This is a 1.2 – 12 V, max 1A power supply with a low voltage indicator LED. The indicator part includes three diodes and one LED. For example you are charging a battery, you can observe the charge ...

Even today much logic is still powered from 5 volts and it then seems obvious to power the circuit using a standard regulator from a rectangular 9-V battery. A dis-advantage of this approach is that ...