Blinking red LED with a coin [button] cell
Posted: Sat Oct 14, 2017 6:31 am
Using an "off the shelf" red blinking 5mm LED [3v. 20 ma] and a small current limiting resistor controlled by a tilt switch (very simple so far) but since small size is very important I would like to power this with a coin cell [button cell] or two that are no larger than a quarter [25 cents] and no thicker than 1/4". This will be encased in epoxy so changing the battery is not an option.
The desired end result would operate [on blinking] for 10 to 15 seconds around 4 or 5 times in a 24 hour period and last as long as possible. A year would be perfect.
Coin cells like a CR2477 have a 1000 mAh rating which to a novice like me means that it would operate a 20 ma LED for a long time. I want to make a "PUT THE TOILET SEAT BACK DOWN" reminder to "attempt" to teach my son and keep both of us out of trouble. Seat up - light blinks and seat down it's off.
Am I on the right or wrong track with the battery choice? Does anyone have a better battery choice?
I am open to any and all suggestions and thanks in advance for reading this.
The desired end result would operate [on blinking] for 10 to 15 seconds around 4 or 5 times in a 24 hour period and last as long as possible. A year would be perfect.
Coin cells like a CR2477 have a 1000 mAh rating which to a novice like me means that it would operate a 20 ma LED for a long time. I want to make a "PUT THE TOILET SEAT BACK DOWN" reminder to "attempt" to teach my son and keep both of us out of trouble. Seat up - light blinks and seat down it's off.
Am I on the right or wrong track with the battery choice? Does anyone have a better battery choice?
I am open to any and all suggestions and thanks in advance for reading this.