High Intensity LEDs

[c7kjt]

I'm sure this was covered many moons ago, but I'm looking for a source of 12V high intensity LEDs that I can use for wiring an oil pressure warning light and also replace the existing ignition/indicator/main beam warning lights.

 

Ideally looking for ones that are bezelled and will fit inside the existing holes. I'm competent via a soldering iron & remember a bit of my O level electronics but am just plain lazy and want to plug and play!

 

I'm aware that Farnell/Europe/RS etc will probably stock what I want, so any product codes of items that people have used will be gratefully received.

 

Cheers,

 

Kevin Thomas

kevin.thomas@bigfoot.com

www.7gallery.co.uk

 

[SvenDriver]

If you have a farnells catalog or a maplins nearby then this is easy!

 

Just buy yourself any old Red LED for a few p and a 1/4W resistor to put in series with it.

 

The sums are:

1. LED has a forward voltage and current rating (read the spec.).

2. Assume you want 2/3 of this current (keep it cool).

3. Assume your 12v car battery is over-voltage - maybe 13v

4. use R=V/I where I is current in 2. and V=13-LEDFwdVoltage

 

You should have change from a quid.

[V7 SLR]

There's no such thing as a 12V LED. All LED's are current devices and most require a current limiting resistor for a 12V supply. What has become known as a "12V LED" is one which has a built-in 1K (or thereabout) resistor, but I wouldn't worry about that.

 

Have a look in RS at the 10mm LEDs. I've replaced all my dash lights with the clearwater type, that is, the type that look clear until they are lit. Some are "12V" types and some aren't. In practice I've added an external 1K resistor anyway because they are bloody bright when aimed at your eyes, even in daylight.

 

I don't have the part numbers, I'm afraid. I worked it out whilst standing at their trade counter.

 

Bevels are available later in the same section of their catalogue. 10mm LEDs and bevels fit quite nicely in the standard-cut holes. Be aware two things:

 

1. The ignition light has a diode to ensure it only comes on when the battery provides the voltage, i.e. when the alternator isn't.... i.e. when the engine is stationary. This isn't needed when using a LED as it is already a diode.

 

2. The indicator light requires 2 diodes attached to one leg of the diode because the two supply wires supply a voltage depending upon which way you are indicating. I haven't explained this very well. My phone number's in the AO page. Give me a call and I'll try to explain it better.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[Andrew Dent]

Farnell do a part that you can wire directly across the 12v supply. The resistor is inside the unit and as such you need not worry about it. They also have some very high intensity 10mm LEDs that are excellent as warning lights. If you want to make them even brighter, take the thing apart and add an other resistor across the existing one.

 

A green one can be used if you create a little diode network with suitable diodes so you get a bright clear indicator light.

 

4 wheels on my 7