Found in documentation from the 1990s, this circuit converts 12 V to 9 V from a car's power output. The 100mA current eliminates the need for a heatsink on the transistor.
This circuit multiplies the input voltage by 3 and can work with up to 12 V input. The current is a few...
This circuit was obtained in a Hands-On Electronics from the 90's. The circuit turns on one LED at...
This telegraph monitor was found in an American documentation for radio amateurs from the 1970s. The...