This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time. The circuit is from the 90's, not being given the power supply.
This circuit can be used with high power LEDs supplying currents from microcontrollers and digital...
The integrated circuit used in this regulator is not common today. The circuit is from a technical...
We find this circuit in an 80's EDN. The circuit can be used with equivalent operational,...