i know they use a high voltage, i was thinking maybe some of them come with the booster built in now, or EL drivers are available
wle
Yes yes glo toob
Those are definitely in my wishlists till now but the price just made me buy proper lights instead hahaa
Someone needs to invent coin cell batteries assembled with built-in LEDs or a COB strip. Pull out a little insulating strip, and it lights up.
I wonder if solid state electronics exist small enough to do that along with an off-during-daylight sensor/switch.
Or, you just make a slightly larger coin cell sized light that has a slot for a coin cell battery you just slip in. It can have an incorporated pull tab where you pull it to activate then push in to turn off. Magnet on the back.
Y’mean a throwie?
There is always this, the cost is pretty high, but if you get a high enough content of radium it is pretty bright. of course there might be some health considerations
Here’s the DIY version. About a dollar each or less in quantity.
Here’s an instructable how-to.
A photoresistor or phototransistor allows more current when it’s in the light, so you can’t just put them in series with the LED to shut it off. You’d need a slightly more complex circuit as in” this instructable”:https://www.instructables.com/id/LED-nightlight-that-turns-on-in-darkness/. With SMD devices, you could fit it all in the outline of the coin cell.
@wle - I was mentioned the high voltage to point out that it probably puts it out of the energy budget. Maybe not, though.
Adafruit: Each meter of high brightness EL draws about 10-15mA at the high voltage, which means about 1.5 Watt/meter (at 100VAC).
The boost / invertor circuit would probably not be all that efficient, but could be tied to the main battery. If you could drive a reasonable (1cm?) length at a 1-10mA budget, you’d be looking at only 30 or so hours per battery.
You guys have my wheels turning on this, despite me having no actual use for it :person_facepalming:
I had considered trying to integrate a 10180 with openings for charging, a small PCB, some SMD LEDs, and a 3D-printed housing. But now I’m wondering if it would be better to just use a CR1632. With a small draw (0.05 mA, perhaps) it would last approx 4 months. You could go even lower for longer runtimes. It could probably be as small as ~22mm diameter x 6mm tall.
The coin cells (such as CR1632) have an extremely flat voltage curve at ~2.9V until they’re dead which means fairly consistent brightness and very little excess voltage to burn off. And with a coin cell, there’s no need for a protection circuit - just run it until it’s dead. Hmm…
I have lighted tail caps for sale, they can last well over a year with low drain
For sure, I agree Lexel. Where you can, a good lighted tailcap is indispensable.
While we have your attention, have you ever seen the HM1160 ? Sure, it’s not as configurable as individual voltage references or voltage reset monitors, but having a SOT23-6 footprint 4-level battery monitor IC sure is compact and convenient (and cheap, too!).
some coin cells are rechargeable iirc
those for rtc clocks. Even some keychain solar light uses them.
looks similar to cr2032 but rechargeables
Those are the LIR series coin cells, such as LIR2450. Capacity (per volume) is much lower than their non-rechargeable brethren. And they’re many times more expensive. And then a protection circuit would be needed (a simple voltage reset monitor would suffice, but it further complicates things. These things are acceptable depending on what you want the end result to be. That is, would the extra size (or decreased runtime) and expense worth it to make it rechargeable?
Supercap…