Maybe a daft question but does anyone know where I can get an LED 'joule thief' circuit or IC from that is small enough to fit in a car key?

The reason is I have an old-style torch key for the Fabia that has a 1.5v 4mm incadescent bulb and a 1.5v 625U battery in it. The bulb isn't particularly bright and also drains the battery pretty quickly so figured that now the nights were drawing in I'd modify it to take an LED.

Unfortunately at 1.5v I'll need a driver to run a decent white LED - hence the query as I can't be faffed to make one.

I've found some pre-packaged IC's (Zetex ZXSC380 for example) but would need to buy 1000's when I only need one and can;t spot anything similar on the Maplin or RS Components websites.

Maybe a daft question but does anyone know where I can get an LED 'joule thief' circuit or IC from that is small enough to fit in a car key?

The reason is I have an old-style torch key for the Fabia that has a 1.5v 4mm incadescent bulb and a 1.5v 625U battery in it. The bulb isn't particularly bright and also drains the battery pretty quickly so figured that now the nights were drawing in I'd modify it to take an LED.

Unfortunately at 1.5v I'll need a driver to run a decent white LED - hence the query as I can't be faffed to make one.

I've found some pre-packaged IC's (Zetex ZXSC380 for example) but would need to buy 1000's when I only need one and can;t spot anything similar on the Maplin or RS Components websites.

I believe some cheap solar LED garden lights use them -might be worth looking for a duff one?

Phil

Maybe a daft question but does anyone know where I can get an LED 'joule thief' circuit or IC from that is small enough to fit in a car key?

The reason is I have an old-style torch key for the Fabia that has a 1.5v 4mm incadescent bulb and a 1.5v 625U battery in it. The bulb isn't particularly bright and also drains the battery pretty quickly so figured that now the nights were drawing in I'd modify it to take an LED.

Unfortunately at 1.5v I'll need a driver to run a decent white LED - hence the query as I can't be faffed to make one.

I've found some pre-packaged IC's (Zetex ZXSC380 for example) but would need to buy 1000's when I only need one and can;t spot anything similar on the Maplin or RS Components websites.

If your going to mod it why not change the power supply instead and make it 3v? maybe somehow fit 2 coin batteries (use different thinner type) in it then it can power an LED quite easily. IMO that would be the most cost effective solution, if you were wanting to mod it..

Personally I would much rather stick an mini LED light on my keys that costs pennies (which I have done) and be done with it.

Edited 16 September, 201015 yr by JLneonhug

If your going to mod it why not change the power supply instead and make it 3v? maybe somehow fit 2 coin batteries (use different thinner type) in it then it can power an LED quite easily. IMO that would be the most cost effective solution, if you were wanting to mod it.

Thank you! That is so obvious it hadn't occured to me (and backs up my wifes assertion that if there is a difficult way to do something I'll find it!)