The article describes a circuit which will turn off several lamps in series with a fixed delay rate, as set by the user by means of a built in pot.
The circuit operating may be known given below:
The first circuit below which happens to be a basic IC 555 and IC 4017 lamp chaser generates the simple sequencing of the lamps at the rate of 5 minutes, the time frequency being dependent upon the 100k pot setting. It has got to be set to generate a frequency which may be 50% of the preferred sequencing rate, which means here thus making it set to deliver the ON and OFf periods at the rate of 2.5 minutes.
The second circuit is a straightforward a SCR based relay driver circuit which ought to be continued 9 times across the meant outputs of the 4017 IC.
According to the request provided that the SPDT is toggled toward the ground position, the IC555 remains disabled and the first lamp(1) is held turned on forever.
Additionally within this position, all pinouts of the IC 4017 from pin2 onwards is locked at zero voltage, meaning that the attached SCR relay drivers have their relays in their N/C positions making certain that all the associated lamps stay activated.
So all the nine lamps from pin2 to pin11 of the IC 4017 has become in an started position in addition to lamp1 connected with the SPDT transistor relay driver stage.
At the most wanted period when the SPDT is toggled, the first lamp(1) is switched OFF and the 555 timer circuit is activated with its counting process.
After 5 minutes the 555 IC inputs its first legit pulse to pin14 of the 4017 making pin2 to go high which often latches the appropriate SCR relay driver switching off the first lamp in the range.
After another 5 minutes pin4 turns out high switching OFF the connected SCR relay driver lamp, and the method repeats until the last pin11 in the sequence gets triggered, switching off the last lamp in the sequence, this also also locks pin4 of the IC555 freezing the entire circuit until the procedures are reset by the user for restarting the cycle afresh.