musht Posted March 30, 2018 Share Posted March 30, 2018 Sunpower as well , not sure what they are like nowadays, used to be competitive https://www.sunpower-uk.com/product-category/dimmable-drivers/ Link to comment Share on other sites More sharing options...
Gerry Posted March 31, 2018 Author Share Posted March 31, 2018 Sunpower as well , not sure what they are like nowadays, used to be competitive https://www.sunpower-uk.com/product-category/dimmable-drivers/Had a look at their site.Item is 39 GBP but unfortunately 36.44 GBP carriageCheaper, and free carriage, from mouser.co.uk and free carriage.CheersGerry Link to comment Share on other sites More sharing options...
Gerry Posted April 6, 2018 Author Share Posted April 6, 2018 That's correct, the 100% output current, when your pwm control is at full on, is fixed. You have to look at the spec of the led you want to drive, and pick the correct type of driver.My Mean Well ELG-150-36B devices arrived today.Connected them mains to input and output to my 100w LED cob.The LED came on full and there was 12.6 V DC at the DIM+ and DIM- connectors.I assumed, hoped, that I needed to input 0-10V DC at these connectors to control/ Dim the LED.CheersGerry Link to comment Share on other sites More sharing options...
timsabre Posted April 6, 2018 Share Posted April 6, 2018 Yes you do, but if nothing is connected it runs on full. I believe you can also just put a 10k potentiometer across the control pins. Link to comment Share on other sites More sharing options...
Gerry Posted April 7, 2018 Author Share Posted April 7, 2018 Yes you do, but if nothing is connected it runs on full. I believe you can also just put a 10k potentiometer across the control pins.I'm using one of these My link to provide the 0-10v DC control signal.LED cob still comes on full at switch on.I have the LED cob controlled by CH1 and a test LED controlled by CH2CH1 slider makes no difference to LED cob, always full on, CH2 slider controls test LED OK.So my desk and decoder seem to be working OK.CheersGerry Link to comment Share on other sites More sharing options...
timsabre Posted April 7, 2018 Share Posted April 7, 2018 Ok on that you need to put a load resistor where the led would go, as I described previously. Can you post a diagram or photo of how you've connected it? Below is my attempt at an ASCII diagram of how you should connect it up. Remember the DMX box is not outputting 0-10V, it's just a PWM switch turning on and off. So you need to give it the 1K resistor to switch. +-------------------------+ | | +----+-------------+ | DMX B | | | | +---+ V+ Decoder G | | +++ | +---------------+ | R +---+ | | 1K | | | +-+-+ V- | | | resistor | | LED Power | | | Power input V+ +---+ +++ | | | | | | | | +---+ DIM+ | | +-------------------------+ | | | | | +----+ +---+ DIM- | | | | | | | +---------------+ | | | | +--------------------------------------------------+ Link to comment Share on other sites More sharing options...
Gerry Posted April 7, 2018 Author Share Posted April 7, 2018 Your ASCII diagram is much clearer than my scrappy hand drawn diagram I was about to post.So, simply putting a 1K resistor across V+ and R on my decoder will solve the problem?I shall try it on Monday when I can get a 1K resistor.What does the 1K resistor do? I, mistakenly, thought that the DMX decoder put out a DC supply as that is what it looks like when I measure it with my multimeter.CheersGerry Link to comment Share on other sites More sharing options...
timsabre Posted April 7, 2018 Share Posted April 7, 2018 The DMX decoder is basically 3 transistor switches (for R, G, B) which switch that pin to ground. So when you connect an LED between V+ and (say) R, the DMX decoder can turn the LED on by switching the R pin to ground, hence putting the LED across the incoming power supply. The actual R,G,B pins themselves have no voltage on them (though you might measure something floating with a meter), you need to connect a pull up resistor or other load to V+ to see a voltage. You said you had a test LED, that would probably work as a load instead of the resistor. But you'd lose a bit of voltage through the LED, might not matter to the Meanwell driver. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted April 8, 2018 Share Posted April 8, 2018 Since that DMX driver Gerry is using just outputs PWM could one use an RC filter to create a smoother, more tungsten like, dimming profile? Link to comment Share on other sites More sharing options...
Tomo Posted April 8, 2018 Share Posted April 8, 2018 No, that absolutely does not work. The LED CC driver "dim" input requires a PWM input with a certain minimum "on" time. An RC filter would destroy the PWM. Any alterations to the dimming curve must be done before generating the PWM. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted April 8, 2018 Share Posted April 8, 2018 But the driver accepts a PWM signal, a 0-10 volt signal, or a potentiometer to control the brightness, so an RC filter ought to work. Link to comment Share on other sites More sharing options...
Gerry Posted April 9, 2018 Author Share Posted April 9, 2018 Ok on that you need to put a load resistor where the led would go, as I described previously. Can you post a diagram or photo of how you've connected it? Below is my attempt at an ASCII diagram of how you should connect it up. Remember the DMX box is not outputting 0-10V, it's just a PWM switch turning on and off. So you need to give it the 1K resistor to switch. +-------------------------+ | | +----+-------------+ | DMX B | | | | +---+ V+ Decoder G | | +++ | +---------------+ | R +---+ | | 1K | | | +-+-+ V- | | | resistor | | LED Power | | | Power input V+ +---+ +++ | | | | | | | | +---+ DIM+ | | +-------------------------+ | | | | | +----+ +---+ DIM- | | | | | | | +---------------+ | | | | +--------------------------------------------------+ Got a 1K resistor today and connected as per your diagram.With the lighting desk slider, supplying DMX, at full the LED is off, moving the slider down to 0 brings the LED on. ????CheersGerry Link to comment Share on other sites More sharing options...
timsabre Posted April 9, 2018 Share Posted April 9, 2018 Are you sure you have definitely connected DIM- to V- on the power in? It sounds like you might have connected DIM- to V+ Link to comment Share on other sites More sharing options...
Gerry Posted April 9, 2018 Author Share Posted April 9, 2018 Are you sure you have definitely connected DIM- to V- on the power in? It sounds like you might have connected DIM- to V+Just double and triple checked.All connected as per your diagram.CheersGerry Link to comment Share on other sites More sharing options...
timsabre Posted April 9, 2018 Share Posted April 9, 2018 Hmm.... thinking about it that's correct of course because the DMX decoder is switching the negative side of the LED, so the PWM signal is upside down. Try reversing DIM+ and DIM- connections? Link to comment Share on other sites More sharing options...
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