In the figure we have the way to obtain the Exclusive-OR function with 1 transistor. The circuit is from a 1964 Electronic Design. The transistor can be any general purpose PNP.
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...