Hi All,
I have a regulated 12v regulated power supply with built in pwm. The plan is to run a 12v XHP50 or similar from this power supply. I’m looking for options to either limit maximum current, implement current overload protection, or both.
From what I have read this could be as simple as adding a zener diode. My inner cynic, however, tells me it can’t possibly be that simple.
Any suggestions would be much appreciated.
You know thermal runaway applies to batteries not power supplies right? The old icr chemistry in particular.
What is the maximum current of your power supply. You could probably put a resistor in line to reduce the current the led sees. The resistor value depends on the max current and what current you want it to see. Worst that would happen is the led gets to much current and dies. And you buy another.
No I didn’t :). As you can probably guess it’s fair to say that my understanding of electronics is rudimentary at best.
Thanks for the reply. So that you get a better idea of the setup I have a 12v 200w power supply running into a PWM that is rated up to 8 amps per channel. I’m looking to run an led up to 12w maximum off each channel. From what I understand using a resistor (12 ohm / 1 amp) would result in heat issues and be very inefficient.
Someone with more experience then me could help you more then I can. But away around using a resistor that I can think of is wiring more then one led per channel to lower the current per led. Maybe 3 xhp50s to get a little under 3 amps per led. The xhp50s are pretty tough leds. Even 2 per channel they can handle 4 amps easily that’s at 6 volts at 12 volts they should be able to handle 2 or 3 amps.
I don’t know much about resistors or values but I imagine you could wire as many in parallel until you get the wattage you wanted without using a resistor. Unless you have to have one led per channel. Or maybe run into another pwm that lowers it more. IDK about that one honestly
Thanks again. Browsing through Fast Tech I’m wondering if the following would work.
https://www.fasttech.com/products/0/10032925/7217301-22mm-2300-2500ma-1-mode-dimmable-led-driver
The output voltage of that is 5.8 to 6 volts and about 2.5A. Good enough for a single 6V XHP-50. It appears to be single mode with no overheat protection (none described) but will limit the current for you. As you’ll be running from a power supply, low voltage protection is irrelevant.