Game Circuits

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 frequency of oscillation...

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..

Electronic Dice

When SI is pressed, counter U2 is driven by oscillator U1A/U1B and the count (0 through 6) is read on DISP1. Rl and CI dete..

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 common-cathode 7-segment LED types. They are wired to display three different symbols, an L, a 7, and bar, When all three displays.....

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..

Color organ

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. ..

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 latch/decoder/display driver; and DISP1, a common-cathode seven-segment display), a trigger circuit (comprised of U6), an MOC3010.....

Reaction Timer

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 ..

Electronic dice

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..

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 rise from zero to threshold and remain at that frequency as long as SI is closed. When SI is opened, Cl discharges slowly through Rl.....

Pot shot

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..

heads or tails

SI must be a push-to-make, release-to-break, switch..

Run-Down Clock/Sound Generator

Used in electronic roulette or dice games, this circuit produces a clock signal that initially is several te..

Electronic coin tosser

The circuit shown simulates the flipping of a coin by merely pushing switch PB1..

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 recorder. During the playback, pulses (D) are amplified with CMOS gate IC 1/2 connected as a linear amplifier, and providing a TTL.....

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 the control board so that it`s obvious who buzzed in first. The control board also features two selectable time out periodseach.....

4-Channel commutator

The DS7800 voltage translator is a monolithic device that provides from 10 V to -20 V gate drive to the JFETs while at the same time providing DTL/TTL logic compatibility. ..

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. ..

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 preamplifier stage accepts audio signals directly from an external microphone and routes the signals to the OUT (analog out).....

Electronic keyer

This circuit automatically produces Morse code dots and dashes set by time constants involving Cl and C2. Rl sets dot/dash ratio and R2 sets the speed..