This dual flasher for high brightness LEDs was found in an American documentation from the 90's. The circuit can be powered by lower voltages with the reduction of R1 and R4.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
I found this circuit in an Electronics Handbook from 1989. The circuit can be assembled with a...
This circuit makes use of a 2N301 germanium power transistor. We found it in a documentation from...