LED Dimming (OT)

[rick.curl]

Well- it's probably too late, but it occurs to me that given the 220 mains on your side of the big pond, and the LED voltage of 132-201V, there is an easy way to make a driver.

The attached schematic takes advantage of the capacitive reactance of a metallized film capacitor. It should be rated 350 volts or higher. It's important that it be a metallized capacitor and NOT an electrolytic, since it will see AC voltage. I'd start with about 1uF.  Higher capacitance makes the LEDs brighter. The bridge rectifier obviously converts the AC to DC. R1 limits the inrush into the rectifier and filter capacitor C1. C1's purpose is to eliminate flicker. C1 should be an aluminum electrolytic, maybe 10 to 50uF, with a voltage rating of 350 volts or better. R2 is only needed if there's ever a possibility of the LEDs being disconnected and reconnected while the driver is powered up, since the voltage across C1 will fly up to more than 300 volts in the absence of a load. R1 and R2 are not critical, but you could use 33 ohms 2 watts as a starting point. 

Sounds like you've already got this solved.  Sorry to be late coming up with a possible solution.


-Rick

[ken_k]

Well- it's probably too late, but it occurs to me that given the 220 mains on your side of the big pond, and the LED voltage of 132-201V, there is an easy way to make a driver.


-Rick

Hi Rick
I believe your solution is technically correct.
My guess is that it may be illegal in the UK, one would need to refer the the regulations.
Voltage spikes with a fast rise time will pass through C2, allowances need to be made for this.

Ken

[RGV250]

Hi Tim,
I have one which works similar https://www.tlc-direct.co.uk/Products/GLCPL24CT.html
From the instructions you can set the colour temperature like so, might work for yours. It also has a selector switch which I used.

Colour Temperature Adjustment
The colour temperature may be set by means of a switch on the rear of the luminaire. The
options are:
WW (warm white), CW (cool white), DL (daylight) and SWITCH
The SWITCH option allows the colour temperature to be controlled from an external
wall switch. Switch the luminaire off and on again repeatedly until the desired colour
temperature is achieved. - then switch off and leave off for at least 5 seconds to save the setting

Bob

[TimB]

Thanks Bob

Another feature I did not know was there. Yes it works on the new driver.

Tim