L E D advise?

[POPEYE]

Cheers Matt/guys,

[Pine12]

Thought i might be "overdoing it" on those adaptors, just counted the fish tank leds and theres 34 of em rangeing from 10mm amber through 5mm red and blue and 3mm green and some colour changeing ones, prob why the adaptor's getting frickin hot, would than be right?

Yes

As a general LED's that are supplied without resistors only require 0.6V across them to make them conduct. As a rule a standard red LED's maximum current is 30mA and at 12v you need a 470 Ohm resistor to ensure that maximum is not exceeded (it will actually limit the current to 25mA). So as you increase supply voltage the resistance will have to increase to keep the current constant and vice versa as you decrease the voltage, hence ohms law.

Just found this link tells you all about it http://www.kpsec.freeuk.com/components/led.htm

Not trying to appear smart, just thought you might be interested. Sorry if it appears i teaching you to suck eggs!!!

Cheers,
Graham

[MattF]

Ian, he's getting all technical on you.

[POPEYE]

He is!
i've fitted loads in the truck but they were fairly simple circuits, i always tend to fit one 470ohm resistor to one led to keep it simple in my mind (or my simple mind) to avoid me setting fire to the fish i think i'll do what bdt said, get a smallish battery and a solar trickle charger and run everything from that, thanks for the link tho i'll print that and keep it for future reff,
thanks all!

[00Brood]

It might me a off the wall suggestion… but if you have a old pc power supply floating about you can use that and its quite high powered… and you have the essentials voltages:

12V roughly about 10A
5V roughly 15-20A
3.3V roughly 30-50A



Its just rough figures but useful… I power a lot of things from an old pc power supply… if you need any further help on getting the circuits ready etc… drop me a mail and I’ll see what I can do ;-)

Cheers
Brood

[POPEYE]

It might me a off the wall suggestion… but if you have a old pc power supply floating about you can use that and its quite high powered… and you have the essentials voltages:

12V roughly about 10A
5V roughly 15-20A
3.3V roughly 30-50A



Its just rough figures but useful… I power a lot of things from an old pc power supply… if you need any further help on getting the circuits ready etc… drop me a mail and I’ll see what I can do ;-)

Cheers
Brood

Thanks mate, apprecieate that and will bear it in mind, we dumped a pc power supply not so long ago! bugga!! however my sons in the IT business so hopefully he can "come across" one for me, if i can find a decent priced battery and triccle charger tho that will do,

[Apache]

What about lighting transformers? I have one which was powering 6 x 50w halogen spots, but is now powering LED spots which have 30 or so LEDs in each.