The update page has grown lengthy so I have archived older work for years 2001 to 2006 in the archives below. All content is still on this site, the archive simply a chronology of when new articles and circuits were added.

Update Archive 2001-2002

Update Archive 2003-2004

Update Archive 2005-2006

A Transistor Based Burglar Alarm by Ron J 20-3-07
New Links added 21-3-07
Broken Links fixed in Miscelleaneous Circuits 21-3-07
Mark 1/1A update with a picture of a finished version by Nick (UK)Warning:
PCB for Mark 5 IR Extender kindly made by Lubo Veselsky 21-3-07
Analysis and Aplications of the Capacitive Transformer (PDF Format) by Ramon Vargas 21-3-07
150W MP3 Car Audio Amplifier by Youssef Bouterfes 21-3-07
Infra Red TV Extender by Guy Bocquillon 21-3-07
Credit Page Updated 27-3-07
Interval Timer 2 by Ron J 20-7-07
Adjustable Power Supply with Charger by Milardo de Guzman 21-07-07
Computer Output Interface 21-7-07
The Best of Thomas Scarborough Book 1 is a PDF book containing circuits made from 6 components or less. Thomas has kindly made book 1 available to everyone as a free download. Available in the Practical Section
How to Create the Best Image in Circuit Maker by Youssef Bouterfes (in the CM Simulation Section). 26-7-07
24 Watt Class A Amplifier by Marc Klynhans 27-7-07
Some corrections and broken links fixed 4-1-08
One Time Only Alarm by Ron J 7-1-08
Battery Powered One Time Alarm by Ron J 7-1-08
Telephone In Use Indicator corrupted page restored 2-4-08
Led Flasher Corrupted page restored 2-4-08
Room Monitor 10-4-08
CMOS 4060 Alarm by Ron J 11-4-08
MK5 Infra Red Repeater modification by Allan Popplewell 11-4-08
Static Detector Circuit page updated 12-4-08
Links page Updated 14-4-08
Using ECM's page updated 14-4-08
Function Generator Updated 20-4-08
Circuit Index Updated 26-04-08
New Links added 10-5-08
Audio Security Monitor 26-6-08
Hijack Alarm 3 by Ron J 26-6-08
30 Watt VHF Amplifier by David Celestin 26-6-08
Three Flashing LED Doorbells by Ron J 26-6-08
ECM Mic-Preamp Page Updated 2-7-08
6 Zone Alarm with Display 25-9-08
Media Page extended and updated 29-9-08
Temperature Monitor Updated 29-9-08
Schmitt Trigger Circuit 14-10-08
Circuit Index Updated 14-10-08
Article Index Updated 14-10-08
Antenna Tuning Unit 14-10-08
Sensitive DX TRF Receiver external link (Circuit 32) to Husnu Kokturk's web site 14-10-08
Correction to L200 PSU (pins 2 and 5 reversed) and datasheet added 27-10-08
Links Page Updated 1-11-08
BJT Bias Circuits Updated 2-11-08
Boosting Regulator Current Updated 3-11-08
1 hour timer circuit 23-12-08
49MHz Wlakie Talkie Circuit external link 23-12-08
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