| The Civil
Twilight Switcher (CTS) is a micro-controller based system
for automatically switching the Street Lights on and off
according to the timings stored in the system for each
day of the year. The present system is programmed for
the timings as enclosed. The system contains a Real Time
Clock (RTC) chip with a ten years battery backup. This
keeps track of the date and time.
Each day, at the stored ‘ON’ time, the triac
drive is activated and switches on the Phase Output
of the system. The input phase to the triac circuit
is given through a fuse of 4 Amps rating. So the maximum
load allowed through on CTS is limited to 4 Amps. Similarly,
at the ‘OFF’ time, the triac is switched off
and this switches off the Phase Output supply. For example,
consider the case of a typical day - May 7. On this
day at 19.12 Hrs., the streetlights will be switched
on. The next day, at 5.58 Hrs, the lights will be switched
off. The Phase Output and Neutral Output are to be connected
to the coil of the contactor controlling the Street
Lights.
An LED indicator is provided on the front plate of
the cabinet that switches on and off every second. This
is an indication that the micro-controller is working
properly.
The CTS gives direct savings from 8% to 22% depending
on the type of device used.
|
