Dimmer Advice

[Jerry and Ce]

Is it possible to fit some kind of dimmer to a mains transformer powered 'net of lights'?

Thanks for any help. Jerry

[Andy Champ]

Maybe :)

- What kind of power supply? Just a transformer, or something clever?

- What kind of bulbs?

Andy

[Palindrome]

If this is a simple mains transformer connected to a load of small incandescent lamps, and not something more high tech ..eg using LEDs, or able to produce different effects, then yes, it is very easy to fit some kind of dimmer.

Here are some options:

Look at the voltage and current output of the transformer - it should be written on it. Buy a power diode of double that voltage and current (eg from Maplins. Wire that in series with the *output* of the transformer, with a switch across it. When in circuit, the diode will dim the lights. when the diode is shorted out, the lights will be on full.

If you want more steps, take the voltage and current details to an electronics shop (such as Maplins) and get a multi-output power supply capable of producing that voltage and current. Use that to replace the transformer supplied with the lights. That will give you as many brightness steps as there are suitable voltage output settings on the power supply.

If you want continuous variation of brightness, get a variable output supply to replace the existing transformer. Or, fit a suitable rheostat in series with the lamps. If you want to know what type to get, write again with all the details from the transformer.

A mains dimmer on the input to the transformer *may* work. However, the options above are prefereable. The current drawn by the net of lamps may be too low to allow a normal mains dimmer to work reliably. Plus, it is not normally best practice to connect a dimmer to a transformer.

What is best practice is to use a thing called a Variac. One of those, with a suitable rating, and with the lighting trasnformer plugged into it, will smoothly dim the lights from off to full on.

However, if the "transformer" also allows light effects to be produced, then one or more rheostats in series with the lamps is probably the easiest solution. Again if you write back with details from the "transformer", it should be possible to suggest what rheostat(s) to buy.

Cost? Depends on what you go for. A diode plus switch =

[Jerry and Ce]

Thanks for your advice. I was hoping for something that would be cheap and 'plug and play'. It's not something I want to spend much on, and custom wiring is beyond me. Thanks again though. Jerry

[Andy Champ]

Jerry, send us a link to the "net of lights" somewhere on the web so we can see the spec., we may be able to advise further.

Andy

[Jerry and Ce]

Hi Andy, It's a few years old and I can't find one showing similar transformer. Not keen enough to hunt longer, but I appreciate your help. Jerry