Parallel 1-10 V dimming of multiple LED drivers

Question

Can I dimm multiple ie., 6 of them HLG-320H-36AB Mean Well / datasheet (NB: no impedance data related to the dimming connexions), LED drivers with the 1-10 V (not PWM) method and only one potentiometer directly?

Should all the dimm cables be plugged in parallel?

Is there a limit to the number of drivers being plugged?

Answer 1

In case you are working with MeanWell LED drivers (like their HLG/XLG/ELG family) or any other driver that provides a constant current at the DIM input, you just need to select a potentiometer with suitable resistance.

Assuming the driver sources a constant current of 100uA (like MeanWell drivers do), 100kOhm are required to produce a dimming voltage of 10V: $$R=\frac{U}{I}=\frac{10V}{100\mu A}=100 k\Omega$$ If there is more than one driver, the currents of the individual drivers add up and a smaller resistance is required to get 10V respectively: $$R=\frac{10V}{200\mu A}=50 k\Omega$$

In general, to control n drivers with one potentiometer you need to choose one with a resistance of $$R=\frac{U}{I}=\frac{10V}{n \cdot 100\mu A}=\frac{100}{n} k\Omega$$

The drivers' DIM inputs will be connected in parallel (all DIM+ go to one pot terminal, all DIM- to the other). I've not found any information about how many meanwell drivers can be controlled with one potentiometer, but in principle there should be no limit. In practice, the potentiometer will have a maximum allowed power/current consumption you should not exceed.

Answer 2

There's no way to tell for sure what you have inside your TBD LED drivers but a prudent design might have just a high resistance to 0V to disable the output with no connection. Long wires can pickup noise and a filter cap is recommended for line noise pickup such as 0.1 uF ceramic or more for intentional RC=T [s] delay. Then using the recommended pot value such as 10k can be used with twisted-pair ethernet wire for multiple inputs. STP wire would be even better grounded only at one source.

For a better solution, you must define every part and layout.

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