Digital Optical TTL Coupler Circuit Diagram

Digital Optical TTL Coupler Circuit Diagram. TTL converter options for underwater photography, TTL converters and strobes that support optical TTL. For higher speed applications, up to 1-MHz NRZ, the Schmitt-trigger output HllL series optoisolator provides many features. The 1.6-mA drive current allows fan-in circuitry to drive the IRED, while the 5-V, 270-0 sink capability and lOOns transition times of the output add to the logic coupliug flexibility. 
Digital Optical TTL Coupler Circuit Diagram

Input Minimum Maximum Selector Circuit Diagram

This is a simple Input Minimum Maximum Selector Circuit Diagram. This circuit outputs the maximum (or the minimum) of the four input voltages Vv V2, V3, and V4. Each of these input voltages is in the range 0 to 5 V. The output of the unit is the maximum of Vv V2, V3, and V4 if the control voltage input is 5 V (i.e., logical 1). The output is the minimum of Vv V2, V3, and V4 if the control input is zero. By cascading TV such units, one can select the maximum (or the minimum) of 3N + 1 input voltages. Thus if k is the number of input voltages, we need [(/c+l)/3] units.
Input Minimum Maximum Selector Circuit Diagram


Capacitance Operated Battery Powered Light Circuit Diagram

Build a simple Capacitance Operated Battery Powered Light Circuit Diagram. Capacitance is the ability of a body to store an electrical charge. Any object that can be electrically charged exhibits capacitance. A common form of energy storage device is a parallel-plate capacitor. Touch the plate and the light will go on and constant of the 47 µf capacitor and the 2M remain on for a time determined by the time resistor.
Capacitance Operated Battery Powered Light Circuit Diagram

Simple Sound Activated Tape Switch Circuit Diagram

This is a Simple Sound Activated Tape Switch Circuit Diagram. This circuit can cause a cassette recorder to automatically tum on and record when a sound or noise is present. Another use, is when the sound-activated switch is used to tum on a cassette player so that it operates as a burglar-alarm detector and sounder. Op amps Ula and Ulb are connected in tandem to amplify the sounds picked up by the detector`s mike. 
The amplified audio voltage, output at pin 7 of Ulb, is fed to a voltage`doubler circuit, consisting of Dl and D2. The elevated voltage from the doubler circuit is input to the positive input of op amp Ulc, which is operating as a simple comparator circuit.Sound-activated-tape-switch The other input of Ulc is connected to a voltage divider that sets the switching point for the de signal voltage, to turn on when the signal level is greater than about 1.5 V. As the comparator switches on, its output at pin 8 becomes positive and supplies a forward bias to tum on D3 and Ql, wh…

Build a Differential Instrumentation Amplifier Circuit Diagram

Build a Differential Instrumentation Amplifier Circuit Diagram. An instrumentation amplifier is a type of differential amplifier that has been outfitted with input buffer amplifiers, which eliminate the need for input impedance matching and thus make the amplifier particularly suitable for use in measurement and test equipment.This circuit relies on extremely high input impedance for effective operation. The HA-5180 with its JFET input stage, performs well as a preamplifier. 
 Differential Instrumentation Amplifier Circuit Diagram


The standard three amplifier configuration is used with very close matching of the resistor ratios R5/R4 and (R7 + R8)/R6, to insure high common-mode rejection (CMR). The gain is controlled through R3 and is equal to 2RI/R3. Additional gain can be had by increasing the ratios R5!R4 and (R7 + R8)!R6. The capacitors C1 and C2 improve the ac response by limiting the effects of transients and noise. 
Two suggested values are given for maximum transient suppression …

Simple Electronic Coin Tosser Circuit Diagram

This is a Simple Electronic Coin Tosser Circuit Diagram. For this project, you create an electronic version of a coin toss. Instead of flipping a coin into the air to see if it lands heads or tails, you build an electronic.The circuit shown simulates the flipping of a coin by merely pushing switch PB1. This is an easy circuit.
Simple Electronic Coin Tosser Circuit Diagram


Simple Diode Feedback Comparator Circuit Diagram

This is a Simple Diode Feedback Comparator Circuit Diagram. This circuit can drive an LED display with constant current independently of wide power supply voltage changes. It can operate with a power supply range of at least 4V to 30V. With 10M resistances for R2 and R3 and the inverting input of the comparator grounded, the circuit becomes an LED driver with very high input impedance. The circuit can also be used in many other applications where a controllable constant current source is needed.
Diode Feedback Comparator Circuit Diagram


