Found in a Hands On Electronics from the 80's this circuit allows the reading of low resistances in a common multimeter. The circuit consists of a constant current source.
The integrated circuit in this application for 6 V motors is not common today. The circuit is from...
When this circuit picks up a louder sound it produces a pulse that briefly charges the 10 uF...
The circuit is from the Linear applications Handbook of the National Semiconductor of 1994. The...