This circuit maintains on a flashing LED at a frequency determined by the capacitor. The unijunction transistor can be 2N2646.
This circuit is used in magnetic tape recorders, having been found in documentation in the 1960s....
The sensor for this light relay found in a 1967 Japanese magazine is a common photocell. The...
This circuit was found in a 90s Electronic Design. The circuit directly controls a triac that is...