LED dimmer for Jay

[SternWake]

Dimming LEDs is not hard with a PWM dimmer.

I've used the following product on my LED lighting:

 http://www.amazon.com/Dimming-Contr...qid=1453844206&sr=8-2&keywords=pwm+led+dimmer

While the plastic case is rather large, the electronic guts within are quite small.  I have removed these and installed them inside individual reading lights and also put one on my main lighting switchboard as it can handle 8 amps.

Do note there are some regulated LEDS which will not respond to a PWM dimmer.  In general this will be the LEDS with advertised wide input voltage ranges like 12 to 24v or 5 to 32 volts.

LEDs can make radio noise and knock out some TV stations or AM radio.

Some LEDs when dimmed can make an audible whine which can be annoying.

Note the product above is 8$ or so but are an American seller for quick delivery and it shows pics of the electronic guts.  If one wants to wait 3+ weeks for the slow boat from China they can be had for as little as 2.21$

I've also used PWM motor speed controllers to dim LED lighting, and I've used the PWM LED dimmer to lower computer muffin fan speeds as well.

The amp draw at 80% brightness or 80% speed is more than just a 20% reduction in current, so these can also lower battery consumption to some degree also.

 

[FALCON]

Another option for an LED PWM Dimmer is the Kick Lighting KR6. I have one of them and it works well so far. I think it's basically the same thing as the one Stern Wake linked, but it is much smaller and probably easier to do a clean install with. It costs a bit more though and it is harder to buy because the Kick Lighting company appears to only sell them directly in bulk. I bought mine on ebay for $18.

http://www.kicklighting.com/PWM-dimmer-switch-for-LED.htm

 

[SternWake]

I like that the KR6 has a heatsink and a click to off feature on the potentiometer. Mine do not click to off, in fact when twisted all the way CCW the light comes back on at full brightness after being off. I still use switches to turn them completely off.

I ran a 12v 3.9 amp fan on both the PWM dimmer I linked, and a 10 amp motor speed controller.
This specific one, which I do not recommend:

http://www.amazon.com/GERI-Motor-Sp...9&sr=8-74&keywords=pwm+motor+speed+controller

The 10a MSC has finned heat sinks and they got burning hot throttling down the beast of a fan, but the PWM led dimmer did not, and has no heat sinks anyway..


I'm not sure what is going on with regards to that, but an electronics whiz friend of mine ordered one and looked at the guts of the linked dimmer and said the components were well matched and well made, and he promptly ordered 5 more from China.

The 25khz refresh rate of the MSC linked above should reduce the audible( to humans) whine that PWM will cause on some motors or LEDs, where as most pwm msc's are ~14khz which humans can hear.

I've not run the PWM dimmer anywhere near 8 amps for any length of time so i do not know how long it will last passing that much current. All my LEDs draw less than 1.5 amps

Double check the polarity before connecting, otherwise instant smoke.

 

[WheelEstate USA]

SW....Thanks for that info in response to my text today.
I'll order a couple so I can do a fan as well a the LED strip.

 

[SternWake]

Your welcome. I had too much info to relate via text message.

 Sorry I did not have an extra PWM dimmer/ MSC to gift you when we met, I just found my extra MSC, but the LED dimmer not getting scorching hot taming the ~4 amp fan leads me to believe it is the better choice anyway.


The 10K ohm potentiometer wires can be extended and the pot located where most convenient too.

Next time I gots some spending $$ I might pick up a few more of the LED dimmers.  I've got some ideas for a ridiculously bright task light that would need taming for regular use.

 

[WheelEstate USA]

What happened to the days when Radio Shack was manned by electronic geeks? 
Neither of the guys I talked to had the slightest idea whether it would work the way I had in mind.
I asked if they knew electronics and neither did.

 

[MikeRuth]

What happened to the days when Radio Shack was manned by electronic geeks? 
Neither of the guys I talked to had the slightest idea whether it would work the way I had in mind.
I asked if they knew electronics and neither did.

Those days are loooooong gone!!!! SAD

Mike R

 

[mikEXpat]

Should I be concerned that my LEDs are going to cause interference with my TV or radio?

 

[SternWake]

Should I be concerned that my LEDs are going to cause interference with my TV or radio?

It is certainly a possibility.

It can be negated to some degree by tightly twisting the power leads to the LED and putting some snap on ferrites close to the LED and the  powersource.

Another trick is some sort of capacitor between the + and - as close as possible to the led itself.  That is beyond my pay grade as to what  value capacitor.

Some LEDs are worse than others in this regard.  If the LED is one of those  12 to 24 volt range ones, or if it does not care about + or -, then the interference seems worse.

how big a deal is it?  It seems to happen to the VHF low stations and the lower range of UHF on my TV.  Actual channels 7 through 19 seem the most effected for me

I don't know about the am or FM radio.  Their overwhelmingly annoying  commercials fill me with blind, machete swinging rage, so I avoid listening to radio.

The mute button on my remote is similarly mushed, but thankfully still operational

 

[WheelEstate USA]

I have yet to to much with my LED strip lights with the exception of a couple short pieces of 3 or 4 for evening use. The long ones are just so bright indoors, yet not great for reading.
The LED fixtures used for reading, etc do not bother the radio or Tv.

 

[SternWake]

My red LED strip lights do not seem to emit any RFI, that I've ever noticed.

The OTA TV channels in one's location plays a huge part in IF the LED will cause RFI interference on any particular channel.

In my Area 7-13, VHF hi is still used and these channels are most susceptible to RFI from my LEDs.
My PWR+ laptop dc to dc 'car adapter' knocks out channel 8, which is my strongest station. That is more annoying to me than the LEDs taking out channel 7 or 11 or 19, as I can just turn the LEDs off, but if the laptop battery is dead, and I want to watch channel 8, I'm screwed.

My 115 ac power supply for the laptop on the inverter also knocks out channel 8. Just turning on the inverter makes some strong channels weak and weak channels disappear, if they are VHF hi 7-13 , upto UHF low, channel 19, which is 69.1 in my location.

RFI is annoying, certainly.

 

[mikEXpat]

Thanks for the replies. Sounds like this is one of those things not worth thinking about.