We found this circuit in the July 1969 Radio Electronics magazine. The circuit uses a coupler made with a lamp and an LDR. The power of the lamp determines the types of diodes.
This circuit is from an English magazine from 1980, but it can be easily assembled with more...
Found in Philips' 1968 documentation, this circuit serves as a 6.3 V reference for high stability. |...
In critical applications of the RS-232 interface, the danger of induced voltages in the cables must...