This circuit was found in a Ferranti documentation from 1969. The transistors are common types of the company at the time. Smaller equivalents may be used. The output power is of the order of 150 mW.
This simple circuit for a common 110 V power grid was found in a 1980s American documentation. The circuit uses...
What this circuit does is to stretch a pulse, increasing its duration. The integrated circuit is...
This simple circuit was found in a 2001 documentation. With each touch of CH1, a 4017 output...