hotwire spikes and protected li ion

i'm building 50w mag using mr16, and protected li ion 4x 32650 (d)

first the bulb wouldn't even light up, apparently turn on surge would trip protection, i installed ntp, and it turns on nice and soft now, however, as i shut it off, another surge trips protection, and it wont turn on again,
does anyone know how to deal with off spike??? besides getting aw soft start.

More details needed. How do you know it's a spike? Did you measure one, or see a flash from the bulb while turning off? Will the light turn on again after some period of time?

I don't know much about electronics, but I don't believe a ntp is capable of storage, and discharge like a cap. And even if it could, wouldn't there be no ability for current to flow as the switch has now broken the circuit?

The only thing I can dream up at the moment is the possibility of arcing in the switch while it is being shut off, maybe tripping the protection. But, that didn't happen before the ntp, so... :shrug:

EDIT: BTW, 4 X Li-ion for a 12V bulb? Sure you didn't just blow the bulb?... lol. Also, I take it these are KD/DX 32650's? If so, they've never been known for their current handling ability.

fivemega said:

BTW, if your bulb life is 5000~6000 hours, it needs 5 IMR in series to shine nicely as hotwire.

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We can ignore my 4 X Li-ion comment then.

thanks for help.
i solved the problem, i have no clue what it was but i decided not to use those cells in hotwire i,m building, i moved my 3xp7 mod to a different body (3d +88mm extention), and i use them there, so now they work without a hick up, the draw is less than 3amp there, protection doesn't cause problems there.

i used those cells in my 50w build using aw soft start, never had any problem with protection tripping, that is why it made me think off spike tripped it, cuz i did install inrush current limiter, but it only softens the spike during turning on.

but anyway, i should be getting my 26650 imr cells soon, and i'll use them in my the host that has aw soft start, and 2,5 throwmaster with 100w bulb.

now i have empty 4d dual bored mag body, what should i do with it???? i,m thinking sst90

that is a possibility, thanks.

alpg88 said:

i did install inrush current limiter, but it only softens the spike during turning on.

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Just for future information, there is no spike during turn off.

Have fun with whatever you build in that mag. FM's suggestion is pretty awesome.