Maker Pro
Maker Pro

220v LED DIMMER??

KrisBlueNZ

Sadly passed away in 2015
Nov 28, 2011
8,393
Joined
Nov 28, 2011
Messages
8,393
I just need an 300v switching voltage regulator or power supply (adjustable down to 100v). it makes no difference if it's DC or AC i can easily strip away the rectifier bridge and capacitor circuit.
Do you mean that you would modify every LED light bulb that you buy, to remove the capacitor and bridge rectifier?
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
I want to have at least 2 dimmable lights the one i reconstructed and another one.

Steve if you mean that it is dangerous to put it inside a wall box because of the heat, then i would tell you that i have a commercial dimmer with an incandescent lamp and it VERY HOT, much hotter that the FET. If i use a heatsink for the fet it will be almost cool. I don't have any insurance or anything anyway and i am thinking to put a thermostat so it will be ok. Thanks for your concern
 

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
Huh? Is it an old 'Rheostat' design? They were high power variable resistors that belched out copious amounts of heat. It was a miracle that they were ever approved by UL or any safety compliance agency. I think they'd re-purpos as a space heater or a toaster though! :D

Chris
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
Here is the circuit without the confusing arrows. :D
 

Attachments

  • dimmer circuit simple.jpg
    dimmer circuit simple.jpg
    57.8 KB · Views: 5,391

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180

If you look more closely you will see that all the dimmers which you linked are for DIMMABLE LEDS ONLY, they don't work with mine LEDs
"Leviton Decora SureSlide dimmers provide smooth, slide-action, full-range dimming for incandescent and dimmable LED and CFL lamps."

I don't like dimmable leds because most of them are spot and are low wattage mostly 12w max. I need 20w+ they are also expensive
 
Last edited:

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
as you say there are 3 separate circuits 2 "power supply" pcbs gives power to 5 led pcbs
each and the other one gives power to the other 2 led plates and the center circular led plate

This quote is from one of your posts early in the thread. How many R1s' (10R) are there? Unless my calculations are way off R1 dissipates about 100mW.

Chris
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
This quote is from one of your posts early in the thread. How many R1s' (10R) are there? Unless my calculations are way off R1 dissipates about 100mW.

Chris

As there were originaly 3 ac to dc "power supply" pcbs in the lamp, there is R1 on each one so 3R1s
 
Last edited:

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
As there were originaly 3 ac to dc "power supply" pcbs in the lamp, there is R1 on each one so 3R1s

I asked because I was pondering a 3 gang pot wired as a rheostat in series with R1A,B,C. The logistics of this may not be convenient though.

Chris
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
But then the pot will have to dissipate a lot of power i tried it before with a 2w pot and it got burned instantly
Well i actually tried it at the ac but it was still in series with the leds
 

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
Well, I don't know what R value your pot was. I was not thinking of a high value. I really don't like that solution anyway as it's yet another linear concept. It was more like thinking aloud. My good sense little voice should have said shut up until you have something viable. :D

Chris
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
It's ok to think out loud because even if your idea doesn't work it could give someone else an idea.
I never tried it the way you propose i only tried it in the ac wires going from the main to the "power supply" pcb of the lamp (the one with the 2 gray capacitors)
 
Last edited:

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
Let's back up for a moment and review a few things. A common Triac dimmer is actually a form of PWM because it slices off a piece of each pos & neg cycle. Which, in effect shortens the on time that the load is receiving current. It doesn't work well for LEDs because LEDs are fast and there's no hot element that's still giving off residual light during it's off periods. After all, a filament has to cool before our eyes can perceive a difference.

Since conventional PWM circuits are used to dim LEDs in 12V systems here's a thought....Have you considered using a conventional 12V 555 PWM circuit powered by a wallwart? The PWM output of the 555 would drive your FET while your 240v LED string would be connected in the Drain circuit.

Of course the above scenario would require removing all the caps in your current configuration except the filter cap on the output of the bridge. That cap would have to be increased to about 100uF. You will also have to calculate LED current and possibly (probably likely) add more LEDs in series as well as replace the limiting resistors. This circuit would most certainly deserve a SB fuse too. It may also require a series resistor on the output of the bridge to limit the inrush current to the filter cap when it's first turned on.

