Oshpark Projects

The capacitor isn't holding a charge by any chance and plus providing a false "on" signal to the MCU?*

- Matt

* I've put not thought into this comment what-so-ever.

That was Mattaus’s handywork on the build of the OSHPark board (and design thru Eagle), comfy and rufus giving expertise…and me just being able to cheerlead them on

That is what I did with TexasPyro 20mm Nanjg…ended up flashing it to STAR V1.1 though, it caught me off guard because I thought I already flashed it…but started getting the flashies…hah

Maybe I will just offer my services for soldering and flashing drivers (for a small nominal fee)

and OUCH on the smoking of the emitter…dang, but it happens

It’s embarrassing, but a learning curve with lots of help and support from the tutors here at BLF. I’m getting better. My patience or lack of patience is my downfall.

Nope, if I disconnect power while it's on I can see it drain the cap, as it fades down to nothing which looks different than blinking off instantly when turned off via the momentary switch. I did try shorting the cap to drain it before connecting power but it still does it just the same.

Maybe I missed it, but for the 15 mm DD FET driver, has anyone tested that FET, or assembled/tried this driver yet? Do we have a good feeling this FET and driver will work ok?

Anyone have a DigiKey listing for the FET?

The fets were used by Werner but I would not call them thoroughly tested. By itself one blew but I think that was with an 18650 so he designed his board for four but that is still testing. That size driver is meant for 14500 applications where the current available is less. It should be ok with a 10440 but might need 2 stacked with an IMR 14500. This is hypothetical at this point as I have a few but haven’t tested them yet. I can pop two in the mail if you want to try them out. I got them on eBay for less than .30 ea. I was going to try one out on a blank single mode board first but that won’t happen til the week end.

Hhmm. No rush - I ordered the 15mm boards, very cheap, so if you get a chance to try it out this weekend and post, that would be great. Probably wil be a couple of weeks before I can get to them anyway. I got a UniqueFire G10 and a Romison RC-29 which are nice quality little 14500 lights which will really benefit from a programmable driver like this. The G10 has a single mode driver with a XP-G2 in it, and the RC-29 is totally stock with the next mode memory PIA thing. I got some other 14500 15mm lights as well.

I have some of the 17s but haven't built one yet. No 15s here, don't really have a use for them.

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So I tried this, didn't have any effect-

(http://edn.com/design/components-and-packaging/4364020/Reduce-acoustic-noise-from-capacitors)

So noise is not from the little cap. It's not caused by the inductor, either (still makes noise with the inductor removed completely, and the pads jumpered), though the inductor used can have an effect on the noise. So far, the quietest one is the .58uH Panasonic...

It doesn't drop the low mode as low as the .8/1.0/1.2uH parts, but you can always drop your PWM values all the way down to '1', and it's pretty damn low. Lower inductance also means it has less of an effect on the higher modes (less DC resistance).

Are there any other options for PWM frequency with the attiny13? Like, lower, where it might be outside the resonant frequency of the parts on the board?

You could try 2.4kHz, which requires changing F_CPU in the source code to 9600000 and a low fuse of 6a. Or you could leave the low fuse and F_CPU as-is but set it to Fast-PWM with a prescale of 8, which would get you around 2.2kHz, or increase the CPU speed to make it even faster (if I have all of that right).

 * define F_CPU 4800000  CPU: 4.8MHz  PWM: 9.4kHz       ####### use low fuse: 0x75  #######
 *                             /8     PWM: 1.176kHz     ####### use low fuse: 0x65  #######
 * define F_CPU 9600000  CPU: 9.6MHz  PWM: 19kHz        ####### use low fuse: 0x7a  #######
 *                             /8     PWM: 2.4kHz       ####### use low fuse: 0x6a  #######

OK, so why is STAR 1.0 silent (just now tried it for the first time (no changes other than sticking in my favorite levels, 0,2,6,18,54,130,255), using same 0x75/0xff as before), but minimo is noisy as hell? I don't understand the code well enough to translate between the different versions to pick out which difference causes the different behavior...

STAR uses Fast-PWM at 18.75 kHz and MiniMo uses Phase-Correct at 9.4 kHz (just like Luxdrv and BLF-VLD). That 9.4 kHz seems to make every setup whine, and Fast-PWM makes it silent. But I thought the FET setup didn't work with Fast-PWM? Or did your hardware changes now allow it to work?

I don't know, I just took the original STAR v1.0, plugged in my PWM levels, flashed it using 0x75/0xff, and it works.

.txt file of what I pasted into Atmel Studio: http://75.65.123.78/blf-srk/t1.txt

This is weird because I've been using luxdrv with phase-correct at 9.4 kHz for over a year and can't seem to hear a whine in PWM modes at all, on all my builds - lots. Am I just not sensitive to it? Of course at my age, I can't smell much or taste much either - I have to smother my meals in Habernero sauce so I can taste something at least, though it may be somewhat painful... Got my 1,000 lumens EDC strapped to my head and drug store #3 glasses on just to get something done on the bench... It's fun, Just you guys wait and see...

My clicky switch/luxdrv lights whine from the switch (the little contacts inside wiggle around), lightly pressing on the switch changes the pitch/volume. Obviously that's not where the noise comes from on the momentary lights though.

Great thread Rufusbduck!


About whining drivers and FETs. Its the main reason why im still on the sideline and seeing all the progress being made by knowledgeable people... I hope you guys finds the solution. I prefer my lights to not sound like there is something wrong with them..

Keep up the good work everyone!

Talking to the EE's at work, they said the magic # is 20 kHz or higher - out of the human range.

Or lower, too. Lower frequency will be less likely to make parts this size move in a way that makes audible noise. Like if you take a poly done tweeter and send it a 200hz signal, it will move but not enough to make a noise you can hear.

The fast PWM in STAR works well with the K4212... I accidentally did that when I was testing the momentary at first. Forgot to switch it...the low modes just weren't nearly as low, high modes were the same. Never tried it with the 70N02 but it may just work as well.

The inductor/etc. seems to definitely add a lot of squeal depending on the size and as Comfy has noted, the size of the capacitor. The problem is that a large inductor + large capacitor = not enough room!