The circuit shown is from 1994 National Semiconductor documentation but can be implemented with more modern operational amplifiers. The power supply must be symmetrical.
This low power metronome produces pulses in a small loudspeaker. Pule rate is adjusted by P1 and...
This simple two-transistor capacitance meter uses a 50 uA microammeter as an indicator instrument. The...
Found in a publication from the 60's, this power supply has no regulation, but only current...