Buzzing noise with HLG driver?

Mellodrama

Mellodrama

Well-Known Member
Any of you guys hear a buzzing sort of noise when you dim your Meanwell drivers back pretty hard?

I've got a brand new HLG-320H-C1400B. This is a kit, so I assume that it's matched correctly to the six CXB3590's. The driver is capable of about 300W according to my Kill-A-Watt.

When cranked down to 120W or so there's an annoying buzzing/howling sound. Kinda like an old fluorescent ballast. I took the timer and Kill-A-Watt out of the picture. Still buzzes. Removed the pot. Buzzing goes away. But it's also quiet if you put the pot back in and crank it up past 200W or so.

It only buzzes when dimmed. And it's not exactly deafening; I can't hear the buzz at all from 10 - 15 feet away. I've never messed with one of these big drivers so maybe it's not uncommon. However, if it's a sign that something's not right I'd like to get it straightened out.
 
bassman999

bassman999

Well-Known Member
I have some no name drivers that I thought were vibrating, but its actually buzzing sound eminating from it.
Still trying to diagnose the issue.
These driver were bought used so could be well worn.
 
SquirrellyWrath

SquirrellyWrath

Member
I just build a 300w light with the same driver and I’m getting the same buzzing sound whenever I dim it to around 50% but st the top and bottom levels it’s quiet. Waiting on a reply from meanwell I’ll post back when I hear from them.
 
buyyouabeer

buyyouabeer

Well-Known Member
Yeah it is safe, happens a lot on video cards. When you dim it down it must just get to the right power level to occur; not exactly the same phenomenon but it's the circuit harmonic frequency.
 
JavaCo

JavaCo

Well-Known Member
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JavaCo

JavaCo

Well-Known Member
bassman999 said:
Hi JavaCo, what are you doing with these? Are you replacing a rheostat dimmer?
Click to expand...
The Square Wave PWM replaces the Pot for dimming. But meanwell drivers need a 10 volt pwm signal to work correctly, Powering the module with 10 volts does the trick. So what you asked about are voltage regulators. They just take a higher voltage and let you adjust it down to what is needed. The PWM module dims via duty cycle so 1 to 100% duty cycle adjusts the dimming. But with the PWM you can also adjust the frequency the driver operates on. By default the drivers run 3khz or 3000hz if you just slap a pot on one or use voltage to adjust the dimming. So with PWM you can take the operating frequency down to 100 hz. which just means it switches on a 100 times a second rather then the default 3000 times a second. By lowering the frequency it will make the driver less noisy. plants like the lower frequency for some reason, there is a post in here somewhere with science on how tomatoes where tested at different frequencies and the lower the frequency the more photosynthesis was recorded. Pretty sure it was from the University of New Mexico and was posted by stardustsailor. But yeah this is for the PWM dimming option on HLG data sheets
 
bassman999

bassman999

Well-Known Member
JavaCo said:
The Square Wave PWM replaces the Pot for dimming. But meanwell drivers need a 10 volt pwm signal to work correctly, Powering the module with 10 volts does the trick. So what you asked about are voltage regulators. They just take a higher voltage and let you adjust it down to what is needed. The PWM module dims via duty cycle so 1 to 100% duty cycle adjusts the dimming. But with the PWM you can also adjust the frequency the driver operates on. By default the drivers run 3khz or 3000hz if you just slap a pot on one or use voltage to adjust the dimming. So with PWM you can take the operating frequency down to 100 hz. which just means it switches on a 100 times a second rather then the default 3000 times a second. By lowering the frequency it will make the driver less noisy. plants like the lower frequency for some reason, there is a post in here somewhere with science on how tomatoes where tested at different frequencies and the lower the frequency the more photosynthesis was recorded. Pretty sure it was from the University of New Mexico and was posted by stardustsailor. But yeah this is for the PWM dimming option on HLG data sheets
Click to expand...
Thanks the info? Do you just power it from line AC voltage?
 
JavaCo

JavaCo

Well-Known Member
bassman999 said:
Thanks the info? Do you just power it from line AC voltage?
Click to expand...
On my set up I take a line off my 12 volt DC PSU used for fans then go into the voltage regulator with 12 volts , take a voltage meter and adjust the output of the Voltage reg and adjust it down to 10 volts then use that to power the Square Wave PWM module. The Output of the PWM goes to the Drivers Dim wires rather then a pot. But unlike a Pot you have to be sure to hook - to - and + to +. Hooking the PWM module or voltage regulator to AC voltage would create a nice little toxic cloud of smoke so I would advise against it.71Tr-2Uc3sL._SL1000_.jpg
 
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bassman999

bassman999

Well-Known Member
JavaCo said:
On my set up I take a line off my 12 volt DC PSU used for fans then go into the voltage regulator with 12 volts , take a voltage meter and adjust the output of the Voltage reg and adjust it down to 10 volts then use that to power the Square Wave PWM module. The Output of the PWM goes to the Drivers Dim wires rather then a pot. But unlike a Pot you have to be sure to hook - to - and + to +. Hooking the PWM module or voltage regulator to AC voltage would create a nice little toxic cloud of smoke so I would advise against it.View attachment 4219313
Click to expand...
I appreciate the info and diagram!
 
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