# Difference between magnetic and electronic dimmer?



## BBQ

As I understand it the cheaper dimmer, produces an output like this










Which is OK for an incandescent lamp but not a magnetic transformer. The constant instant 0 volt to full volt spike cause inrush current each time overheating the transformer. 

The better dimmer produces a wave more like this










A slow rise and sharp fall.


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## SparkYZ

A dimmer essentially shuts off the power to a luminaire each time the sine wave changes direction right? A cheaper (magnetic) one shuts it off before the peak, and a better one shuts if off after the peak...

So you could use a low voltage electronic dimmer on a magnetic fixture, couldnt you? It's kinda like a better, smoother, power supply (wrong wording, I know)


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## Jackomo

This might answer your question:

http://www.lutron.com/ResourceLibrary/362219.pdf


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## Dennis Alwon

SparkYZ said:


> What is the output difference on a low voltage magnetic dimmer, as opposed to an electronic low voltage dimmer?


It has to do with the transformer that you are dimming. If you have a low voltage light that has a magnetic trany then you would use a LV magnetic dimmer. If the trany is electronic then use an electronic LV dimmer. Now there are some LV electronic tranies that can be used with a standard dimmer but generally it will state that on the trany or somewhere. I have seen some WAC electronic tranies that did not need an electronic dimmer.


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## Jbird66

Dennis Alwon said:


> Now there are some LV electronic tranies that can be used with a standard dimmer but generally it will state that on the trany or somewhere. I have seen some WAC electronic tranies that did not need an electronic dimmer.


The question I always had with this:

The transformer "may" said you can use it with a standard dimmer but I have never seen a standard Incandescent dimmer say you could use it with any electronic transformers. It comes down to a "listing" question. 

Its kind of like GFI testers. Sure the GFI tester is listed to test GFI's but most GFI's are only listed to be "tested" by pushing the test button on the device..

And yes that is a fun question for the AHJ.


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## Dennis Alwon

Imo, the dimmer does not have to list every type of transformer or light that it can dimmer, but I may be wrong. If it states do not use with LV lighting that would be different. I have never had an issue with a Lutron ariadni dimmer on a lv fixture that stated it can be dimmed from a standard dimmer.

We can see this issue everywhere-- Siemens makes a breaker that will fit SQ. D and is listed for it but the panel states listed for sq. d breakers.... What do you do.

All standard incandescent recessed cans I have seen that I have seen are listed as incandescent luminaires. Now the CFL bulbs say they are listed for all cans????? Same issue.


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## Electric_Light

If the dimmer and load are not matched for the application, you may experience malfunctioning or limited dimming range.

A two-wire fluorescent dimmer meant for Lutron TuWire and Philips-Advance Mark X actually works just fine with incandescent, but you'll have a disappointingly narrow dimming range. 

Other way around, you'll experience flickering and limited dimming range. The flickering will lead to premature lamp failure.

The reverse-phase design which rises from zero, then cuts off at set point is designed specifically for electronic low voltage transformers that call for it. MLV transformers do not use reverse phase dimmer, though some have neutral for more stable operation.


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## Shorty Circuit

Dennis Alwon said:


> We can see this issue everywhere-- Siemens makes a breaker that will fit SQ. D and is listed for it but the panel states listed for sq. d breakers.... What do you do.


Stick with the Squre D breaker. Even though the Siemens breaker is listed, installling it in a Square D panel de-lists the panel by violating the limits on its UL listing.


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## Shockdoc

Shorty Circuit said:


> Stick with the Squre D breaker. Even though the Siemens breaker is listed, installling it in a Square D panel de-lists the panel by violating the limits on its UL listing.


I actually have about a dozen GE40 amp DP breakers made for SQ D QO . bought them at a garage sale for $10.


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## paulgarett

can a dimmer work with both electronic and magnetic transformers on the same switch leg?
I want to replace bad magnetic transformers for low voltage can lights with electronic transformers since they are cheaper and plentiful at the supply house. But would the dimmer work for a combination of both magnetic and electronic transformers?


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## Going_Commando

Phuck the UL with a rusty spoon.


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## ngsafety

Magnetic dimmers use onward phase dimming, and electronic dimmers use overturn phase dimming

*link removed*


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