0-12v DC dimmers for landscape LED's ?

[TundraSonic]

Our landscape lighting is using fixtures from CAST that are supposed to be dimmable LED's. I'm guessing that we'll need 0-12v (or 13v, 14v or 15v) DC for these but I'm still trying to verify this w/ CAST (their local rep is apparently rather clueless). Is anyone aware of a good solution for controlling these w/ C4?

Thanks,

[nwanerka]

Do the landscape lights work off of a transformer that then plugs into a 120 volt outlet? If so you can use a c4 plug in modular. One of the dimmable ones

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[brantlmcdonald]

You can’t use the C4 plug in dimmer.

 

You need forward-phase dimming (MLV); the plug in dimmer is reverse phase.

 

You can use either the forward-phase or adaptive-phase dimmers from C4. Hardwire the transformer to a circuit extending from the wall dimmer.

 

 

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[TundraSonic]

I was incorrect on the DC. These fixtures appear to me to be AC (https://cast-lighting.com/landscape-products/cast-classic-engineered-wall-light).

I'm hoping to avoid the transformers if possible. They are expensive, take up a lot of wall space and if downstream of the dimmers we'd need 7 of them (one per circuit). 

@brantlmcdonald, are you saying FPD because a transformer rather than LED would be downstream? My understanding is that LED's don't like FPD and are much happier w/ RPD.

Thanks,

[Brownbatsbreath]

If your lights are 12v, you’ll need a transformer. 
If you want to dim it, consult with the transformer manufacturer on the best type of dimmer to use and install the corresponding C4 dimmer. 

Please note, 0-10v dimmers are made for sending a 0-10v dimming signal to drivers/ballasts that are made to accept that signal. They are NOT meant to supply voltage directly to your low voltage light fixtures.  

[TundraSonic]

Thanks. You can't use a 120v dimmer and set a max of 12v (or 15 or 18?)?  In theatre and rock&roll that was quite common.

[brantlmcdonald]

I was incorrect on the DC. These fixtures appear to me to be AC (https://cast-lighting.com/landscape-products/cast-classic-engineered-wall-light).
I'm hoping to avoid the transformers if possible. They are expensive, take up a lot of wall space and if downstream of the dimmers we'd need 7 of them (one per circuit). 
@brantlmcdonald, are you saying FPD because a transformer rather than LED would be downstream? My understanding is that LED's don't like FPD and are much happier w/ RPD.
Thanks,

Yes, I knew they would be AC. You cannot avoid the transformer.

Forward phase dimming because you will have a magnetic transformer.


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[brantlmcdonald]

Thanks. You can't use a 120v dimmer and set a max of 12v (or 15 or 18?)?  In theatre and rock&roll that was quite common.

No.


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[TundraSonic]

Thank you all!  I may see what I can do for something downstream of the xformer then. 

[brantlmcdonald]

Thank you all!  I may see what I can do for something downstream of the xformer then. 

No, you want to go upstream with the forward phase dimmer. I don’t know of any 12v dimmer that you’ll be able to integrate into C4. 12v AC dimmers do exist, but it will be manual control.

Just so we’re clear, a dimmer switch does not change the voltage. If you try to put a 120v dimmer on those LED’s and not use a transformer, you will still have 120v, and you will damage the lamps.


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[Cyknight]

States they can be AC OR DC.

If DC is an option, DMX control may be an option

[TundraSonic]

Thanks. How would you do this w/ DMX to DC based fixtures? 

On 9/8/2020 at 9:06 PM, brantlmcdonald said:

Just so we’re clear, a dimmer switch does not change the voltage. If you try to put a 120v dimmer on those LED’s and not use a transformer, you will still have 120v, and you will damage the lamps.

Yes. True. Forgot about that. (We would frequently stick a single 28v PAR36 aircraft landing light on a dimmer and simply limit them to 22% output and they'd work great. Now that you mention it, I'm not sure why. We could also briefly take them up higher but they'd pop pretty quickly.)

Doing the dimming upstream of the xformers will require the purchase of multiple xformers as well as multiple dimmers ($$'s) along with wall space for them. Doing it downstream should require only one xformer. I assume these would be reverse phase dimmers.

[TundraSonic]

Thinking about it (it's been years since I've done much with analog electrical so lots of cobwebs to work through), most or all LED lamps are likely OK with DC? So long as all of the internal electronics are downstream of the rectifier. I'd guess that nearly all of these have a small xformer (if needed) followed by a rectifier and then everything else.