Fet driver flicker

Flashlight Modding and DIY Parts
1

Good evening. I have been working on a zy t-08. I have stripped the stock board to use as contact plate for 26mm fet driver flashed with guppdrv. xml u3. 18ga wiring. Braid on springs + heat sink for led.

When I use any mode other than 100% the led flickers like a florecent light that has gone bad. The light output appears to be at the right level. There is also a whine noise from the light. Noise also goes away at 100%.

I have by-passed tail cap - same.
Checked solder connections
Pill is making good contact with body
Using LG HE4 batteries
Getting 4.3A at the tail cap at 100%
Getting .95A at the tail cap at 25%
Using quality amp clamp to test

I have also not soldered #2 star to lock mode selection.

Wire connections
B+ on contact plate to center of bottom side of driver

  • Led on contact plate to outside ring on bottom side of driver

Any help would be appreciated

Thank you.

2

Welcome to BLF! :slight_smile: as for the flicker, do you have another driver to try? maybe its a bad FET chip.

3

I am thinking it’s the driver due to problem being in lower modes. I do not have another fet driver to test. Just wondering if there is something else I could be missing.

4

Could this be the PWM-flicker, one can see by putting the flashlight in parallel with the eyes direction and then synchronously panning around? That could be simply a too low PWM frequency and you are very sensitive to the “flicker”, as i am. If this flicker is unbearable you should dig for a constant current driver, that technology hasn’t any flicker at all.

5

In addition to what UliBär said about PWM, check to make sure you’re getting a good ground connection to the contact plate