battery

The LED stick bright when volt of battery model to load new get agree lower 8.3V ( for battery 9V). Which be minimum value that can agree, be a signal know that battery, want to load new already. The circuit can modify to go to apply to transistor radio for is warn change [...]

This simple circuit is a DC-DC converter that converting up 12V source to a 24V. It can be used to run radios, small lights, relays, horns and other 24V accessories from a 12V vehicle with a maximum draw of about 800mA.
his DC-DC Converter can be used to charge one 12V battery from another, or step [...]

A common need in many systems is to obtain positive and negative supplies from a single battery. Where current requirements are small, the circuit shown is a simple solution. It provides symmetrical +&- output voltages, both equal to one half the input voltage. The output voltages are referenced to pin 3, output common. If the [...]