15v LED Circuit

[varistor]

Hi guys

A very stupid question from a mechanical engineer

If you have a 15v LED (The type that can run directly on 15v) in series with a 510 ohm resistor connected across a 15v dc supply would the led light? Is it an acceptable thing to do by adding additional resistors in line like this. I guess this has been done to dim the led

Basic question I know,but as I say i am mechanical

 

[OperaHouse]

Chances are you can increase the resistance up to 5,000 ohms and still have a visible LED under some lighting conditions.

 

[IRstuff]

It really depends on the operating current. If its no more than 30mA, then there's some hope that it'll just be dim. If it's more than 30mA, then you'd need a smaller resistor.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[varistor]

Thanks for the responses

I believe the LED in question is about 15mA

 

[Skogsgurra]

The 'varistor' handle is pretty untypical for a mechanical guy. Is there a story behind it?

BTW, if it is an ordinary LED that draws around 15 mA, you probably have a 1200 ohms resistor, or similar, in series with it already. Adding 500 ohms will surely make it dimmer, but you will not notice next time you look at it. Unless you have more LEDs and only one has the extra resistor.

Gunnar Englund

http://www.gke.org

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Half full - Half empty? I don't mind. It's what in it that counts.

 

[VEBill]

It's usually pretty easy to tack-solder a jumper wire in parallel with a resistor of 1/4 or 1/2 watt size, even with access only to the top side of the circuit card. Turn off power first, obviously.