Vacuum Tubes Valves
Musical & effects
Yagi Uda Antennas
Metal Detector Circuits
Liquid Sensing Circuits
Light Sensing Circuits
Voltage Detector Circuits
Air-Gas Detection Circuits
Human Sensing Circuits
RF & Radiation
Optical Sensing Circuits
Free Energy Circuits
AC to DC & DC to DC
Solar Cell Circuits
Micro Power Circuits
Switching Power Supplies
Light Laser LED
Digital to Analog
Analog to Digital
Data Bus Circuits
Voltage to Pulse
Current to Voltage
Frequency to Voltage
RF Converter Circuits
Sine to Square Wave
Voltage to Current
voltage to frequency
Period to Voltage
Video Wall circuits
TV Video Circuits
Motor Control Circuits
8051 / 8052
PCB CAD Software
Car bike Circuits
555 Timer Circuits
Remote Control Toy
H Bridge Circuit
Interconnection & Timing
Digital Signal Integrity
Digital & Bipolars
Sensors & Detectors
Regulated Power Supply
4 Band Resistor
5 Band resistor
6 Band resistor
Human to Robotic Voice changer circuit
It is a simple and reliable system for processing human speech. It has the task of altering the tone of the human voice and making it heard as artificial, such as the voice of a robot that, as it is known, is produced by artificial means. This is an easy but reliable circuit that will solve many problems in cases where a voice needs to be...
Using two SCRs, this control circuit is designed to lock out the other SCR when one has been triggered, so only one lamp will light. Indicator lamp Il is controlled by SCRl. The operator simply presses switch Sl. Lamp I2 is similarly controlled by S2 and SCR2. With both switches open, neither lamp is lit. The result is insufficient gate...
Wheel Of Fortune
This circuit is a 10-LED spinning wheel that "clicks" as the wheel passes each point. The rotation starts fast, then gradu
Ultrasonic Bat reciever
You won't be disappointed with the performance of this sensitive ultrasonic receiver. It can let you listen to bugs, bats, engines, and virtually any other source of ultrasonic sounds. The circuit uses a piezo tweeter as an ultrasonic microphone, amplifier stages Ql, Q2, and an LO using a 567 IC. Q3 is a mixer that heterodynes the ultrasonic...
This circuit can be built small enough to frt inside a toy. The circuit consists of a relaxation oscillator utilizing one unijunction transistor (2N2646, MU10, TIS43). R2 and C2 determine the frequency of the tone. Pushing the button, SW1 charges up the capacitor and the potential at the junction of R2 and C2 rises, causing an upswing in the...
Toy police car circuit
Circuit works: VT1 is integrated infrared receiver, the red-emitting diode Xiao perimeter triode reception. IC1 (NE556) is a dual time base manifold by R5, R6, C5, composed of an oscillation circuit, the oscillation frequency is about 1 200 Hz, by 5 feet to
Toss-a-coin binary box
Circuit uses an astable multivibrator to vary the heads-or-tails condition, and a flip-flop to store the condition given by the multivibrator
Tape recorder 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). These impulses are lowered in amplitude and feed into the record input of a low cost tape...
Sounds from the IC IT82207
This circuit is able to take you to the world of the Wild West. For this it uses the integrated 18-pin IT82207 (IC1) of Holtek, which literally takes care of everything. You have to do is add a few accessories, including a loudspeaker and six selector switches.
Siren alarm simulates star trek red alert
The signal starts at a low frequency, rises for about 1.15 seconds to a high frequency, ceases for about 0.35 seconds, then starts rising again from a low frequency, and so on ad infinitum.
Simple Lie Detector Circuit
The circuit, uses a two-transistor direct-coupled oscillator that has a frequency determined by CI, R2, and the (skin) resistance across the touch pads. Since CI and R2 are fixed values, only the skin resistance across the touch pads can vary the sound of the oscillator. To sustain oscillations, CI feeds a portion of the output from Q2 back to...
Simple color organ
Transformer Tl can be any matching transistor type in the range of 500/500 to 2500/2500 ohms. No connections from the SCR or its components are connected to ground. For safety's sake, keep the 117-V line voltage from the amplifier connectionsâ€” that is the reason for using Tl. To adjust, set potentiometer Rl "off" and adjust the amplifier...
