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light, that requires me to push a button to have it turn on but that has a slight delay before turning off. Answered

I need to build a light with a large button that you can press. kind of like a buzzer, but that makes no sound, instead it turns on a light that remains on for a few seconds before turning off. It mustn't be a toggle switch, but instead a push switch.

I have a basic understanding of  electronics but if someone could point me in the right direction so I could at least try to make it that would be awesome.

I'm not picky this time around I'm willing to have anything emit the light, whether EL Wire, a light bulb or LED.

Whatever is simplest is probably best this time around.

Hopeful and excited,




7 years ago

you can use a capacitor and a relay. when the switch is closed it charges the capacitor when the switch is released the relay will remain closed for a time determined by the size of the capacitor.

It sounds like you want the light to turn on immediately, and then turn off after a delay. If that is the case, then this sounds like a job for the basic 555 timer configured as a one-shot (monostable). It will produce an output that goes high immediately after the button is pressed, and the output will stay high for a length of time determimed by a resistor and capacitor.

The output can be used to turn on whatever kind of light you need. If its just a single LED, it can be directly connected to the 555 output along with a resitor to limit the current. If it is a 120 VAC 1000 Watt floodlight, the 555 output can turn on an appropriately sized solid state relay to control the load.

The 555 timer circuit should be easily locatable on this site or elsewhere on the web.

You don't need any electronic components to do this. You can buy a large push button type switch at an electrical wholesaler that does exactly what you need. They are the size of a common light switch plate with a large diameter push button, and are made to be used in stairwells so you can turn the lights on at the top or bottom of the stairs and they time out without you having to turn the switch off again.

Do you want the light to turn itself off, after it has been on for a few seconds, i.e. you push the button, the light turns on, a few seconds later the light turns off, and it stays off until you push the button again?

Or do you want to, push the button, which makes the light turn on, without delay, then the light stays on, forever if necessary, waiting for you to push the button again, and when you do push the button again the light stays on for a few seconds then turns off, and stays off, forever if necessary, waiting for you push the button to turn the light on again?

Should be a fairly simple circuit, I'll give you some things to ponder and google further.

You need a pair of monostables. Pushing the button triggers the first. This causes a delay. The falling edge of the first monostable will be the trigger for the second monostable, the output of which will trigger your light source.

This page seems fairly complete and should help you out: http://www.kpsec.freeuk.com/555timer.htm

There's a section on making them edge triggered too. You can ignore anyone that tells you that you need a microcontroller for this, you really don't.