Dimming 12 Volt lights

[johndoe]

What's the best way to dim a set of 12 volt cabin lights..
I have approx 7 lights wired to one switch... way to bright
when on.. and too dark when off

 

[Silvertip]

Re: Dimming 12 Volt lights

Any store that sells auto accessories usually have a selection of automotive switches, wiring, fuses, lights, etc. Look for a rheostat style heater motor speed control switch. These usually have a round knob and are continuously variable with a full on position. You can replace the original switch with this one although the wall plate would likely need some slight modification. Rheostat type switches can get hot so it needs to be mounted where the coil won't ignite anything combustible. These switches are very inexpensive.

 

[bruceb58]

Re: Dimming 12 Volt lights

They are available but expensive. They have a FET in them with a circuit that switches the voltage on and off with an adjustable duty factor. I have seen them for less than $100.

There are some cheaper rheostat ones but they will get very hot with the number of lights you are running.

Here is one of the cheaper ones:
http://www.outerbanksoutfitters.com/product/196976914.htm

here is the better way:
http://www.boatfix.com/cart2/Scripts/prodView.asp?idproduct=7238

You need to also get a momentary spdt switch for this one.

 

[johndoe]

Re: Dimming 12 Volt lights

Similar to this....
but yours has better price...

this one doesn't require spdt switch.. why, I wonder??

http://www.fisheriessupply.com/onli...ode+matchpartial+rel+Inactive/act/A01/Ntk/All

 

[bruceb58]

Re: Dimming 12 Volt lights

It is the exact same unit. it will need the switch.

They have the switches near the bottom.

 

[johndoe]

Re: Dimming 12 Volt lights

yea, i thought so....
my mistake...

Why a momentary... why can't I use the existing on off switch and use the dimmer downstream of it...

 

[bruceb58]

Re: Dimming 12 Volt lights

The way this works is that every time you hit the momentary it dims or brightens depending on a sequence. When you turn it on, it goes to the last brightness setting.