Using the 555 and 7400 this circuit was found in the September 1977 Radio Electronics magazine. The power supply must be made with a voltage of 5 V.
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
The figure shows how to implement the AND function with a Norton LM3900 operational amplifier. The number of...
A single high-power transistor MJ15003 is used in the circuit in the figure to generate strong...