Nope not working, I reverted to the ugly setup but I might give it another go today

 

oh ok i got the impressions she was allgood where are you at woth it at this time ?

 

I thought it was better, I think I just improved it because theres still bad noise

 

a video possiable mate might give us a idea of the noise ?

 

Post your msq that you're using with the vb921's... also, did you rewire the way I said? It's not entirely clear from your post...

If you rewired the way I said, you'll want spark output set to "normal"

Ken

 

Yeah I've gotcha mate.

I've wired it up so many different ways now its not funny!

Right now its

330Ohm pullup on LED14, Both VBs hanging off the negative led lead with no resistors in series

the VBs are sitting in the proto area, they have their own isolated ground going straight to the ground I use for everything else

wired direct to the IAC pin header, so no current is passing through the pcb.

I attached my msq

 

200Ohms pulling up LED14, with the VB921 hanging in free air outside the MS case and they fire beautifully with no noise!

 

I forget, did you ever try reducing dwell? vb921's don't get that noisy until they start current-limiting.

Ken

 

I tried as low as 0.5ms but now that I know what works definitely I will give it one last shot internally

 

how are we getting on woth this i just finished building my board first time works beautiful on the stim im so happy first time doing it will post some pics of my work
right just need to sus this VB **** i think out of box pcb mounted with heat sink and high fieldality sheilded wire should cut the noise

have you adjusted the pots also is noise the only problem you are facing ?

my engine is currntly being built so it is hard to trial and error it


Thanks
Colin

 

They work fine outside the main megasquirt case.

200ohm pullup on the led driving the coils in wasted spark
330-400ohm pullup on the leds driving the 2 independant trailing spark

Nope you don't need to adjust the VR sensors to get that working, just do them completly counterclockwise like the FAQ says.

Heatsink the VB921's well, give them good ground a good wire to the Coil -ves (10A wire is probably prefered). Don't go overboard with dwell either,

more dwell drastically increases the heat the VBs disipate, which will kill them if you go too far.

 

do we know what dwell these can handle max any way there should be some sort of spec i was going to run my hec 715 bosch coil standard dwell

 

what firmware should i be using also 29V or 29Y

 

Use the one I listed in the Firmware thread in this section.

 

try between 2.6ms and 3.4ms for running.

Cranking can be high, like between 4 and 5.5ms I guess.

 

have you got any further with the igniton set up mate

 

nope but I'm still undecided if i will keep the VB921 or move over to FC coils. I suggest you just use FC coils

 

any further with this jobro ?