Need Help With This Driver

[vog37]

Hey guys
Got this driver hlg240-36v 6.7a
I have 2*cxb3590 not sure how to wire them and i dont want to burn everything any help will be great thankss

 

[scubascrog]

is it the 240h-c1400a? what c number is it?

 

[vog37]

No its 6.7amps its model with dimmer

 

[vog37]

Hlg 240-15a

 

[scubascrog]

Vout Max: 15 V

Will not power one 36v cob. if i am not mistaken but i am not an electrician

 

[scubascrog]

this chart says you need the -36 to run 4 of those using 50W each, given the amps arent exceeding the driver max

 

[heisen]

Hey guys
Got this driver hlg240-36v 6.7a
I have 2*cxb3590 not sure how to wire them and i dont want to burn everything any help will be great thankss

whats the model number on the driver.6.7a would be like 6700 mA so take a pic of the driver or give us the model number on it.Your missing some info

 

[sixstring]

You will need more than 2 cobs to use that driver.max amps per cob is like 2.8 I think and that's really pushing it unless you have a huge fan cooled heatsink

 

[sixstring]

4 x 36v cobs would be perfect for this driver with 140 or 150mm heatsinks

 

[sixstring]

whats the model number on the driver.6.7a would be like 6700 mA so take a pic of the driver or give us the model number on it.Your missing some info

He has a CV or constant voltage driver,used for parallel wiring setups.

 

[vog37]

Its for 2 cxb's for now later ill add 2 more can you confirm its ok for 2 using the dimmer,and if someone can add a simple draft how to wire its will be great;)

 

[vog37]

 

[sixstring]

My advice is do not use that driver for only 2 x 36v cobs.and because you are not really understanding how this voltage works I don't feel comfortable explaining how to wire this type of setup.what are your plans for heatsinks?

 

[vog37]

Im going with the 140mm attaching computer fan to it ,i have 2 full kits ordered from alibaba with drivers the lpc i think the hlg driver is for later...if you think this driver not match 2 cob's ill wait till next order..what about 3 cob's?

 

[Toaster79]

When you wire your cobs, turn the voltage output all the way down then turn it on. Now start slowly turning the voltage trimmer up and measure the current on the output until you get the desired current. Your cobs should fire up at about 30V maybe even lower but don't rely on voltage as the forward voltage of the cob is gonna change with the temperature which means that your cob is gonna start pulling more current as it warms up at the same voltage. That's why constant current drivers are normally used for such applications.

Like I said wire your cobs in parallel, adjust the voltage and measure the current. Let them them run for an hour and see how much current changes at given voltage and readjust.

 

[Toaster79]

That driver will run 1 or 10 cobs. Max output is 6.7A but that doesn't mean it's gonna deliver full power if the cob doesn't demand it. That's why you need to adjust the voltage when your cob is at working temp not cold.

 

[vog37]

Thanks for the info man thats help alot its much more clear now;)

 

[Toaster79]

Anytime

 

[vog37]

What actually limit the cob from pulling more and more current until warm enough to die?

 

[Toaster79]

What actually limit the cob from pulling more and more current until warm enough to die?

With a constant current driver the cob will get limited current and the driver will adjust the output voltage to match and keep the current the same. With a constant voltage driver you are setting the output voltage to match the desired current.

Now let's say your cob is pulling 2.8A at 36V. When it warms up the voltage of the cob drops to say 34.8V to maintain those 2.8A. If your driver is still delivering 36V the cob will now run at 5A at that voltage instead of at 2.8A if the driver is capable of delivering those amps other wise the cob will see the max amps of what the driver can deliver. In your case with a 36V driver and 6.7A max current it can happen that the cob is gonna warm up so much it's gonna want all those amps if not cooled properly.

Keep in mind those numbers are given at 25°C junction temperature (36V 2.8A). At 50°C your cob is gonna run at say 34.8V at 2.8A and at 85°C 33V at 2.8A. Now don't take those numbers for granted i used those for illustrative purpose. But we can go and have a look at a datasheet for a certain cob and do a bit of a math to get those exact numbers.