Timer for Geyser Circuit Diagram

The circuit comprises a timer IC 555 wired as an astable multivibrator with adjustable time period of 15 seconds. The astable output after inversion by an inverter drives decade counters IC3 and IC4 (each IC 7490) connected in cascade. Timer for Geyser Circuit Diagram The decade counters output is connected to decoders IC5 and IC6 (each IC 7442), respectively. The decoder outputs (Q8 outputs of IC5 and IC6) are fed to inverters and the inverter outputs, in turn, are fed to an AND gate. The AND output is connected to the reset pin of the astable multivibrator built around another timer IC 555 to sound the alarm. Now you can turn off the geyser. A green LED (LED1) has been used as the power supply indicator. Switch on the timer and the geyser at the same time. When the alarm sounds, it means that the water in the geyser has heated up and can be used.You can assemble the timer circuit on a general-purpose PCB and install it near your bathroom so that both the timer circuit and the ge...