This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for Numitron indicator valves used at the time.
This amplifier for hearing aid was found in a 1968 documentation using an integrated of the time....
We obtained this circuit from a 1993 documentation. The circuit has 9 current ranges that are...
In the figure we have the transmitter of a data transmission system with optical fiber suggested by...