Please Note:
Over time this update page has grown quite long. To make it more manageable, I have archived older work in the links below.

Archive 2001-2002

Archive 2003-2004

Archive 2005-2006

Archive 2007-2008

IR Switch Page and diagram updated 30-1-09
DC Reversing Circuit Updated 31-1-09
Solid State Reversing Circuit Updated 31-1-09
Schematics Page redesigned 18-2-09
Timing Circuits Page redesigned 19-2-09
Monostable Timer Updated 19-2-09
All main menus and sections updated 21-2-09
LTspice New page added in Simulator section 21-2-09
LF Oscillator 21-2-09
Predicting Thermistor Resistance by Ron J in Analysis Section 23-3-09
Downloadable Thermistor Resistance Charts (bottom of page) by Ron J 23-2-09
Repeating Interval Timer New Vero Layout by Ron J 23-2-09
Toggle Switch No.1 by Ron J 23-2-09
1 Hour Timer 23-2-09
Thermostat with Adjustable Hysteresis by Ron J 23-2-09
Analysis and Design Page Updated 27-2-09
Schematic sections, Alarm, Audio, Timing , Switching Updated 7-3-09
Section RF and Power Circuits Updated 14-3-09
All Schematic sections, Miscellaneous, Control and Interface, Testgear now updated 23-3-09
Computer Virus Removal added to Media Section 27-3-09
EMF Probe Version 2 27-3-09
Solar Flasher by QS 27-3-09
Credits Page, Disclaimer and Viewers Gallery moved to Help Page 6-4-09
LF071 Mic Amplifier new text added 6-4-09
AM Receiver new text added 6-4-09
Links Page Updated 22-5-09
Toggle Switch No. 2 by Ron J 23-5-09
Sequential Timer by Ron J 23-5-09
Temperature Alarm Circuit modified 30-6-09
IC Pinouts Updated 14-6-09
6 Input Mixer Updated 15-7-09
Reduction of Detector Diode Losses in a Crystal Radio(Theory section) by Ramon Vargas 15-7-09
Optimization of the Signal Voltage of a Selectivity Enhanced Germanium Detector ( PDF Format) by Ramon Vargas 15-7-09
Links Updated 5-9-09
Aerial Tuning Unit page updated 14-9-09
Latch Switch Added14-0-09
Resonant Circuits Updated 14-9-09
DX-ing and SW Link added to Media Section 14-9-09
Op-amp Astable Timer 14-9-09
AM Receiver Updated special thanks to David from Germany for his coil pictures 14-9-09
Circuit Images Gallery Updated 16-9-09
AC Switch circuit Added 16-9-09
SW Receiver Circuit Mod and Page Updated by Ramon Vargas 17-9-09
Download Page Updated 10-10-09
Winscope article Updated 19-10-09
Ron J's Circuit Pages now hosted on Circuit Exchange 27-11-09
2 Zone Intruder Alarm by Ron J 27-11-09
Field Strength Meter for 2.4Ghz by John Samnin (external link) 27-11-09
Medium Wave DX Receiver external link to Duncan's in New Zealand 27-11-09
Increasing Regulator Current Page Updated 2-1-10
Links Updated 2-1-10
Mini Metronome Added 4-1-10
Colour Organ Added 4-1-10
136 KHz Receiver Added
40m Superhet Receiver Circuit added (external link) 4-1-10
Ohms Law for AC Circuits updated 5-1-10
Download Page updated 6-1-10
Guitar Fuzz Effect added (external link) 12-1-10
Guitar Reverb Circuit added (external link) 12-1-10
Theremin Circuit added (external link) 12-1-10
3 Zone Duress Alarm 12-1-10
Multiple Output DC Converter 12-1-10
Home Made PCB's two new links in the Practical Section 12-1-10
L200 Power Supply Page Updated 20-1-10
2 Watt Amplifier Page updated 21-1-10
32 Watt Stereo Amplifier 29-1-10
12 Volt 20 Amp Power Supply 29-1-10
Long Range FM Transmitter by Viswanathan Prakash 29-1-10
AM Transmitter Page Updated 29-1-10
Tuned Circuit Page updated 29-1-10
AM Receiver PCB board uploaded 30-1-10
Simulation Page Updated 1-2-10
6 Zone Alarm Schematic updated 4-2-10
Power Failure Alarm 8-2-10
ECM Preamp PCB board created 12-2-10
Simulation Section Updated 16-2-10
Creating the Best Diagrams in Circuit Maker by Youssef Bouterfes 19-2-10
AM Receiver New Images and Construction Tips by Austin Hellier 22-2-10
Keypad Combination Lock 22-2-10
Power Fail Alert 22-2-10
Speaker Mic Circuit Updated 28-2-10
200mW Amplifier 8-3-10
Differential Amplifier added to Tina Tutorials 8-3-10
Toggle Switch Number 3 by Ron J 8-3-10
Selecting Capacitors New article in practical Section 15-3-10
5 to 30 Minute Timer Updated 22-3-10
Periodic Timer Updated 22-3-10
Switches and Relays Updated 20-4-10
BJT Tester 21-4-10
Signal Injector / Tracer updated with pictures 12-5-10
12 Volt 30 Amp Supply paragraph on testing and faulting added 12-5-10
1 hour timer Circuit Modification
Overvoltage Circuit circuit modified thanks to Ulf Kylenfall.
IR Extender 1A some helpful tips in fault finding, thanks to Michael Corachi.
Short Wave Receiver Update thanks to Ramon Vargas 21-5-10
Ron J's Circuits Updated 23-6-2010
Modifying the Tecsun Pl380 by Graham Maynard (Media Section) 24-6-10
Mk1A Extender Updated Pictures courtesy of Michael Coracci 24-6-10
24 Second Shot Clock Mk2 by Milardo de Guzman 25-6-10
Links Updated 6-8-10
Power Zener Circuit Added 7-8-10
2 Watt Amplifier by Carlos Feldman 7-8-10
Repeating Timer 7 by Ron J 9-9-10
Hot Water Level Indicator Page Updated with new text and images 16-10-10
Basic DC Theory Updated 20-10-10
12 Volt 30 Amp Supply New images added courtesy Ryan Laurenciana from the Philippines 20-10-10
Quiz Circuit Update with Picture of Prototype 18-12-10
3 Digit Display Scoreboard by Milardo de Guzman 18-12-10
Electronic Mousetrap
Motorcycle Alarm Update by Ron J 18-12-10