Found in Radio Electronics from the 90s, this circuit uses components from that time. However, it can still be elaborated with some ease.
This circuit was found in 1978 documentation, using the National Semiconductor's LM380. The...
April 2017 - The new Alps UGMZ2AA Bluetooth communication modules can be found on Mouser...
This configuration triggers an external circuit or simply an LED for time given by R1 and C1 (T =...