See if you can sketch up a schematic of this concept on your own. If not I'll draw and spice run one for you. Actually, I started drawing this up yesterday but I ran into a snag. I've never liked the POT symbol used in my Tina Spice because it is so damn big! Sooo, last night I decided to modify the symbol. Big mistake, as in many things 'computer' everything turned to sh!t after that. I finally straightened the mess out after many hours of wanting to use my laptop as a Frisbee!!!! :eek:

Chris
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
This is a easy and good solution although it will require me to destroy any lamps that i need to make dimmable like i destroyed the one in the photo (i had to cut the casing of the lamp to get the circuit out :D but if there is no other way ...

will THIS work as an pwm for the fet?
 

Rleo6965

Jan 22, 2012
585
Joined
Jan 22, 2012
Messages
585
Let's back up for a moment and review a few things. A common Triac dimmer is actually a form of PWM because it slices off a piece of each pos & neg cycle. Which, in effect shortens the on time that the load is receiving current. It doesn't work well for LEDs because LEDs are fast and there's no hot element that's still giving off residual light during it's off periods. After all, a filament has to cool before our eyes can perceive a difference.

How about we still use the a working PWM working circuit and place an inductive load to its 220 AC output. This will solved LED problem with PWM control voltages.

AC output will therefore be reduced and together with LED brightness.

I'm not really expert in Triac circuit. Just wondering if "inductive load will work.
 

Attachments

  • PWM Inductive Load.JPG
    PWM Inductive Load.JPG
    34.3 KB · Views: 4,191

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
I was thinking of something like this. I took the 555 PWM from here.

http://www.reuk.co.uk/LED-Dimmer-Circuit.htm

They're running the 555 @ 250Hz but I jacked it up to 2.5KHz here.

Please note that my opinions about circuits like this connected directly to the mains haven't changed. I still feel uncomfortable with it.

Chris

EDIT: This schematic has been modified to include notes of dangerous voltage potentials!
A second schematic and scope plots were also added. They describes the nodes between where these dangerous voltages are located.
 

Attachments

  • 555MainsLedDimmer.JPG
    555MainsLedDimmer.JPG
    48.5 KB · Views: 874
  • MainsBridgeRect.JPG
    MainsBridgeRect.JPG
    57.5 KB · Views: 1,779
Last edited:

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
How about we still use the a working PWM working circuit and place an inductive load to its 220 AC output. This will solved LED problem with PWM control voltages.

AC output will therefore be reduced and together with LED brightness.

I'm not really expert in Triac circuit. Just wondering if "inductive load will work.


OK i have no idea what the inductive load will do. Will it smooth out the voltage or something like that?
 

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
I was thinking of something like this. I took the 555 PWM from here.

http://www.reuk.co.uk/LED-Dimmer-Circuit.htm

They're running the 555 @ 250Hz but I jacked it up to 2.5KHz here.

Please note that my opinions about circuits like this connected directly to the mains haven't changed. I still feel uncomfortable with it.

Chris

Ok this will work i can't connect ground to - though.

I still don't understand why the led can't work of DC? what's the role of the 2 Brown AC capacitors?

And if i may ask what program did you use to sketch this diagram?
 

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
4,960
Joined
May 8, 2012
Messages
4,960
Ok this will work i can't connect ground to - though.

I still don't understand why the led can't work of DC? what's the role of the 2 Brown AC capacitors?

And if i may ask what program did you use to sketch this diagram?

Note: You will find large font and large red font in this reply. When I do this it usually indicates DANGER!

Go back to my last post. I've edited the schematic to include vital information regarding dangerous node potentials. I've also included a second schematic with plots. That said, I'll be posting another schematic that utilizes an Opto-Isolator. It will completely isolate the 12V circuit from the mains but the negative node of the HVDC supply potential (VF2) will still be dangerously above earth ground as shown here. This is why utilizing an Isolation Transformer is the only safe way to mess with the mains!! To be sure I don't advocate this circuit or any circuit that does not provide total isolation from the mains! This circuit was provided for its educational value ONLY!

7690d1364745526-220v-led-dimmer-mainsbridgerect.jpg


My schematics are drawn and simulated in Tina Classic.

Chris
 
Last edited:

BlinkingLeds

Feb 23, 2013
180
Joined
Feb 23, 2013
Messages
180
I always use 1:1 transformer (isolating?) and wear thick rubber gloves when working with high voltages sometimes i stand on 16mm plywood. If i work with voltages exceeding mains voltage i try to work only with my right hand. I learned all that from a friend that works at the power company. He also suggested getting hv gloves but i can't work with them.
 
Top