Hi guys
I'm new to the forum but a bit of a vetran to electronics
Recently I've been repairing disco lights and amplifiers (I also run a mobile disco amongst other things)
I've become interested in upgrading disco lights to LED - in particular upgrading low wattage LED fixtures to high wattage
I have a second hand LED light fixture here which has the right sort of optical path (in other words I will not obstruct the optics with a large LED/heatsink and has quite a bit of room in the casing for the additional power supply
What I want to do is replace the existing RGB LED (I think it is a 10W one) with a 100W RGB LED
This raises a few questons in my head that I am not sure how to answer....
Firstly I am wondering if a 100W RGB LED is actually 33W red + 33W blue + 33W green (or some similar combination)?
The data for the LED I was thinking of fitting is this one here http://www.ebay.co.uk/itm/New10W-20...t=LH_DefaultDomain_3&var=&hash=item233cc9862f
Which tells me 100W 32-35V 3000mA Genesis's 30MilChip
I know the 100W LED needs a driver - and they are easy enough to get for a single colour LED but how about the RGB one? I mean to say - a 100W constant current driver won't work because the current would vary depending on which combination of colours are actually illuminated?
I had a look at the drive to the existing 10W LED on my scope. As I would expect there is a common anode supply of 12V then each colour is being driven (by what looks like a FET though I didn't look at the device number/datasheet) and it looks like it is using some sort of pulse drive, but the frequency seems too low (approx 13mS or about 80Hz) which is much less than I would have expected to see in a PWM drive circuit, and the duty cycle looks all wrong too (almost all on)
The vertical scale is 5V/cm (center line is 0V) - see attached pic.
The existing disco light unit switches the RGB colours on/off - it does not dim or fade the colours.
I attach a photo taken from my scope for you to study. That's not actually PWM is it?
OK so I can see I have a few issues to get over: My options would seem to be:
1. Interface the existing (PWM?) drive to switch three higher power FETs so I can control the 100W LED in the same way the 10W one is currently being driven?
2. Buy some sort of off-the-shelf 100W RGB LED driver that let's me switch the colours on and off using logic level (TTL?) which I whould be able to interface from the microcontroller on the existing driver board
3. Build my own driver as speciifed in option 2
4. - over to you guys.......
Regards cooling - the existing light has an external ront mounted heatsink. I was hoping to replace this with a CPU Heatsink/fan as these seem quite capable of dissipating some high amounts of wattage
All help much appreciated
Rich
I'm new to the forum but a bit of a vetran to electronics
Recently I've been repairing disco lights and amplifiers (I also run a mobile disco amongst other things)
I've become interested in upgrading disco lights to LED - in particular upgrading low wattage LED fixtures to high wattage
I have a second hand LED light fixture here which has the right sort of optical path (in other words I will not obstruct the optics with a large LED/heatsink and has quite a bit of room in the casing for the additional power supply
What I want to do is replace the existing RGB LED (I think it is a 10W one) with a 100W RGB LED
This raises a few questons in my head that I am not sure how to answer....
Firstly I am wondering if a 100W RGB LED is actually 33W red + 33W blue + 33W green (or some similar combination)?
The data for the LED I was thinking of fitting is this one here http://www.ebay.co.uk/itm/New10W-20...t=LH_DefaultDomain_3&var=&hash=item233cc9862f
Which tells me 100W 32-35V 3000mA Genesis's 30MilChip
I know the 100W LED needs a driver - and they are easy enough to get for a single colour LED but how about the RGB one? I mean to say - a 100W constant current driver won't work because the current would vary depending on which combination of colours are actually illuminated?
I had a look at the drive to the existing 10W LED on my scope. As I would expect there is a common anode supply of 12V then each colour is being driven (by what looks like a FET though I didn't look at the device number/datasheet) and it looks like it is using some sort of pulse drive, but the frequency seems too low (approx 13mS or about 80Hz) which is much less than I would have expected to see in a PWM drive circuit, and the duty cycle looks all wrong too (almost all on)
The vertical scale is 5V/cm (center line is 0V) - see attached pic.
The existing disco light unit switches the RGB colours on/off - it does not dim or fade the colours.
I attach a photo taken from my scope for you to study. That's not actually PWM is it?
OK so I can see I have a few issues to get over: My options would seem to be:
1. Interface the existing (PWM?) drive to switch three higher power FETs so I can control the 100W LED in the same way the 10W one is currently being driven?
2. Buy some sort of off-the-shelf 100W RGB LED driver that let's me switch the colours on and off using logic level (TTL?) which I whould be able to interface from the microcontroller on the existing driver board
3. Build my own driver as speciifed in option 2
4. - over to you guys.......
Regards cooling - the existing light has an external ront mounted heatsink. I was hoping to replace this with a CPU Heatsink/fan as these seem quite capable of dissipating some high amounts of wattage
All help much appreciated
Rich