Wide band Instrumentation Amplifier Circuit Diagram

This is a simple Wide band Instrumentation Amplifier Circuit Diagram. A high performance, wide band instrumentation amplifier includes a main differential amplifier channel which receives an input signal having both differential . Has an input resistance of 1-MO, a bandwidth from de to about 35 MHz, and a gain of 10 times. 
 Wide band Instrumentation Amplifier Circuit Diagram


Low frequency gain is provided by a CA3130 BiMOS op amp operated as a single-supply amplifier. High-frequency gain is provided by a 40673 dual-gate MOSFET. The entire amplifier is nulled by shorting the input to ground and adjusting R9 for zero de output voltage.

Comparator with Variable Hysteresis Circuit Diagram

This is a simple Comparator with Variable Hysteresis Circuit Diagram.Variable Hysteresis  is a Band Current Controller for Power. An operational amplifier can be used as a convenient device for analog comparator applications that require two different trip points. 
 Comparator with Variable Hysteresis Circuit Diagram

 The addition of a positiver feedback network introduces a precise variable hysteresis into the usual comparator switching action. Such feedback develops two comparator trip points centered about the initial trip point or reference point The voltage difference, AV, between the trip points can be adjusted by varying resistor R2. When the output voltage is taken from the zener diode, as shown, it switches between zero and Vz, the zener voltage.

Simple Dc Static Switch Circuit Diagram

This is a Simple Dc Static Switch Circuit Diagram. This circuit is a static SCR switch for use in a dc circuit. When a low power signal is applied to the gate of SCR1, this SCR is triggered and voltage is applied to the load. The right hand plate of C charges positively with respect to the left hand plate through Rl. 
 Simple Dc Static Switch Circuit Diagram


When SCR2 is triggered on, capacitor C is connected across SCR1, so that this SCR is momentarily reverse biased between anode and cathode. This reverse voltage turns SCR1 off provided the gate signal is not applied simultaneously to both gates. The current through the load will decrease to zero in an exponential fashion as C becomes charged.

The Final Cell Phone Jammer Circuit Project

After having huge requested of Johnson John, Jishnu Np, aswinth raj and others. we are going to start dual band mobilejammer for GSM 900 and GSM 1800 done by Ahmed Sudqi Hussein, Abdul-Rahman, Ahmad Nasr and Raja Mohammad. This project is not based on voilation it is a project through it, student and hobiyists can get many benfit for thier social and acadmic life.
1. Introduction Communication jamming devices were first developed and used by military. This interest comes from the fundamental objective of denying the successful transport of information from the sender (tactical commanders) to the receiver (the army personnel), and vice-versa. Nowadays, mobile (or cell) phones are becoming essential tools in our daily life. Here in Jordan, for example, with a rather low population (around 5 million), three main cell phone carries are available; namely; Zain, Orange, and Umniah  
The first two use the GSM 900 system, while the third uses the GSM 1800 system. Needless to say, the wide use of…

Simple Sound Generator Circuit Diagram

This is a simple Run-Down Clock or Sound Generator circuit diagram. Used in electronic roulette or dice games, this circuit produces a clock signal that initially is several tens of kHz (depending on C2) and gradually decreases to zero in about 15 seconds, as CI discharges through R4.
Simple Sound Generator Circuit Diagram

Pseudo Random Bit Sequence Generator Circuit Diagram

This is a simple Pseudo Random Bit Sequence Generator Circuit Diagram. A binary sequence is a sequence of bits, i.e. A BS consists of ones and zeros.In this circuit, an additional exclusive-OR gate is connected after the modulo-2 feedback, with CI and R2 applying the supply turn-on ramp into the feedback loop. 
 Pseudo Random Bit Sequence Generator Circuit Diagram



This provides sufficient transient signal so that the PRBS generator can self-start a power-up. A shift-register length of 10 is shown with feedback at stages 3 and 10, providing true and inverted maximal length sequence outputs. This technique applies an input directly to the feedback loop.
Therefore, it`s considered more reliable than applying an RC configuration to the shift-register reset input to create a random turn-on state.