We found this circuit in the August 1994 issue of Electronics Now magazine. The circuit is based on the now uncommon CMOS 4046. The frequency range is given by C1.
Texas Instruments SN74HCS32 Q1 2-input OR gate This Texas Instruments integrated circuit has 4...
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...
This alarm circuit was found in a 2004 documentation. The circuit searches for open NC sensors....