# 8V DC Power Supply With Over-Voltage Protection

Schematic Diagrams      Comments Off on 8V DC Power Supply With Over-Voltage Protection

This 8V DC power supply was designed for use with an expensive piece of electronic equipment. It features full over-voltage protection as a precaution against regulator failure, either in the supply itself or inside the equipment it is powering. The circuit uses a conventional full-wave rectifier, followed by a 3-terminal… Read more »

# 7.2V Battery Replacement Power Supply For Camcorders

Schematic Diagrams      Comments Off on 7.2V Battery Replacement Power Supply For Camcorders

This circuit lets an external 12V SLA battery power a camcorder which normally has an inbuilt 7.2V battery. Such batteries can now be very difficult or expensive to obtain for earlier model camcorders. In essence, the circuit is a standard LM317 adjustable regulator with resistors R1 & R2 set to… Read more »

# Reset from Multiple Power Supplies

Schematic Diagrams      Comments Off on Reset from Multiple Power Supplies

Processor based systems usually require a voltage supervisor chip to produce a clean reset pulse to the processor whenever a ‘brown-out’ condition of the power supply is detected. More complex designs employing multiple power supplies can be unreliable if some of the supplies are not supervised. The circuit described here… Read more »

# Battery Replacement Power Supply

Schematic Diagrams      Comments Off on Battery Replacement Power Supply

Your child’s battery toy has failed and you have to fix it. Once you have managed to get it apart, the battery compartment is not likely to be connected to the works or the batteries might have gone flat anyway. The solution is this switchable supply which is designed to… Read more »

# Soft Start For Switching Power Supply

Schematic Diagrams      Comments Off on Soft Start For Switching Power Supply

Switching power supply whose output voltage is appreciably lower than its input voltage has an interesting property: the current drawn by it is smaller than its output current. However, the input power (UI) is, of course, greater than the output power. There is another aspect that needs to be watched:… Read more »

This project details the design of a very low dropout adjustable power supply. A good power supply is essential to electronic projects. While there are many existing designs for adjustable power supplies, this one makes improvements that make it more useful for hobby designs MIC2941 regulator has guaranteed 1.25A output… Read more »

# Dual Power Supply For Amplifiers

Schematic Diagrams      Comments Off on Dual Power Supply For Amplifiers

A power supply suitable for use with the 60W amplifier presented in the predeeding project is perfectly simple, and no great skill is required to build (or design) one. There are a few things one should be careful with, such as the routing of high current leads, but these are… Read more »

# 13V/2A PSU For Handheld Rigs

Schematic Diagrams      Comments Off on 13V/2A PSU For Handheld Rigs

This compact 13-V/2-A power supply for ham radio rigs and other VHF/UHF portable PMRs is based on the STR2012/13 voltage regulator IC from Sanken Electric Co. Many power supplies for handheld amateur radio rigs are based on the LM317, LM350 or even the good old LM723. Unfortunately, these regulators are… Read more »