In this oscillator circuit using 3 TTL inverters we have all the conditions for the frequency calculation. Power must be supplied with 5 V. The circuit is from an American TTL documentation.
A ring and pendulum of stripped wires form the sensor for this alarm. Once triggered, to reset, you...
This radiation detector was found in an American publication from the 60's. The circuit uses a...
In the figure we have a simple timer with the 555 feeding a relay directly. The circuit is from...