This circuit was found in an 80's EDN. The circuit uses a current common CMOS, the 4093 powering an LED. Trigger adjustment is done in a trimpot.
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...