This optically coupled circuit was found in the February 1968 Radio Electronics magazine. The circuit uses an LDR in modulation. Transistors are types of the time.
With this circuit a logic output signal from a microcontroller or other digital TTL configuration can...
Found in Maxim's documentation from the 90's, this circuit uses a component from the time and has its...
This circuit drives 4 sequences of 5 LEDs that can be of any color. The frequency depends on the...