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 sensor circuit for currents of the order of nanoamperes was found in an American...
This circuit was obtained from a 1964 magazine and has some interesting features such as the input...
Suggested by a 90’s Radio Electronics, this circuit automatically activates the recording switch of an...