Found in an Electronic Design from the 90's, this circuit measures the equivalent resistance in series of a resistor. The circuit operates at 50 kHz producing a rectangular signal.
The purpose of this circuit is to match two operational amplifiers that operate with different...
This low current circuit is suitable for powering the previous circuit and other strobe lamp...
The LEDs act as diodes, so if good they will show the same characteristic curve. Arrangment shown...