8 LEDs /w resistors for easy breadboarding

Front end protection for the Saleae logic analyser, allows up to +/-30V bipolar inputs.

Eight channels with series diode and resistor plus zener shunt to ground.

Board for clone of COT50 with master volume control.

Schematic: https://dl.dropboxusercontent.com/u/8021347/ChurchOfTone.png

A condensed version of the SAM4S Xplained board with onboard flash memory and a MicroSD slot, pinned out for SPI and I2C

MIC5205 from Micrel

Compact adjustable 1.5-5.5V switching regulator for N scale POV camera app.

Programmable PS/2-USB Converter

PIC18F4550

This board was designed to translate the non-standard IBM Model M 122-key Keyboard PS/2 scancode into the standard USB HID scancode.

120V / 12V 1.4A PSU 2014-02-21

For a project where off-the-shelf switching power supplies all had too much coil whine, I designed this linear power supply. It is noise-less, and runs silently. It is designed to be plugged into mains, with proper creepage/clearance zones, but you have to use a separate fuse in the power entry module for the grounded box you should mount this in.

Output voltage is set by the R2/R1 divider; the transformer and application I use set this at 12.0V.

If you’re not comfortable designing for and working with mains voltage electronics, I recommend against trying this project.

LiPo low-voltage cut-off 2014-03-24

After destroying a LiPo battery when forgetting to turn off a LiPo powered Raspberry Pi device, I built this circuit. It features a soft-power-on switch based on a P-channel MOSFET, and a space for an ATTiny85 to monitor voltage and turn off when it’s too low.

I have built this and use it, and I additionally talk to the ATTiny85 using the SPI in the Raspberry Pi (without chip select) to report voltage to the host, and do soft-power-off on demand.

Firmware for the ATTiny85 obviously is important for this project to work right!

20140420 P-channel Power Switch

This switch features pushbutton on and off action, as well as ability to actuate on and off through the 100-mil header. Power handling up to 20A, depending on specific P-channel MOSFET used and tolerance for board heat.

I have ordered, built, and tested this design, and it works well. Leakage current when off is below what I can measure – approximately equal to zero.

Revision A 2014-08-23

Surface Mount Breakout Board

Sound board for 444-310 by Chicago Dynamic Industries Pinball-Mods.com has the BOM and details on this board.

A small breakout board for the Maxim MAX31850K 1-wire type-K thermocouple amplifier with CJC. Project available on GitHub.

Provides an interface for connecting spark core to a RF remote using optocouplers

Interface to allow TRON Pro Pinbits/Eli Ramp mod to control ColorDMD, etc.

RF amplifier display board

http://g7ltt.blogspot.com/2014/08/20db-or-40db-rf-attenuator.html