Saturday, November 29, 2008

Timing light

Seeing as to how expensive, and impossible to get timing lights were in Singapore. I decided to make one out of little parts I had lying around. They are rather simple devices actually, a High-voltage power source for the Xenon flash tube, the flash tube itself, a little storage capacitor for the HV, and something to trigger the flash (the 3rd wire that goes around the flash tube, HV ionises the gas inside and causes the tube to fire).

The trigger itself can be the HV straight out from the Ignition coil, not the best solution, but it'll work. I wired a small black wire (you can see in the picture) to the trigger connection on the flash tube. The entire assembly was hot glued to a little plastic tray semiconductors are held in.

HV was produced using a small CCFL power supply. 12VDC in will result in almost 300VAC out on one leg. I used both phases on the board (board can power 2 CCFLs) to generate about 700VAC, used a couple of high-voltage rectifiers to convert that to DC the flash tube required, a smallish HV capacitor to store the charge.

Flash tube was from a disposable Kodax camera, had a couple of these some time ago when I was messing around with coil guns, I had gutted them for the storage capacitors to build a bank, I got these free from a photo developing store nearby, had to wait quite abit before they had some though.

Hooked up the timing light, and timed the 009 to 30deg BTDC at 4000RPM. It fell to 12deg BTDC at idle (about 1K RPM, we still had the high idle even-with-bypass-screw-totally-in syndrome). Engine was alot more responsive and powerful now with the timing 'right'. I'd recommend everyone who is using a 009 to time it using a timing light at max advance. There's no knowing where it'd fall to at idle. This seemingly high idle RPM advance makes me think either the distributor is worn, or someone messed with it before.

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