Security Lights: On/Off/On to stay on

[Fred.Amoson]

Hello,

On motion sensitive lights in order to turn off the motion sensitive part and make the light stay on all of the time you flip the power switch on, then off, then on again quickly. This will cause the lights to stay on until you turn the switch off and on again.

I would like to make a circuit that works on a similar idea. What would be the best way to do that? Does it require a microcontroller or in there an easier way?

 

[h.d]

you can use MCU
or IR sensor +led+relay

 

[mneary]

Put a capacitor in a long (8 second) RC. I suggest 1 megohm and 8-10 microfarads. Make a latch from a pair of NAND gates, and hook the capacitor (C1) to one input. Make a similar RC network of 1 second, hook it (C2) to the other input.

Operation: If C1 is discharged and you turn the switch on, C1 will take longer to reach a "1" than C2. C1 will therefore set the latch. If you allow C1 to charge, it will stay at a "1" value for a while after the switch is turned off. If the switch is turned back "on" before C1 has discharged, it will be a "1" while C2 is a "0", and the latch will be reset.

 

[picbits]

I worked for a company many years ago which made commercial security products and they had a similar design on a switch but used comparators with a couple of caps to latch when the switch was flicked on and off.

 

[Fred.Amoson]

Thanks for the info, that should work great!