"To invent, you need a good imagination and a pile of junk." - Thomas A. Edison
PCBs and kits available for sale based on some electronic projects here can be found at Catahoula Technologies.
An electromechanical 4-digit nixie clock with a IN-13 seconds indicator.
A 4-digit nixie clock using CD72 nixies and relay counting logic on a PCB.
A single digit nixie clock controlled by a PIC 16F84A. Two designs are included here for a standard 10-cathode nixie and another for a B7971 alphanumeric nixie.
My first nixie clock using four Burroughs B-5560 nixies and 10 ICs.
Improved 4-digit nixie clock using Russian IN-17 nixies and 8 ICs.
A 4-digit nixie clock using large B7971 alphanumeric nixies and 10 ICs.
A 6-digit nixie clock using National NL-8423 nixies and a PIC 16F628.
World's Second Nixie Propeller Clock
A single digit nixie propeller clock that displays 6-digit time.
Clocks that use a microcontroller and a DAC to draw a clock face on an oscilloscope CRT.
Persistence of Vision Propeller Clocks
Mechanically scanned persistence of vision digital clock or message board using a microcontroller and a spinning array of LEDs.
Single Meter Clocks
Clocks that use an analog meter to tell the time.
Single Numitron Clock
A miniature digital clock using a numitron tube to tell the time.
Single VFD Clock
A miniature digital clock using a vacuum fluorescent display tube to tell the time.
Analog Oscilloscope Pong
Two designs for a traditional or round screen Pong game on an oscilloscope.
Analog TV Pong Game
A pong game that uses 13 discrete chips and generates RF output to a TV.
A single player pong-like game using a 8x9 LED matrix and a mixed analog and digital design with discrete components.
A TV Pong game using the GI AY-3-8500-1 IC stuffed in an era-appropriate Sony FD-40A WatchMan TV.
Smallest CRT Tetris Arcade Machine?
A tiny Tetris arcade machine using a PIC 16F84A and a miniature CRT camera viewfinder.
A Noisy High Voltage Generator
How to build a simple electromechanical relay-driven high voltage generator that runs off low voltage or batteries.
Solid-state and tube designs for TV flyback drivers.
How to make a fun and simple device to generate a high voltage rising arc.
A high voltage generator that creates big sparks from charging capacitors in parallel and dischargeing them in series.
Solid State - Medium Coil
A medium sized SSTC using a half-bridge driver design and generates up to 6 inch long discharges.
Spark Gap - Large Coil
A large spark-gap based Tesla coil that stands about 5 feet tall and generates up to 3 feet long discharges.
Spark Gap - Medium Coil
A medium sized spark-gap based tabletop Tesla coil that stands about 2 feet tall and generates up to 1 foot long discharges.
Spark Gap - Small Coil
A small spark-gap based tabletop Tesla coil using an old bug zapper transformer and generates up to 2 inch long discharges.
Vacuum Tube - Small Coil 1
A small VTTC using a 5Y3 and 6146 tube that generates one-quarter inch long discharges.
Vacuum Tube - Small Coil 2
A medium sized VTTC using a 4x150 and generates half-inch long discharges.
Digital 0-150VAC Voltmeter
A two and half digit AC voltmeter using common TTL and CMOS components for measuring AC voltage from a variac.
A basic 4-bit binary adder with basic register storage made entirely out of relays.
Learn all about how to design digital logic circuits with electromechanical relays.
A larger CPU made entirely out of over 280 relays.
Various interesting schematics and pictures of experimental projects are often stored in this folder so check them out if you are adventurous.
Tool Magnetizer and Demagnetizer
A simple project with low parts count for quickly magnetizing or demagnetizing screwdrivers.
Convert from composite NTSC video to X, Y, and Z signals for an oscilloscope to become a video monitor.
Build your own simple electrostatic CRT oscilloscope based on solid-state or tube designs.
Convert from computer VGA video to X, Y, and Z signals for an oscilloscope to become a computer monitor.
A spinner using a neon-filled Dekatron tube running off 120V mains.
An Altoids-based audio amplifier using a 6LU8 compactron tube.
An all-tube strobe using the vintage 631-P1 neon strobotron tube.
Subminiature Tube Superheterodyne Radio
A 5-tube superhet radio using subminiature tubes.
TV Tube Regenerative Radio
A regenerative radio receiver using a couple "worthless" TV tubes.
Two-tube AM Transmitter
Build a two-tube AM transmitter from one of two designs including all-tube or a hybrid mixing some solid-state with tube technology.
Voltage Regulator Tube Nightlight
Great and useful circuit to light up a hallway with the warm glow of neon at night.
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