This shield circuit is from a 1968s Motorola documentation. The relay is according to the supply voltage. R1 can be reduced to lower trigger voltages.
This circuit mimics the sound of a siren when we turn the axis of the small DC motor. The...
This sophisticated RPM counter circuit with discrete integrated circuits was obtained in a 1993...
This circuit uses complementary transistors and was found in Mullard's transistor application...