3 Input First Response Monitor:  (schematic / circuit added 11/03)

32 Kb x 8 emulator for the GameBoy:  (circuit / schematic design added 2/07)

A real yoyo project:  The original yoyo was equiped with 2 LEDs that lit up when  device was spinning. I decided to add a micro to give it some extra pazazz.
The trick here is to make  unit work without a power switch. The mercury switch is positioned so that it supplies power when  unit is spinning. After about 20 seconds,  PIC shuts down in sleep modes, see listing below. That way, if  switch is still on when  device is put away,  power can never be stuck in  'on' mode....  (electronic design added 10/06)

Archery Timer:  (circuit / schematic added 6/05)

Battery Meter for Pinball Machines:  (electronic circuit added 04/05)

Bingo!!! (On Your TV):  (electronic circuit added 9/05)

Burger Time Arcade Game:  (electronic circuit added 04/05)

Circuit Improves Further on First Event Detector:  06/27/02 EDN Design Ideas  / (added 2/05)  The circuits in Figure 1have certain advantages over those in a previous Design Idea (Reference 1). The first-event detector with autoreset (Figure 1a) consists of N sets of monostable multivibrators, using 4001 logic circuits with LEDs attached. After any player (1 through N) presses a pushbutton, the corresponding monostable multivibrator switches on, and its associated LED lights.

Circuit Improves on First Event Detection:  08/16/01 EDN Design Ideas  /  (added 1/05)  The circuits in Figure 1 and Figure 2 exhibit certain advantages over the circuit shown in the Design Idea in EDN , "Circuit detects first event," May 3, 2001 EDN Design Ideas  /  (added 1/05), pg 89. The n-player first-event-detection circuit offers several improvements: It has fewer passive components. It needs only n diodes instead of (n2+n)/2 for three or more players....

Coin Tosser:  The UJT transistor Q1 can be replaced with a NTE6409 or ECG6409.  At the press of S1 the oscillator starts and runs the clock on pin 14 of the CD4017 decade counter at a time determined by R1 and C1.  During that time both LED's will flash back and forth until the oscillator stops and either the red or green led will be lit.  The values shown are for working with 9 volts and none of the parts are critical.  (added 2/06)

Combinational Conjuring Trick (citcuitdb):  The simple circuit of Fig.1 emulates a similar conjuring trick which sells for hundreds of Pounds. The trick seems to do the almost-impossible from an electronic point of view, let alone from the.... (added 2/07)

Combinational Conjuring Trick:  (schematic / circuit design added 9/02)

Conjuring Trick:  (schematic / circuit design added 9/02)

Connecting Sega 3d Glasses to a PC Serial Port:  (electronic schematic added 703)

Dig Dug Arcade Game:  (electronic circuit added 04/05)

DIT shutterglasses controller:  (circuit added 2/07)

Dreamcast interface:  (schematic / circuit added 2/07)

Dreamcast PC serial adapter:  (schematic / circuit added 2/07)

E.S.P. Conjuring Trick (circuitdb):  A former President of the Magic Circle, three times awarded the International Award for Magic, commented when he saw this trick: "Absolutely incredible!" It might be of interest to conjurers that.... (added 2/07)

E.S.P. Conjuring Trick:  The design uses tactile sense (or rather, neural sense) to reveal the contents of a box. The box contains 4 shapes, as in a child's shape sorter. The conjurer asks a person to secretly remove from the box any shape or shapes of his or her choosing, then to close the box, and to place a silk over it. The conjurer then rests a hand on the silk, and through "extra-sensory powers" reveals the contents of the box..... (electronic circuit added 4/05)

Electronic Dice (electronickits):  (schematic added 10/06)

Electronic Jam:  (electronic Circuit / Schematic added 10/04)

Electronic Nicad glow plug driver:  (diagram added 2/07)

Electronic Roulette Wheel:  A novel circuit that duplicates the function of a 10-slot Casino-style Roulette Wheel. Features a "coast-down" clock generator, to add realism.  (circuit design added 7/06)

Electronic Scoring Game #2:  (electronic Circuit / Schematic added 10/04)

Electronic Scoring Game:  (electronic circuit added 10/05)

Evil Genius: Resistor Attack Game :  The 'resistor attack game' is a fun variant of the space invaders game designed to help you learn the resistor colour code. This game has been donated to us by Mr Cutcher who has written the book Electronic Circuits for the Evil Genius. (added 2/06)