There are 160 circuit schematics available. Last circuit added on Tuesday, 19 May 2015.

CircuitCategoryDate AddedOK?
13.8V 30-40A Power Supply (PDF)Power 
DC Voltage and Current SourcePowerMar 25, 2009
Power supply provides +5VDC regulated, +10VDC unregulated and 7.5VACPowerJan 26, 2001
Controller for hybrid (photovoltaic- wind turbine and diesel engine) power plantPowerMar 25, 2009
3rd harmonic distortion meter for measuring the quality of AC supplyPowerMar 25, 2009
Car Ignition Coil Driver from 110V ACPowerSep 23, 2009
Amplified zener regulatorPower 
Car Ignition Coil Driver from 12V DC - Can be used as an electric fencePowerSep 23, 2009
Battery Charger, Current and Voltage Regulated for Sealed Lead Acid batteriesPower 
Voltage and current regulated power supplyPowerSep 23, 2009
Simple switching power supply (mains operated)PowerSep 23, 2009
12 Volt Switching Power Supply circuit diagram and PCB layoutPowerSep 23, 2009
Simple voltage booster based on Linear Technologies LT1372, includes PCB designPowerSep 23, 2009
Alkaline battery chargerPowerDec 02, 2002
Highly accurate constant current source using LM4140, OP777 and MOSFETPowerMar 17, 2014
Dry cell battery chargerPowerDec 07, 2014
Power Supply Resumption Alarm using 555 timerPowerOct 25, 2014
Solid-state voltage indicator with high voltage cutoutPowerDec 07, 2014
Stabilized Power Supply With Short-Circuit IndicationPowerOct 25, 2014
Capacitor voltage stepper using 555 timerPowerDec 07, 2014
Low Voltage Alarm for batteries and other volatile DC power sourcesPowerJun 26, 2009
Voltage Monitor using UA741 operational amplifierPowerOct 19, 2009
Expanded Scale Battery Volt MeterPowerSep 17, 2009
Battery Low Voltage BeeperPowerSep 17, 2009
Low Cost Universal Battery ChargerPowerJan 08, 2014
26V-to-5000V DC-DC ConverterPowerJan 08, 2014
Fast Charger for Better Lead-Acid Battery LifePowerOct 03, 2013
5 A Constant Voltage-Constant Current RegulatorPowerOct 03, 2013
1A Variable Regulated Power SupplyPower 
Regulated Power Supply CircuitsPowerSep 10, 2006
Basic Solid State RelaysPowerSep 10, 2006
LM311 Thermostat circuit diagramsPower 
Transformer Secondary Voltage ReductionPower 
Back And Forth - Bidirectional Bipolar Stepper Motor DriverPower 
High Side Current Monitors (LM358, Zetex - ZXCT-1009)PowerSep 10, 2006
Low Battery Voltage Cutout CircuitsPowerSep 10, 2006
Preselect Twin Coil Switch Machine CircuitPower 
N.O. Magnetic Reed Switch ON /OFF Circuit (SCR equivalent)Power 
Team digital - SCR16 - Twin Coil Switch Machine AdapterPower 
Efficient unipolar stepper motor driver (only uses power when it makes a step)Power 
Alternative power source for Magellan GPS receiversPowerMay 01, 2004
Battery voltage monitor using an LM358 op-ampPowerApr 12, 2014
0-14 volt, 0-2 amp current limited variable power supply regulatorPower 
A Variable power supply with adjustable current limiting. 0-14V output up to 5A current.PowerApr 12, 2014
Dynamo Current and Voltage RegulatorPowerSep 21, 2006
General purpose portable DC power supply using rechargeable C cellsPowerFeb 05, 2010
Bench power supply that allows a number of varying output voltages to be preset. Includes PCB layoutPowerFeb 26, 2010
Power supply metering circuits for measuring both voltage and currentPowerFeb 09, 2010
Emergency power systemPowerMay 16, 2010
Digital bench power supply based on a PIC16F870PowerMay 24, 2010
Lithium Ion Battery Charger based on a PIC micro including circuit diagram and source codePowerMay 24, 2010
6V to 12V ConverterPower 
Automatic 12V Lead Acid Battery ChargerPowerSep 01, 2009
Solid State Tesla Coil/High Voltage GeneratorPowerSep 01, 2009
12V to 120V Inverter circuit diagramPowerSep 01, 2009
Basic Power SupplyPowerSep 01, 2009
High Current Power SupplyPowerSep 01, 2009
Dual Polarity Power SupplyPowerSep 01, 2009
High Voltage High Current Power SupplyPowerSep 01, 2009
Transformerless Power SupplyPowerSep 01, 2009
Fixed Voltage Power SupplyPowerSep 01, 2009
Voltage Inverter using 555 TimerPowerSep 01, 2009
Voltage Inverter using LM380 audio amplifier ICPowerSep 01, 2009
Dual power supplyPowerJan 31, 2003
Negative voltage generatorPowerAug 12, 2001
Power reminder beeper (PDF)PowerJan 26, 2001
Unplugged power cord alarmPowerJan 26, 2001
Machine power loss beepter (PDF)PowerJan 26, 2001
Simple NiCad battery charger using LM317PowerAug 17, 2009
Op-Amp Current Source with Floating Load including SPICE simulationPowerMar 26, 2011
HV supply: 12VDC in, 12KV outPowerJan 26, 2001
Generating -5VDC from +5VDCPowerJan 26, 2001
