Sunday, August 11, 2019
I have about 1000 circuits in a binder I started in 1982, most of them culled from magazines and books and most of them hand-drawn! The early circuits below were drawn using Protel Schematic and are just a sampling of what's available and what I've done. (I've built hundreds of circuits.)

In 2010, I scrapped most ideas using integrated circuits like CMOS, TTL  and 555 timers and graduated to  Microchip PIC MCUs (micro-controller unit) for new projects. Easier to write software than doing it in hardware.

I started using Arduino products in 2018 because they are so plentiful with tons of software available.   I'm also experimenting with other MCUs like Teensy3.2, ESP8266 and ESP32, Adafruit Trinket and XIAO chips.    Some of the circuits using these MCUs are on main Engineering page (page before this one).

Hover with mouse over a photo for description.

Flasher, 3 o/p out of phase with each other
4 outputs out of phase with each other, SCR control for AC
Motorola D5, 6809 development kit.
They wouldn't give me schematic so I reversed engineered it.
Atari 2600 mutli gamer
I"d read the Atari ROMS then duplicate them.
schematic for Bunzilla, bunny robot
CNC I built from plans on the Internet
counter, multi function
same counter, showing front
light sequencer, like Darth Vader helmet
My very first project, dual power supply
generic dual timer
converter to go from edge connector to pin header.
EMF detector.
For my "stereo room", controlled various things.
17 servo robot, made in 2017
MacIntosh emulator for a Radio Shack Color Computer
Matrix display test, found an old Coco perf board to use
Max232 converts serial out of PC to TTL for MPU
PIA tester
Nicad zapper
Occupancy detector for train layout.
Persistence of Vision project (POV)
POV Leds on board.
POV PCB layout
Prototyping board for PIC MCUs
Board for making sounds on railway
Rail sound controller for my train layout. Built (see left photo) but never used it.
simple 555 and maybe a decade counter to randomly flash ten outputs
Electronics for snowflakes (110V),  6809 computer at top, 3 triac boards at bottom.
8 channel triac board for Christmas Display or whatever...
Stepper motor controller using a PIC
Neon Wire sequencer
LIght flasher that simulates welding flashes
Port expander using 23017 I2C chip, PCB layout
Port expander schematic.  Used on snowflake and Star projects
PIC prototype board for 8 pin MCUs
Signal decoder to hardwire interface for Digitrax equipment on  train layout.   Never used.
Serial to parallel interface for printer
SFX Generator.  Was pretty cool.
SFX generator
SFX generator
Complete snowflake triac control for 110VAC bulbs
PIC 16F877 MPU to control the snowflake display.  4 triacs to select 1 or 3 snowflakes
16 channel triac controller board.
Adapter board (dongle) for snowflake simulator.  It worked, but I never used it.
Snowflake simulator adapter PCB.  Not sure what it did!
schematic of adapter.  I still don't know what it did.
snowflake simulator pre-adapter.
Static stimulus tester, single step through an MCU
Stepper driver
Strobe bar.  Planned to trigger 20-30 strobes inj sequence.
Strobe bar
Strobe bar
Thermostat control for heater that had none
Transistor tester, crude and simple but effective
Three 16 channel triac drivers
Ultrasonic Ranger.
Volt-Amp-Speedometer for Train Layout
Volt-Amp-Speedometer for Train Layout
voice IC used on Duncan robot
Project List 1977-2022