This alarm circuit was found in April 1975 Radio Electronics magazine. The circuit uses a 12 V power supply and relay but can be modified to work with other voltages.
The components of this circuit from the 70's are no longer common on the market, but it is...
This circuit produces rectangular and triangular signals using two 741 operational. The source must...
The basis of this 90s circuit is a CA3130 operational amplifier. The circuit does not need a...