Dimming the 320h-24a. VO or LO?

nfhiggs

Well-Known Member
Its io not Lo and put your volts up, dim with amps aka Io
If you want the driver running in CC mode, then sure, do it that way. BUT you can dim with either one. The issue with maxing the volts and dimming the current is if you have parallel loads, you may encounter current hogging while running in CC mode. IMO, its better to have some current overhead and keep your voltage stable. I max the current and adjust the voltage to get my desired current in the loads.
 

butterbudface

Well-Known Member
If you want the driver running in CC mode, then sure, do it that way. BUT you can dim with either one. The issue with maxing the volts and dimming the current is if you have parallel loads, you may encounter current hogging while running in CC mode. IMO, its better to have some current overhead and keep your voltage stable. I max the current and adjust the voltage to get my desired current in the loads.
doesnt make sense to dim with Vo,

Adjust voltage to the chips forward voltage then adjust amps, i only run constant voltage drivers with Chips in parallel.
 

butterbudface

Well-Known Member
Because if you dim the cob with volts, i mean you turn it down too much, some of the leds in the cob array does not come on and it looks something like this.

cob.PNG
 

nfhiggs

Well-Known Member
Because if you dim the cob with volts, i mean you turn it down too much, some of the leds in the cob array does not come on and it looks something like this.

View attachment 4139694
Absolute nonsense. As 1212ham pointed out - that pic was reducing the current in a cheap $2 COB to ridiculously low levels. Try measuring the voltage across your COB when you dim it with the current control. You'll notice the voltage decreasing. The fact is that you should not use CC control with parallel loads - it leaves you with no current overhead and *can* result in current hogging.
 

butterbudface

Well-Known Member
That's from dimming a cheap cob to a ridiculously low level, not from CV vs CC.
i use vero 29's , cxm 22's and new samsung strips, not cheap at all.

Uh.. so what exactly should I turn down? Because I only turned down the VO to 100watts.. should I also do IO as well then?
put your volts up and dim with amps?

Absolute nonsense. As 1212ham pointed out - that pic was reducing the current in a cheap $2 COB to ridiculously low levels. Try measuring the voltage across your COB when you dim it with the current control. You'll notice the voltage decreasing. The fact is that you should not use CC control with parallel loads - it leaves you with no current overhead and *can* result in current hogging.
I dont use cheap cobs, that was a pic from the interwebs. please explain how you would go about dimming your cobs?
 

Rocket Soul

Well-Known Member
Uh.. so what exactly should I turn down? Because I only turned down the VO to 100watts.. should I also do IO as well then?
Id suggest checking out ledgardeners youtube series about meanwell drivers.

Io dimming: just straight dimming of the current and proportional dimming of light.

Vo dimming: normally not used for dimming, its more used for setting up the driver so that you dont damage your leds in a paralell setup if one of your leds fails: you set it so that Voltage matches the desired current level. If one of your led strings fail the current that was passed thru that string would go to the other strings normally, possibly overloading the circuit. If you set Vo correctly this cant happen: the driver wont be able to feed more current as it is limited by voltage setting and cant feed more current than what the led can take at that voltage.
 

butterbudface

Well-Known Member
Id suggest checking out ledgardeners youtube series about meanwell drivers.

Io dimming: just straight dimming of the current and proportional dimming of light.

Vo dimming: normally not used for dimming, its more used for setting up the driver so that you dont damage your leds in a paralell setup if one of your leds fails: you set it so that Voltage matches the desired current level. If one of your led strings fail the current that was passed thru that string would go to the other strings normally, possibly overloading the circuit. If you set Vo correctly this cant happen: the driver wont be able to feed more current as it is limited by voltage setting and cant feed more current than what the led can take at that voltage.
Couldn't of said it better
 

nfhiggs

Well-Known Member
Uh.. so what exactly should I turn down? Because I only turned down the VO to 100watts.. should I also do IO as well then?
Again - you CAN use either one. With parallel loads its is BEST to have some current overhead to reduce the possibility of current hogging. That means leaving the current adjustment (IO) at maximum and adjusting the voltage (VO) to your desired wattage level.
i use vero 29's , cxm 22's and new samsung strips, not cheap at all.
Irrelevant - the pic is not a Vero 29.

If one of your led strings fail the current that was passed thru that string would go to the other strings normally, possibly overloading the circuit.
If you are running your devices that close to their maximum then you're doing it wrong. Do you guys understand how current hogging occurs?
.
 

butterbudface

Well-Known Member
Again - you CAN use either one. With parallel loads its is BEST to have some current overhead to reduce the possibility of current hogging. That means leaving the current adjustment (IO) at maximum and adjusting the voltage (VO) to your desired wattage level.

Irrelevant - the pic is not a Vero 29.


If you are running your devices that close to their maximum then you're doing it wrong. Do you guys understand how current hogging occurs?
.
I know exactly what current hogging is. Not going to argue with you over shit like this.

@ OP play around with both and you will quickly see whats up.
 

Prawn Connery

Well-Known Member
Vo dimming: normally not used for dimming, its more used for setting up the driver so that you dont damage your leds in a paralell setup if one of your leds fails: you set it so that Voltage matches the desired current level. If one of your led strings fail the current that was passed thru that string would go to the other strings normally, possibly overloading the circuit. If you set Vo correctly this cant happen: the driver wont be able to feed more current as it is limited by voltage setting and cant feed more current than what the led can take at that voltage.
All the boards I've built so far (5) run parallel strips and that's what I do - max out the amps and dim the volts to protect against thermal runaway.
 
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