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I need to add a time to flashlight or lantern so that it will switch itself off after maybe 20 seconds, what is the simplest way to do this please?
I'd imagined it activating with a momentary switch, then maybe a dial /potentiometer to adjust the time, which would definatiely be less than a minute. I don't have any way to make up a pcb so please bear that in mind, thankyou
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1 year ago
Capacitor discharge is an old-school timer. Not precise, but simple.
1 year ago
The MOSFET Gate gets charged and lights the LED until R2C_seconds discharge falls below 66%...
Pick the FET that works the current needed, (2N7000 - 100ma) or (BS170 - 500ma) and adjust the R1 value appropriately.
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