I am interested in hooking up an LED light to the rest of my KNX system. It’s a fairly small light, driven by a constant current power supply, rated to provide 350mA between 0.5 and 10V:
I am quite familiar with the 12V/24V LED systems but I am struggling to find the right module to drive what I have.
Any tips how I can achieve dimming with the above?
Thank you!
I guess there is nothing to dimm here. Your photo says it all. You have a constant current supply with 350mA that can drive up to 3W.
I would be happy to switch the power supply as well, should have clarified.
But I struggle to find LED knx dimmers that are not constant voltage…
I have seen one that would work if I changed the power supply to the one that takes a control voltage but that seems like more of a retrofit solution if one is stuck with specific type of PSU
Constant current, you mean? If it were constant current it would not be a dimmer …
This sort of thing, perhaps
https://www.ivoryegg.co.uk/shop/products/zennio-lumento-c4-lumento-c4-4-channel-constant-current-pwm-dimmer-for-dc-led-loads
PWM means it turns the current on and off very quickly, so its like very short bursts of constant current, with gaps inbetween for “dimming”.
Then there are a lot of options. You need a dimmable LED driver. You can get them in many variations of maximum power outlet and either constant voltage or constant current. It depends on your LED application what to take best.
Most LED stripes need a constant voltage, because the have a build in current regulator. A dimmable LED driver with constant voltage gives them a constant voltage with PWM modulated.
Other LEDs need a constant current. If you have on that is dimmable, it basically does the same. Give constant current with PWM modulated.
That is because you dimm the primary side, which is alternating current (AC) and they work with phase controlled modulation (in German Phasenanschnittsteuerung).
A dimmable driver for LEDs has to translate the phase controlled modulation on the primary side (input) into a PWM modulation on the secondary side (output).
Don’t know what you mean by that. Or you mean the phase controlled modulation translation, I described? That is the most common way mainly because of there are no other simple methods of reducing the power on an AC signal.
You can, on the other hand, take other controllers like DMX or DALI.
Thank you for the tip!
