Hi all. I have the 22mm boost driver for XHP70.2,XHP70.3 HI,input 3-4.2V,output 6V 5A,no pwm,constant current,4modes,12groups driver. Lots of good pics of the driver here https://shorturl.at/EUW0G
I would like to run four UV leds in a 2s2p configuration with this driver. In its current state it will not power the LEDs to more than about 200ma. I assume this is because my LED voltage is higher (about 7.45v). I will also need to make an adjustment to the current.
I would like to Pay one of you to test and see which components would need to be replaced in order to get this working correctly. I can pay cash, or flashlights. Just let me know what you want!
For changing the output voltage range, the top (or bottom) resistor of the FB voltage divider need to be changed :
Likely the top resistor is the green one and the bottom resistor is the blue one, although I can’t say for certain just from the picture, their values needs to be known (I’m not sure they can be measured accurately in circuit with a DMM) for calculating the new top (or bottom) resistor value.
For changing the current the current sense resistor next to the LED- wire need to be changed.
edit : you can probably measure them in circuit, I did it on the 22m 12V driver and the values where close to real (bottom was 47k)
Assuming it’s 47k and that your average Vf is 7.45V (?), then Rtop= 47×(7.45-1)/1= 303, 300k will do.
as for the output current, the value is partially hidden but looks like 10mR :
Rnew = R×I/Inew
For example for 4A : Rnew = 10×5/4=12.5mR, that’s not a real value, 12mR would give Rxi/12= 10×5/12=4.17A
4 Thanks