My Projects

       These are just some projects that I have done, some may have included schematics of the circuit used. I decided to publish them for the rare occasion that someone might find them useful or informative. Pages that link back to the old site are marked with a "**".

Tools and Measurement:

Micro Fly Cutter tiny fly cutter for my micro mill 15 Oct 2017
Arduino Multi Display Gauge Arduino based multi display gauge for turbo cars 14 Dec 2017
Cellphone Battery testing jig To insert cellphone batteries to my LiitoKala charger/tester 08 Apr 2017
My GPS Plaything Battery powered portable GPS receiver 15 Nov 2017
Portable current source Battery powered current source for testing LEDs and diodes 21 Oct 2016
Arduino Battery Metering Battery metering using an Arduino 23 Dec 2017
DIY SMD Tweezers A very sharp SMD tweezers for probing / testing 0402 size or even smaller parts. 08 Apr 2017
Component Tester and Jig Cheap multi component tester and a DIY test jig for SMD devices. 17 Oct 2015
4 Channel Dummy load 4x 100W dummy load for amplifier testing 31 Mar 2014
2 Stage Shift light Shift light with dual color LED indication 24 Mar 2014
PWM Fan speed controller Fan speed controllers for 4-wire fans 24 Feb 2014
Simple Frequency reference A simple frequency reference using a TCXO 31 Jan 2014
Rostock 3D Printer Pictures of a Rostock 3D Printer during assembly 04 Jan 2014
Amp Hour Meter Amp hour meter project without microcontrollers 25 Jan 2014
DIY Laser Power Meter Based on an Ophir 20C-A-1-Y OEM sensor head 15 Mar 2014
Micro Table saw Miniature table saw for cutting PCBs. (Update: New mini table saw with carbide tipped blades towards end ) 08 Oct 2015
Electronic pressure switch Electronic adjustable pressure switch for vehicle onboard air. 10 June 2012
PCB Drill Rig Rebuilt Variable speed precision PCB drill 13 Sep 2016
Mini Test Oscillator Built from ESP's P86 circuit and PCB 06 Nov 2011
PCB drill speed controller A drill speed controller I designed for 12V drills for PCB making 30 Jan 2011


Lithium Ion battery pack Making a big battery pack using 18650 cells 19 May 2017
12V 39Ah Solar Power Bank Portable power source for camping or emergencies. Uses an integrated 10W PV 26 Jul 2017
12V 45Ah Portable Power Bank Portable power source for camping or emergencies. Also charges from solar 03 Feb 2017
WindBoost Circuit to scavenge low wind output from your turbine 02 Dec 2014
Farm Off Grid system A project of mine. An off grid system for farm lighting. 15 Jul 2017
High current 12V Bench supply DIY bench supply using the common Dell server PSUs 06 Jan 2015
DC-DC converter DC-DC converter that can be configured for SEPIC or Boost topology. 04 Aug 2013
CC/CV Regulated Bench supply DIY constant voltage/constant current regulated supply based on LM317 datasheet 12 Jan 2014
Off Grid Power System Renewable energy system used at home 14 Dec 2017
Discrete Lithium Ion Charger

DIY Lithium Ion/Polymer Charger without specialized IC's 23 Apr 2011
SMPS Project ** Scalable switch mode supply for car audio 2004


LED conversion Converting a 120VAC lamp to 12V operation 17 Oct 2015
1200 lumen LED Rear Foglamp My surprise to tailgaters 21 Apr 2013
DIY HID Flashlight HID flashlight made from cheapie Chinese flashlight 06 Nov 2011
HID LED Bike Light My bicycle lighting, accessories and mods blog 05 Jul 2017


Hypex UcD car amplifier Building a car amp using UcD180HG modules 09 Feb 2014
High Power P101 home amp A Hifi amp I built using ESP P101 Boards. (large page) 22 July 2012
Phone Horn Make your Phone speaker louder without batteries! 15 Jan 2012
PWK designed Sub Enclosure My latest car sub stage custom designed by PWK Designs 09 Nov 2011
Mini Test Oscillator Made a custom acrylic case for ESP's P86 Test oscillator 06 Nov 2011
DIY RTA Building an RTA from scratch (large page) 05 Mar 2013
Car subwoofer box ** Build log of my car subwoofer system 30 Mar 2011
2 Way crossover with chip amp ** Small 2-way 2nd Order LR with 4ch chip amp for multimedia speakers 21 Feb 2011
Vented full range PC speaker ** My speaker build for my laptop 23 Feb 2011
DIY High end Line Driver A high end line driver I designed and built for a car audio shop 23 Jan 2011
4 Channel Mic preamp with mixer ** DIY 4 input Mic preamp with mixer 2004
5 Channel mixer ** DIY 5 input line level mixer 2004
5 way Linkwitz Riley Crossover ** DIY Linkwitz Riley crossover for a multi amp sound system 2004

Page created and copyright R.Quan © 2004.