Mean Well LDD1500LW dimming circuit

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Hoop's picture
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Joined: 12/20/2012 - 05:33
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Location: Spokane, WA
Mean Well LDD1500LW dimming circuit

I’ve been tasked to do an LED light install for a machine owned by a local company.

The dimming circuits I’ve made don’t work quite as well as I’d hoped. The dimming only occurs over about the first 1/4 turn of the pot before hitting max output. Strangely, my DMM shows 7V when the pot is open, even though it is being fed from a 3.3v source…

As per the datasheet, the dimmer input works from 0.3-2.5 volts. I used a 3.3V dc/dc converter to feed a voltage divider made from a log taper 1k ohm pot and a 150 ohm resistor. A 300 ohm resistor should be slightly better in hindsight, and I did try two 150’s in series with marginal improvement.

Any suggestions?

For future reference: there are 2.5v dc/dc converters. It might be worth trying one of those with a pot rather than making a voltage divider with a higher voltage source like I did.

Edited by: Hoop on 07/03/2016 - 05:53