Hey, I want to drive an LCD panel. I think I have everything I need except that I bought the wrong ICs to generate its power.
The LCD requires Min 5.60 - Max 5.90v (+ and -). I bought a MAX660; not correctly reading that it doubles the voltage. Furthermore I have a few LM317 and LM337 (Not knowing you need negative voltage to regulate negative voltage).
Sigh.. So after some experimentation I've found out the following:
Driving the LM317
without resistors gives me a voltage of 5.77 at 6.25 input voltage.
Driving the MAX660 with the output voltage of the LM317 with 3 (instead of 4) 200nf capacitors at C1+-, C2+-, V- GND gives me -5.725v.
I guess using both ICs this way is out of spec, but in my naive understanding I now have +- voltage that fits the displays spec.
Can I use this setup temporarily to already tinker with the display until I actually get a proper solution, or should I not even try - as it might break the display, or might give me some other issues I need to figure out?
New ICs will take a while to arrive and I'm a bit inpatient, so a temporary solution would be fine for me. Next time I'll be more careful for sure.
Thanks!