LED Dimming ?

Hi Nigel,

We have used a "blue" plastic leaf you can buy from a newsagent - A4 size, and cut it in a spiral shape which can be held over the LED light buy glueing some velcro so as to be able to attach/remove as needed. Still provides a good reading light while giving off a soft blue glow outside.

Terry

Hi Nigel,

You must have good eyes, or else there has been a vast improvement in LED's in the past few years. Most people complain that they are not bright enough.

LED's output brightness is a function of voltage. If you want to make a simple regulator (dimmer) the construction is very simple & the parts are cheap.
You need to make a trip to Jay-Car, Dick Smith or Tandy & purchase a 317T adjustable regulator (about $2), a 220 ohm resistor, a 2000 ohm potentiometer, and a suitable knob. The lot should cost about $5-$6.

The ‘input’ pin of the 317T is connected to +12v. The ‘output’ pin is connected to the 220 ohm resistor and to your LED. The other end of the 220 ohm resistor is connected to the top terminal of the 2000ohm potentiometer. The bottom terminal of the potentiometer is connected to -12v (ground). The centre terminal of the potentiometer is connected to the ‘adjust’ pin of the 317T.
Pin connections of the 317T are; looking at the device face up, pins left to right are ‘adjust’ ‘output’ ‘input’

This is about as simple as you can get, have a go even if you have never played with electronics before. At worst you are only risking a few dollars, & it won’t go ‘Bang’. The staff at the store will also help with pin identification and any other help you need.

Good luck

Neil

Search ebay for item number 280504861024.

LEDs are current dependent devices and require a variable current controller to vary the light output. The ebay item above does not say how it works but I assume this would be the case. A variable voltage device will only work on a LED that has a resistor in series for current limlting.

Most LED lamps assemblies these days are current limlted which allows them to be connected to a wide range of voltages. This has the added advantage of being more efficient with less heat loss.

Our van is entirely lit by MR16s flush mounted in the ceiling. The bed lamps are also MR16s and are just warm to touch. A lot of them are required for good light distribution but are functionally excellent.

Unlike fluros you can guarantee they work every time. I do have fluros for external lighting as I have not found a suitable LED alternative.

I'm amazed and very appreciative for the ingenuity and expertise you've provided.

Not only very helpful but educational as well.

It looks like next trip I might avoid the, " aren't you going to sleep tonight gibe'.

Thanks again for your help.

Regards, Nigel.