This alarm with NO and NC sensors was found in the January 1975 Radio Electronics magazine. The circuit emits a powerful sound that depends on the output transistor.
One of the LM3900's four Norton operational amplifiers is used in this oscillator, which has an...
We found this circuit in Motorola's 1990 Linear Databook. The component used is unusual. The...
The components of this circuit are exchanged for modern equivalent such as 470 K for the pot and...