Bmw E39 M5. Coil Driver

Ask for and share advice on using the PicoScope kit to fix vehicles here.
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STC
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Re: Bmw E39 M5. Coil Driver

Post by STC » Mon Sep 12, 2016 9:25 am

After a lot of messing about with alternative devices, we could never find a datasheet for the original, I finally found the same original part in China. They arrived and looked very dodgy with solder on them so I'm assuming they were used.

Upshot is that its fixed now.

victor2k
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Re: Bmw E39 M5. Coil Driver

Post by victor2k » Mon Sep 12, 2016 12:20 pm

Hello,
according to datasheet your IGBT can drive more than 20A Ice so the measured component must be faulty...why the emitter is at 14 volts and collector at gnd in your attached image?
Regards
Last edited by victor2k on Mon Sep 12, 2016 5:26 pm, edited 1 time in total.

andrewbishop66
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Re: Bmw E39 M5. Coil Driver

Post by andrewbishop66 » Mon Sep 12, 2016 12:56 pm

i would normally scope the the base or gate depending on type etc and compare to the other drivers also use a device tester on the removed one dont mind posting my tester to you to use if you like not an expensive item
if you still have drive to the base/gate supply and path though the coil to ground it would be worth testing off the board i would also find an alternative component easy to source and try one for a short period as mosfets and fets are often inexpensive


Thanks Andrew

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Re: Bmw E39 M5. Coil Driver

Post by STC » Mon Sep 12, 2016 9:04 pm

according to datasheet your IGBT can drive more than 20A Ice so the measured component must be faulty...
Viktor
The car is now fixed. That image was take with either a faulty or wrong for this application.
why the emitter is at 14 volts and collector at gnd in your attached image?
Because the Coil is Ground Side Switched. The Collector Will be at Ground waiting for the Gate to open so it can pull the 14v to Ground and switch On the Coil.

With the Gate Closed, the permanent battery voltage would be present through the primary windings in the Coil all the way to the IGBT, No Current flow hence No Voltage Drop

victor2k
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Re: Bmw E39 M5. Coil Driver

Post by victor2k » Tue Sep 13, 2016 5:20 am

Hello,
My mistake,didn't see the post on the second page...
But the switched ground is on collector when a positive pulse is on the gate and emitter is allways on the ground
if your equivalent was a N-channel IGBT.
Regards

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