This filter is current driven and has the formulas given by the two diagram options. The circuit is from an American documentation from the 90s applying to any operational amplifier.
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...