The master clock uses Micro-controller based circuitry. Its Clock functions are generated from a quartz controlled RTC chip. The uniqueness of this chip is that it is backup on power failure by a LITHIUM battery and the low power consumption of the circuit gives a long battery life. The time is displayed using four digits of RED LED displays, two digits to the left . for HRS. and the two digits to the right for MINS. Two rugged Push-to-ON switches are used to set the clock