This Schmitt optical trigger with LDR was found in old documentation. The relay must be sensitive, or an additional step must be used to trigger it.
I found tis circuit in na old documentation from 1958. The circuit uses germanium transistor...
This circuit squares the waveform of a signal applied to its input. The circuit is from an old...
ON Semiconductor MC74VHX1Gx Logic ICs The Mouser Electronics series 74 Logic ICs are available for...