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.
This circuit came out from the Linear Circuits Applications of Texas Instruments, based on the...
This 4-digit digital clock for hours and minutes with CMOS integrated circuits was found in a 1995...
This circuit takes advantage of the LC constant of a capacitor and the coil of a relay to...