Model Railway Forum

Hi, i am looking to generally have the facility to dim the different area's of the layout of things like street lights on one, buildings on another & wondered if i am best dimming the 240v transformer side or preferably via a Potentiometer on the 12v side. If on the 12 volt side, what sort of ohmage size would i need to cover each area on any one circuit, there could be between 10 & 30 leds 3mm & 5mm. Or would something like this speed controller work ok?
https://www.ebay.co.uk/itm/1pcs-PWM-DC- ... SwCrtcc5NU

Thanks

Mod edit. Title amended.

That should work but watch the total current draw of the leds.

Thanks, Odley enough, i found one with a very similar spec at 5amp instead of 2. So ordered the 5amp ones

On mine I used a veritable voltage module that can go from 3 to 12 volts so because they all have a resistor attached will turn them from full to off.

It worked well for me.

Will try and find a link to the one I used.

Paul

This is the one I used https://www.ebay.co.uk/itm/LED-display- ... 3590832365

Paul-H wrote: ↑Sun Mar 24, 2019 9:03 am This is the one I used https://www.ebay.co.uk/itm/LED-display- ... 3590832365

Just to make sure that others don't get confused, this, as you said in post #4, is a step down voltage regulator not to be confused with the PWM module linked to in the OP's opening post. Whereas this provides a linear (straight line) DC output, the former's output is a square wave that is adjusted by Pulse Width Modulation (PWM) by varying the on/off cycle duration which is then interpreted by the load (usually a motor) as an "average" DC level. I only add this as the two modules may look similar to the uninitiated.

I power my ‘station’ lights etc from the twin speed knob outputs of an old analogue controller. If you happen to wire them up backwards then its a simple fwd/rev swtich over to fix it.

So do I.

Varied answers as expected, but for what it’s worth I use PWMs similar to this linked in post #1. Can be used for fine control of turntables as well.

I use a controller for that as well.