Hi
Please help me understand
I am confused
I need to ajust the output of a led driver
It has a adjustment pot
I hook my multimeter to the positive/negative outputs
What do I set my multimeter on???
The leds are 36 volts
If I ajust ( lower) the voltage will the leds still work???
How do I ajust the wattage???
I want to lower it.
If I lower the voltage will wattage go down??
Please help me understand…
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P=I*V (for DC voltage)
where P = power in Watts, I=current, and V=voltage.
If you reduce the voltage while the current remains that same, the wattage will decrease. Likewise, if the current is reduced with the voltage being the same, the wattage will decrease.
With the voltmeter connected as you’ve noted, across the positive and negative output, you will be reading voltage.
However, this may be confusing depending on the type of LED driver that you have. Most commercial LED drivers are current sources. This means the driver will adjust the voltage depending on the current being output. If the current is too high based on what you’ve set it to, the driver will reduce the voltage. This, in turn, will decrease the current. If the current is lower than the set-point, the driver will attempt to increase the voltage up to some maximum value. This will increase the current output.
In order to measure the action voltage of a typical LED driver (current source) with a voltmeter, you’d connect the LEDs to the output of the source while also reading the voltage across that output. The meter is in “parallel” with the driver. The driver will adjust the output voltage to meet the current set-point. If there is nothing connected to a current sourcing driver, it will likely just go to the full voltage and stay there. This is the open circuit voltage. Current = zero in this case.
If you want to read the current, you would first make certain your meter is set-up for current (different set of inputs). The meter will now act like a piece of wire. So, you would connect one output of the driver to one end of the meter. The other end of the meter would go to the corresponding input into the LEDs. The, other, unconnected LED terminal would go to the unconnected output terminal on the driver. The meter is in “series” between one output of the driver and one input of the LEDs.
Suggestion is to reduce the adjustment to the minimum and then, with a meter connected, slowly increase the adjustment value until you see what you’d expect (either/and current/voltage).
Not all drivers are current mode, though.
For your driver, does it specify if it’s for LEDs and, if so, does it say what the output voltage / max current is?
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If your Led’s are 36V, they will not light up if you lower the voltage.
I use constant current drivers for my Led’s, if I wanna change the current I have to change the driver itself.
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what type of driver specifically do you have? usually you just dial the knob or use a screwdriver for A type drivers
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