Power circuit diagrams

Mains Remote-Alert

Beeper and/or LED remotely-operated via mains supply line Simple circuitry, easy to build units

120 and 240Vac LED Voltage Indicator

Useful for power lines control. Simple, transformerless circuitry

Add-On Current Limiter for Power Supplies

This circuit allows you to set a limit on the maximum output current available from your PSU. It's very useful when you power-up a project for the first time - or carry out a soak-test.

Smart Trailing Socket

Mains sockets switched automatically by a Control Socket Up to 1000W switched power

Radio Friendly Power Supply

Power supplies should not create any unwanted interference across the radio spectrum. Switch mode power supplies are one of the strongest sources of interference, and harmonics can be heard throughout long, medium and short wave bands. This power supply, is extremely noise free, and therefore radio friendly. In addition, it has a very high rejection of line frequency and is suitable for powering receivers and small power transmitters.

Alarm Power Supply

A 12 Volt power suppiled designed for Ron's Modular Burglar Alarm. However, being a popular supply voltage this circuit will have many other uses as well.

Neon Desklamp

This circuit will power a 6 inch 4 Watt fluorescent tube off a 12 volt supply, consuming 300 mA. It may also be powered by a suitably rated universal AC/DC adapter. Advantages of the design are: good light, low power consumption, and readily available stock parts.

Soft Start PSU

Two soft start power supplies. The output voltage slowly increases to the desired output.

9 Volt 2 Amp PSU

A simple 9 Volt 2 amp supply using a single IC regulator.

Adjustable Constant Current Load

An adjustable power load is a piece of test equipment that often comes handy in the development of certain electronics projects. For example, when you are building a power supply, it will come a time when you need to "simulate" a load to see how well your design performs as the load varies. Adding power resistors to the output can sometimes do in a pinch, but often you will not have the right resistor value handy with the right power rating for the test. This is where an adjustable electronic load comes handy. In this article, I'll show how you can build one using common components available to the electronics hobbyist.