Solarforce M8 strange noise

Hi, I just buy 2 x new Solarfoce M8 and 1 x M6…… It’s a so beautiful light……. :slight_smile:

But, I have a problem with the M8 light… When I put the 3 mode switch, and I put on the light, I hear a strange noise from the led…

noise: biiiiiiiiiizzzzzzzzzzzzzzz

When I put the 1 mode switch, all is perfect… it’s 100 % silent….

Is it normal ??


s. Sorry for my english, I speak french….

That's normal - the sound is coming from the driver due to PWM switching power on and off to regulate the current.

So is the driver of the M8 actually in the tailcap and not in the head section of the flashlight?

The noise come from the head section !!!

I just looked at Foy's review, it's in the head like almost all lights. The sound should be nothing to worry about.

Sometimes the noise is there due to improper ground. I have found that to be true with several lights. Once the grounding areas are cleaned and tightened, the noise went away. Sometimes it's necessary to "mod" the ground, to get a good ground. PWM can also do it and it may just be that.

Just a thought...

That’s what I thought, but how can 2 different tailcaps change the functionality of the driver? How can 1 tailcap be a single-mode, and the other a 3-mode? Surely a tailcap is just a switch, something which breaks the circuit, or completes it? :~

Ah, sorry, I didn't even notice that it came with two switches. There must be a microcontroller in the 3-mode tailcap that regulates current. Interesting design.

Very interesting. The switch must contain a MCU controlling PWM for the modes. The driver is regulating 100% current and the MCU in the switch is changing the PWM value to give you modes.

I’ve always thought that putting the driver at the back would be better, than you can isolate the head and LEDs from the rest of the flashlight, and run that thing till the aluminum gets red hot >) No throttling because of weak driver components.

But I guess each design has got its own pro’s and con’s.