Found in a 90’s 73 magazine for radio amateurs, this circuit provides a few milliamps of output with -15 V from a 3 V input, when the consumption will be 10 mA.
This circuit with TTL output was found in a 1968 EEE. The transistor can be of general use. The...
This 100-second timer was found in a 2000 Poptronics. The magazine no longer exists, but the...
This control for a small servomotor with a current of a few hundred milliamps was found in an...