If this has been asked previously, I have not yet found it. I've never posted here, so please accept my apologies in advance if this post isn't appropriately written.

I'm building a test rig for lighting control systems for training and demonstration. Ultimately I'll be using 16 manufactured dimming control modules, an Arduino Mega for it's analog inputs, and a TLC5940 to drive 16 channels for visual representations of each dimming module's level. The dimming level for each module will be picked up through voltage dividers on each module.

My question isn't about the TLC5940, or the Mega - I'm stuck on how to simulate an LED driver's 0-10v input.

Each dimming control module is able to sink somewhere around 5-10mA of current on the 0-10v wires. They do not source any voltage, and they're designed to manage a single LED driver each. I'd like to use a single power supply (12vdc with a voltage regulator most likely) to feed all 16 10vdc feeds, with each of them current limited to about 2mA each.

What is the dead-simplest way to provide the 10v with the current limiting?

  • 1
    \$\begingroup\$ you cannot hold the power supply output at 10V and 2mA if the load varies ..... you can either have a constant voltage power supply or a constant current power supply, but you cannot have constant both, unless the load is a constant 5k ohms ...... that said, you can have a constant voltage supply with current limiting ....... the output voltage would begin to drop to keep the current at or below the set limit ..... similarly for a constant current supply \$\endgroup\$ – jsotola Feb 13 at 5:58
  • \$\begingroup\$ Which lighting control? The ones I have laid my hands on had 10 V pull-up for the very purpose. \$\endgroup\$ – winny Feb 13 at 8:01
  • \$\begingroup\$ I'm targeting a few control systems, all of which use 0-10v dim-to-dark drivers. The rig will allow me to change out the dimming controllers to suit the occasion, and allow for a half-and-half setup from two different manufacturers for comparisons. \$\endgroup\$ – Kalavek Feb 14 at 3:25
  • \$\begingroup\$ The current-limited dimming lines of a fixture driver puts out 10v - if you begin applying an impedance, the voltage is expected to drop. As the voltage drops, the fixture's driver reduces the intensity of the LEDs. 0-10v fixtures will be at full brightness if the 0-10v leads are open, and will drop to their dimmest level when the leads are shorted. If you're only applying enough impedance to reduce the voltage to 5v, the fixture will be at roughly half-brightness. \$\endgroup\$ – Kalavek Feb 14 at 3:31

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