Problem with KD Super P7 Driver

[Baulz]

I built a P7 helmet light using a KD Super Output SSC P7 LED Driver Board .

It worked great at first, a fantastic light.

- Then the multi-mode stopped working, the light is stuck on high. I was able to change it a few times, but have not been able to for over a week now.

- The light now cuts out for no reason, it has a couple times on downhills. Sometimes it will come back on after a few minutes, sometimes not at all for the rest of the ride. At first I thought it was a connector/cable problem, but determined power is always getting to the circuit board last night. The board and all wires are well secured in the housing, so it is not bouncing around or shorting on anything. It cut out last night sitting still on my workbench.

The circuit board is heatsinked using directions from the thread in the dealer's corner, but heat can't really be the problem based on the testing I have done (it still cuts out when the housing is cold outside at night).

Anyone else having problems like this? Thoughts on anything else I can try?

 

[triop]

Fitted this board to a dx p7 light and had the same problem for no reason it will switch off, however it will come back on simply by pressing the on/off switch, another thing i have noticed is that it interferes with my cateye computer, it wont work when the light is on, unless i move it to the other side of the handle bars, maybe its related?

 

[[email protected]]

The driver IMHO is designed to run in a flashlight for only a few minutes at a time. Fire one up sometime and hold your finger on the stack of current sense resistors on the bottom (the are labeled something like R250 for .25 ohms). These are 1/8 watt resistors that are having something like half a watt jammed thru them ... they get really hot! If your heat sinking isn't perfect, the board will self heat to the point it will shut down. Or you could have fried the resistors. Or fried the switching mosfets. Or fried the freewheel diode. Or ... Circuits that run that hot don't last too long usually.

What voltage do you run yours on? The web site says you can run them up to 12 Volts, but at least one of the capacitors (big electrolytic on the top) is rated for 10 volts. I've run mine off a 11.1 volt Li-Po battery and had problems, If I run it off a 9.6 volt NiMh battery it seems to behave better.

Some folks on the dealers corner thread mention it runs cooler off a 7.2 volt battery ... maybe try a lower voltage.

Mark

 

[Baulz]

What voltage do you run yours on? The web site says you can run them up to 12 Volts, but at least one of the capacitors (big electrolytic on the top) is rated for 10 volts. I've run mine off a 11.1 volt Li-Po battery and had problems, If I run it off a 9.6 volt NiMh battery it seems to behave better.

Some folks on the dealers corner thread mention it runs cooler off a 7.2 volt battery ... maybe try a lower voltage.

Mark

I'm using a 7.4v Li-ion pack.

The board is now inside my light housing, the only way now to check how hot it gets is to take the entire thing apart, which will not be easy due to the amount of epoxy holding it all together.

The shutting off is just so random, I can't figure it out. It just about always happens when the housing is cool, I had it pretty hot last night and it worked fine.

 

[candle32x]

I am new to such driver boards. Anyone knows where are the electrical connectivities for the battery? Is the connected wires to my LED?

 

[rayman]

I had two of this driver boards. Were my first and my last ones of this kind. Both didn't work. Now I have the driver board from 'Der Wichtel'. Just works fine and doesn't get hot :thumbsup:.

rayman