Led buzzing/humming

Reignman · 2019-01-27T03:21:54.000Z

Anybody ever have this happen? Was testing an led prior to installing and heat sinking with a quick flash or two and I immediately noticed some buzzing… is it from heat? I am concerned it could be an issue with the circuit but the noise was definitely seeming to be coming from the led

Reignman · 2019-01-29T04:31:30.000Z

anybody have any ideas on this one?

Mike_C · 2019-01-29T10:00:49.000Z

PWM that’s making the noise maybe? Audible PWM as a known annoyance with some drivers.

Reignman · 2019-01-29T10:13:52.000Z

Mike C:

PWM that’s making the noise maybe? Audible PWM as a known annoyance with some drivers.

I’m assuming that’s pulse with modulation?
Just wanna make sure I’m not going to fry the LED but I can’t see that happening at 32v when it’s a 36v led.

Mike_C · 2019-01-29T10:36:27.000Z

Reignman:

I’m assuming that’s pulse with modulation?

Yes. Do you have a power supply unit where you can power the LED directly without the driver? Starting with low voltage and slowly increasing so you don’t fry it. If it’s PWM that’s making the noise you should hear nothing with powering directly from the power supply.

I’ve also heard that a trick to verify PWM noise is to put something black in front of the LED, preferable matte black, while it’s been driven from the driver. If the noise gets louder then it is PWM that is the cause. I can’t vouch for this trick myself though, I don’t use drivers that utilize PWM.

Reignman · 2019-01-29T11:56:22.000Z

Mike C:

Reignman:

I’m assuming that’s pulse with modulation?

Yes. Do you have a power supply unit where you can power the LED directly without the driver? Starting with low voltage and slowly increasing so you don’t fry it. If it’s PWM that’s making the noise you should hear nothing with powering directly from the power supply.

I’ve also heard that a trick to verify PWM noise is to put something black in front of the LED, preferable matte black, while it’s been driven from the driver. If the noise gets louder then it is PWM that is the cause. I can’t vouch for this trick myself though, I don’t use drivers that utilize PWM.

Don’t have an alternate driver sadly. Is pwm going to hurt it? Don’t mind the noise if it’s safe to run that way. I don’t see any flickering or change in brightness with the naked eye.

Mike_C · 2019-01-29T15:50:10.000Z

PWM in itself won’t hurt it, most drivers here use it in one way or the other. It’s the current draw during the on pulses that could eventually hurt it if it’s really high.