Ready set goi
This game tests a player"s reaction time. It is activated by closing switch SI, which starts the tone generator and arms the circuit. The touchplate, labeled PLAY in the diagram, consists of two metal strips about l/16th-inch apart. The first player to bridge the gap with his or her finger turns off the tone and lights the associated LED indicator
This circuit uses a timer to generate pulses at a 5-ms clock rate. The pulses are shifted into the shift register, one at a
Quiz Master Circuit
Up to eight players each have their own answer button to press, corresponding to the four Red Team and four Green Team LEDs on the master control board. As soon as the first contestant who thinks that he knows the answer presses the button, a loud tone sounds, all other contestants are locked out, and the contestant`s indicator LED lights on...
This circuit has a rate multiplier using a 4093 Schmitt trigger as an oscillator, driving a 4017 decade counter. When a pulse p
This is a circuit for a game of the shooting gallery variety. IC2a and b form an astable multivibrator clocking ICl which causes LEDs 1-8 to flash in turn LED 5 is the target LED and the object of the game is to depress PBI just as LED 5 comes on. If this is done, the whole display is blanked for a few seconds signifying a hit
Personal Message Recorder Circuit
The persona] message recorder is built around an ISD1016 CMOS voicc messaging system, which does away with the cumbersome and expensive analog-to-digital and digital-to-analog conversion circuits. A functional block diagram of the ISD1016 is shown. The ISD1016 contains all of the functions necessary for a complete message-storage system. The...
The two probes shown are held in the hands and the skin resistance applies bias to the transistor. The 5 k ohm pot is set for zero deflection on the meter. When the ' 'subject'' is embarrassed or lies, sweating on the hands takes place, increasing the bias to the transistor and upsetting the bridge balance.
LED Electronic roulette
Ul (a 4046 PLL containing a voltage controlled oscillator or VCO, two phase comparators, a source follower, and a Zener diode) is used to produce a low-frequency, pulsed output of about 40 Hz. The VCO's frequency range is determined by R6 and C2, which can be altered by varying the voltage at pin 9. The rising voltage causes the frequency to...
Game roller or chase circuit
The 555 timer produces a rapid series of pulses whenever switch SI is open. These pulses are counted in groups of 16 and converted into binary form by the 7493 and applied to the 74154 (a l-of-16 decoder/demultiplexer) wired so that each of its 16 output lines goes low sequentially and in step with the binary count delivered by the 7493. When...
Game feeder controller
The circuit is built around an LM339 quad comparator, Ul, which forms the basis of a Schmitt trigger, timer circuit, and a window comparator. One comparator within the LM339 (pins 1, 7, 6), plus LDR1, R4, R5, R6 and R8, is used as a Schmitt trigger. The timer circuit (which receives its input from the Schmitt trigger) consists of R9, RIO, Rll,...
The basic die circuit is given. A 555 timer, ICl, is connected as an astable multivibrator. This feeds clock pulses to divide-by-six counter IC2 tbe outputs of which are decoded by gates Nl to N6 to drive an array of LEDs in the familiar die pattern. When switch Sl is in position b, tbe reset input of IC1 decreases and the oscillator is...
Electronic Slot Machine Circuit
The slot machine`s realistic action is provided by seven ICs and three displays, as shown. Two 555 CMOS timer ICs generate pulses. IC1 is used to generate the clock pulses for the entire electronic slot machine. The pulses are coupled from the output (pin 3) to the clock inputs of IC4, IC5, and 1C6, the display-driver ICs. The displays are...
Electronic games schematic circuit
Today, we share a principle circuit of electronic games. The main circuit in accordance with the host through the IC2 reset press SB2, VD1A-VD9A not light. Prizes (for example 5) Which position by the number of people pointing Dot Award, the host closing the
Six LEDs are arranged to produce a display the same as the dots on a dice. When PBI is depressed, the display is blanked and the oscillator (ICl a, b, c) clocks IC2 at about 1MHz. IC2 counts from zero and resets on seven
Electromagnetic Ring Launcher Circuit
The electromagnetic ring launcher is comprised of.four subcircuits: a clock circuit (built around U5, a 555 oscillator/timer configured for astable operation), a count-down/display circuit (built around U3), a 74190 synchronous up/down counter with BCD outputs that is configured for countdown operation; U4, a ECG8368 BCD-to-7-segment...
