Max Amperage problem with MW drivers

PilouPilou

PilouPilou

Well-Known Member
Hi all! Firstly let me wish you all a happy new year and all the best for you and your family.

Well.. here is my problem! After a test with my multimeter I noticed that the 2 MW drivers I use (hlg 240-c1750b) have a max Amperage of 1580/1600mA instead of 1750mA: they are connected to 4 CXB3590 36V each and they come from an official distributor, not from China. It is the new version with the new design/stickers.

Here are the specs of the potentiometer and resistor I use, maybe it is the problem!
Resistor: 10kΩ - power 0.4W- tolerance +/-0.1%
Potentiometer: 100kΩ - power 500mW - tolerance +/-20%

Thank you in advance for you replies guys!
 
W

Wonder.Hippy

Active Member
PilouPilou said:
Hi all! Firstly let me wish you all a happy new year and all the best for you and your family.

Well.. here is my problem! After a test with my multimeter I noticed that the 2 MW drivers I use (hlg 240-c1750b) have a max Amperage of 1580/1600mA instead of 1750mA: they are connected to 4 CXB3590 36V each and they come from an official distributor, not from China. It is the new version with the new design/stickers.

Here are the specs of the potentiometer and resistor I use, maybe it is the problem!
Resistor: 10kΩ - power 0.4W- tolerance +/-0.1%
Potentiometer: 100kΩ - power 500mW - tolerance +/-20%

Thank you in advance for you replies guys!
Click to expand...
I believe the voltage is to low on the driver (143) to squeeze the 1750ma across the 4 cobs(36x4=144).
 
pirg420

pirg420

Well-Known Member
PilouPilou said:
thx for your reply - it seems it is not the problem: the COB LED CC Driver selection tool of ledgardener announce 139.6V for 4 CXB at 1750mA
http://ledgardener.com/cob-led-driver-selection-tool/
Click to expand...
No, @Wonder.Hippy is right, you wont get a full 1750 ma out of that driver with those chips, it will be slightly less.

if you tried to use citizen 1216s the effect would be even worse (less total amperage/wattage) since they have a slightly higher forward voltage.
 
PilouPilou

PilouPilou

Well-Known Member
pirg420 said:
No, @Wonder.Hippy is right, you wont get a full 1750 ma out of that driver with those chips, it will be slightly less.

if you tried to use citizen 1216s the effect would be even worse (less total amperage/wattage) since they have a slightly higher forward voltage.
Click to expand...
Ok thank you! So the numbers of the ledgardener tool are not good... :/
 
nfhiggs

nfhiggs

Well-Known Member
PilouPilou said:
Hi all! Firstly let me wish you all a happy new year and all the best for you and your family.

Well.. here is my problem! After a test with my multimeter I noticed that the 2 MW drivers I use (hlg 240-c1750b) have a max Amperage of 1580/1600mA instead of 1750mA: they are connected to 4 CXB3590 36V each and they come from an official distributor, not from China. It is the new version with the new design/stickers.

Here are the specs of the potentiometer and resistor I use, maybe it is the problem!
Resistor: 10kΩ - power 0.4W- tolerance +/-0.1%
Potentiometer: 100kΩ - power 500mW - tolerance +/-20%

Thank you in advance for you replies guys!
Click to expand...
Check your potentiometer's actual value with a meter. At 20% tolerance it may not be hitting 100K even with the resistor.
 
Randomblame

Randomblame

Well-Known Member
PilouPilou said:
Hi all! Firstly let me wish you all a happy new year and all the best for you and your family.

Well.. here is my problem! After a test with my multimeter I noticed that the 2 MW drivers I use (hlg 240-c1750b) have a max Amperage of 1580/1600mA instead of 1750mA: they are connected to 4 CXB3590 36V each and they come from an official distributor, not from China. It is the new version with the new design/stickers.

Here are the specs of the potentiometer and resistor I use, maybe it is the problem!
Resistor: 10kΩ - power 0.4W- tolerance +/-0.1%
Potentiometer: 100kΩ - power 500mW - tolerance +/-20%

Thank you in advance for you replies guys!
Click to expand...
This is not unusual if you use simple pots with 100k!
You need to check the resistance of the 100k potentiometers. They are usually wide spreaded and can be between 85 and 115k. A poti with only 90k allows only 90% of the drivers maximum and this is IMO the most possible reason for your readings.
Also there is no need to use a 10k resistor the driver is anyway limited at 8-10%.
 
Randomblame

Randomblame

Well-Known Member
The best way to use the full potential of the B meanwell driver is to use a 108k poti if you find one in a batch of 5, 110k works also. The cheapest B100k ones are more than enough as long as they are linear and you get a bunch of 5 for only 2 or 3$ on e3ay.


If you look at the datasheet, dimming section, you will see the most drivers are able to deliver up to 108%, with a siutable potentiometer you can use this potential without using an additional switch on the dimmer circuit..

Screenshot_20180101-194408.png

Here are 10 for 1,85$

https://www.ebay.com/itm/10PCS-B100K-OHM-Linear-Taper-Rotary-Potentiometer-WH148-15MM-Shaft-3-Pins/191976481748?epid=1645981930&hash=item2cb2b0a3d4:g:KeAAAOSwzaJX4iVZ
 
PilouPilou

PilouPilou

Well-Known Member
Randomblame said:
The best way to use the full potential of the B meanwell driver is to use a 108k poti if you find one in a batch of 5, 110k works also. The cheapest B100k ones are more than enough as long as they are linear and you get a bunch of 5 for only 2 or 3$ on e3ay.


If you look at the datasheet, dimming section, you will see the most drivers are able to deliver up to 108%, with a siutable potentiometer you can use this potential without using an additional switch on the dimmer circuit..

View attachment 4066411

Here are 10 for 1,85$

https://www.ebay.com/itm/10PCS-B100K-OHM-Linear-Taper-Rotary-Potentiometer-WH148-15MM-Shaft-3-Pins/191976481748?epid=1645981930&hash=item2cb2b0a3d4:g:KeAAAOSwzaJX4iVZ
Click to expand...
Thank you for the infos! The potentiometer I use is already 100K. Is there a difference with the one of your link?
 
ledgardener

ledgardener

Well-Known Member
I think it has to be the pot because even if you were somehow able to run them at a real cool temp like 25°C, their voltage would only be 35.5 at most, according to the Cree calculator. 4 of them would be 142V which is in range if that driver. Obviously more heat will reduce this voltage even further.

Best way to check, as others suggested, is to remove the pot.
 
V

VegasWinner

Well-Known Member
All potentiometers are NOT created equal. Measure your potentiometers resistance for verification. Does it read 100k ohms? if not replace the potentiometer. You can alos use an on/off switch to get maximum output of the ndriver, but the difference between what you are reading and the max is small in the first place. replace the potentiometer. simple solution.
 
You must log in or register to reply here.
Top