Filtering PC bus POWERPowerJan 26, 2001
Dual Polarity Unregulated PSU For High-End Audio AmpsPowerNov 13, 2010
High Voltage Converter: 90V From 1.5VPowerNov 13, 2010
Charge Monitor for 12V lead acid batteryPower 
NiCd Cell ChargerPower 
Basic UPS Power SupplyPowerFeb 21, 2005
Fuse monitor / alarmPowerFeb 21, 2005
Voltage monitor with LED indicatorPowerFeb 21, 2005
High current regulated power supplyPowerOct 31, 2002
Adjustable power supply using LM317PowerJan 26, 2001
Simple +5V power supply circuitPowerJan 26, 2001
One 9V battery gives +18, +25, +33VPowerJul 24, 2002
+9V *and* -9V from one batteryPowerJul 24, 2002
Basic 78xx series regulator mains power supply circuit diagramPowerOct 25, 2009
USB charger circuit diagramPowerAug 18, 2009
Advanced High Voltage PSU circuitPower 
12 Vdc - 120 Vac Inverter SchematicPowerJan 01, 2003
Single to 3-phase power conversionPower 
DC Voltage and Current SourcePowerMay 19, 2015
Student DC power supplyPowerJun 19, 2011
Circuit that provides a short circuit protected power supply from PC 12V supply voltage.PowerMay 19, 2015
+/-5A Voltage Controlled Current SourcePowerMay 19, 2015
Breadboard supply - very low dropout adjustable power supplyPowerOct 12, 2009
Small battery-powered USB charger including circuit diagram and PCB layoutPowerOct 12, 2009
3.3V / 5V Regulated Power Supply CircuitPowerJul 03, 2011
Lead-Acid Battery MonitorPower 
Simple switching power supplyPowerJul 10, 2002
AC Power MeterPower 
Assorted power source and control circuitsPowerMar 18, 2003
Build A Simple Rechargeable CMOS BatteryPower 
Build A High Performance Voltage Regulator From Discrete ComponentsPower 
12 Volt Gel Cell Charger circuit diagramPower 
Build A 10 Amp 13.8 Volt Power SupplyPower 
Adjustable Voltage Regulator using a 7805 or other fixed linear voltage regulator instead on LM317Power 
Using Pass Transistors Beef Up Voltage Regulator current outputPower 
12 volt battery monitor circuit diagramPowerJan 26, 2001
12 volt power supply circuit diagramPowerJan 26, 2001
5 volt power supply circuit diagramPowerJan 26, 2001
Battery voltage monitor circuit diagramPowerJan 26, 2001
LM3914 battery monitor circuit diagramPowerJan 26, 2001
Multiple voltage power supplyPowerJan 26, 2001
Voltage doubler using a 555 timerPowerJan 26, 2001
Voltage inverter using a 555 timerPowerJan 26, 2001
Simple switching regulator (experimental)PowerNov 16, 2002
Build a breadboard power module for integrated circuitsPowerSep 30, 2009
DC to AC inverter using a 555 timerPower 
Dual (postive and negative) 12V power supplyPower 
Current booster for 78nn series voltage regulatorsPower 
12V Lead-Acid Battery Monitor using LM3914PowerJan 08, 2002
Charger for gel lead acid batteriesPowerJan 26, 2001
Compressor-mate power protection for refrigerators, freezers and air conditionersPowerOct 06, 2006
High voltage DC generatorPower 
High-Voltage Pulse GeneratorPower 
Automatic 9V NiCad battery chargerPower 
Active Power ZenerPower 
Solid state relay circuitPower 
NiCad Discharger for Tx & Rx PacksPower 
Lead acid battery charger with floatPower 
Simple constant current sourcePower 
Power Supply for Vacuum Tube ExperimentsPowerMay 19, 2015
Nine Volt Battery EliminatorPowerSep 07, 2009
PWM DC Motor Speed ControlPowerSep 21, 2006
Battery Low Voltage BeeperPowerSep 21, 2006
PWM Motor Speed Controller / DC Light DimmerPowerJul 12, 2001
PWM Motor/Light ControllerPowerJul 12, 2001
Low Power LED VoltmeterPowerJul 12, 2001
WGR1 - 12 Volt Wind Generator RegulatorPowerMay 19, 2015
Expanded Scale Battery Volt MeterPowerSep 07, 2009
Temperature Controlled Nicad ChargerPowerSep 21, 2006
12V, 4-AA Cell Differential Temperature ChargerPowerAug 17, 2009
PWM Motor/Light ControllerPowerJan 26, 2001
PWM Motor/Light Controller variantsPowerJan 26, 2001
Low Power LED VoltmeterPowerJan 26, 2001
Temperature Controlled NICD ChargerPowerJan 26, 2001
Battery Charger IdeasPowerAug 14, 2002
Windmill DIY Analog MPPT (maximum power point tracker) CircuitPowerMar 09, 2012
Battery CharacterizerPowerJul 24, 2002
Lead/acid battery chargerPower 
200 Watt Modified PC Power Supply 13.5 Volt 14 AmpPowerJul 24, 2002
12V 30A power supply circuit diagramPowerJan 26, 2001
Dual regulated power supplyPowerJan 26, 2001
Fuse blown indicatorPowerJan 26, 2001
Gyrator circuitPowerJan 26, 2001
Variable power supplyPowerJan 26, 2001
LM317 Regulator CircuitPowerNov 27, 2002
Nicad battery chargerPowerJan 26, 2001
Regulated 12V supplyPowerJan 26, 2001
Unregulated power supplyPowerJan 26, 2001