Three lights are controlled by the three channels. One light will pulse in response to the bass, another illuminates with mid-range sounds, and the last lights for high notes. Four level controls allow adjustment of overall light level and each channel individually.
The circuit is basically a 555 astable circuit that divides two LEDs, LEDl and LED2. LED2 is switched on when the output of Ul is high, and LEDl is activated when its output is low. When Ul oscillates, LEDl and LED2 switch on alternately as the output of Ul switches from state to state. Resistor Rl"s value is high in comparison to R2, so...
Audio Memo Alert Circuit
This device prevents paper notes and memos from being overlooked. A paper note placed between two fingers made of a conducting material (metal or conductive plastic) breaks the circuit, allowing pair 1 of Ul-a to go high.
VCR Pong game
The most amazing thing about this project is the small number of parts. My boss joked that it involves 17 cents worth of parts and 1000 dollars worth of programming. But don`t worry -- the code is free to you! That means you can build this TV pong game in a very short time, or adapt the generic "video engine" portion of the program to make your...
USB IR Toy
Use a remote control with your computer, view infrared signals on a logic analyzer, or capture and replay remote control buttons. USB Infrared Toy v2 has an improved IR transmitter and several new features. There`s lots of interesting infrared projects on the web. Serial port infrared PC remote control decoders have been popular for years, Ian pub
555 Timer Circuits
RC Model Toy Circuits
H Bridge Circuits
255W Valve RF Transmitter circuit
This transmitter of 255W is depended on the coils we put at it to work in both the middle and the short waves. The power in the antenna is 255W and includes 4 states. The first consists of the EF80 that works as a COLLPITS CLAPP oscillator. Frequency selection is done in a somewhat unusual way: Instead of the variable capacitor, it uses a...
Arduino DAC Signal Generator project
Once the circuit gets current, all variables are initialized and the loop function is continually running. Initially all LEDs are off and there is no signal at the output. By pressing the signal switch, the first light that shows the most signal is at the output and the D0-D7 terminals give the appropriate signal which, when passing from the...
Recording circuit of phone conversations using PC
This circuit is used to record telephone conversations on your landline telephone. All you will need is this small circuit and subscription of your PC. There are few times when we forget what we said or told us. So we need recording. Sometime, not many years ago, recording of this kind of conversation was done with a small tape recorder. The...
FM Micro-Transmitter Bug Surveillance Circuit
The transmitter we recommend to build is quite simple. It can even be built by a beginner. However, unlike the ease of construction and its small size, it is almost certain that it will impress you with its outstanding performance. Its autonomy is 12-15 hours, with a 9 volt battery and its range is from 100 to 300 meters depending on the...
Construction of 50Watt 8Ω two-way Hi-Fi Speakers
The presented speakers are distinguished for their small dimensions and their extraordinary sound. Our home space is often limited and prohibitive for large speakers. This limitation does not mean that we will stay without high Sound Quality. Its design is simple, low cost and is easy to construct. Speaker types are too many and are designed in...
GSM modem circuit with Wavecom WMOi3
Modems are devices that connect either remote devices to a computer, or two or more computers to each other. Their connection is usually wired. The GSM modem we present is wireless. It can connect two computers, a computer with the internet or even be the central unit for a data acquisition system. Generally the construction is a GSM phone...
1W UHF Linear Amplifier with BLW33
This circuit is an amplifier for small transmitters operating in the UHF band, specifically in the 450-800MHz range. The amplifier works in class A and we used the well-known Philips BLW33 transistor for its manufacture. The construction, although simple, can be said to be quite critical due to the high frequency singularity. To achieve this, a...
8W Amplifier with TDA2003 circuit
Many times a small amplifier is needed to meet the needs of small spaces. This amplifier can be either mono or stereo, with this circuitry you can comfortably drive two small speakers. To build the amplifier you do not need anything but a few materials and a small power supply. The power of the amplifier, although low power, will solve many...
FM Linear Amplifier 400mW
This amplifier is intended for amplifying low signals from oscillators in the FM band. It does not have frequency regulators with variable capacitors and coils, it has a wide range and moderate power capable of driving several linear amplifiers. The whole construction is based on the two low-power 2N4427 transistors, which are designed for the...
Digital Signal Integrity
Interconnection and Timing of Digital Circuits
CMOS Circuits Tutorial
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