Panasonic 26V system lighting power supply

[artyb]

Hi,
I have a BH Emotion bike with the 26V Panasonic crank drive system, not the oldest system, but before the higher voltages and bike speed sensors were introduced. The bike has a power output for a 6V headlight. I tried replacing this with an suitable LED bulb replacement, and now realise that the supply is probably PWM and exceeds 6V as the LED and supply have blown... Partly I thought I'd post this as a warning to others, but also to enquire if anyone knows any more than the information on Flecc's pages about this system? I would have hoped that a fuse would have been part of the supply? I'm considering opening the casing to investigate, but could just use battery lights instead... The motor still works.
Any insight/advice welcome. Has anyone investigated/repaired this power outlet?
Thanks and Best Wishes,
A

 

[flecc]

I did publicise the potential problem of trying an LED a long time ago. The lighting supply is PWM to simulate the 6 volts, the bulb filament slow reaction being the smoothing of the supply. There is no fuse for this inside the unit and the wiring plugs straight into the encapsulated circuit board, meaning there is no component access for repairs.

Frankly I think it much better to use the bike LED battery lights that are available on the market now, far more effective for seeing and being seen.
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[artyb]

Hi Flecc,

Thank you for the reply. I waited a couple of days to see if there would be any other responses. Shame I didn't spot your earlier comment, or check the output before trying. I might see if I can repair the unit-I know skilled electrical engineers (I'll report back if I get anywhere with this, it won't be for several weeks at least), or just use battery powered lights as you say. Do you or does anyone else have any high resolution images of the PCB from that era of drive unit? I wondered if I could spot a likely failed switching component?

Best Wishes,
Arthur

 

[flecc]

I don't have a high resolution image Arthur. Unfortunately the whole board is encapsulated and sealed into the r/h crankcase side with the encapsulating material. I've seen a few failed ones with differing faults but never any visual evidence of a failed component. Of course even if there was, the lack of access due to the encapsulation limits what could be done.

With these and their chargers Panasonic obviously designed for repair by replacement only and have never made available any technical information that might assist repairs.
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