14
User ManUal
v1.6
If the spark sounds
hissy or crackly…
If it makes a
loud bang upon
plugging into AC
power...
n
Try moving the antenna around. Bringing it closer to the
coil often improves performance, but remember not to
bring it too close, or you will get arcing to it.
n
Check your grounding. The top of the secondary to
the ground pin of the power cord should read ~600Ω.
If it reads significantly higher you have a break
somewhere which you need to hunt down and fix.
n
Consistent poor performance despite hearing gate drive
buzz (see Step 15) can indicate an issue with gate drive
signals. Check your 15V rail carefully.
n
You may have a bad solder joint which is picking up noise
and affecting your driver’s logic signals. Inspect your
soldering on both the interrupter and the driver board. It
never hurts to re-flow your joints with a good iron to fix
potential cold joints that are near-impossible to see.
n
Your USB cable may be poorly shielded and may be
picking up noise.
Keep in mind that a little bit of hissing or crackling is inherent to
the operation of the coil, and that audio quality will not be perfect.
See, this is why we tell you to plug your AC cord into your coil
first, then into an outlet! Fortunately this failure mode really isn’t
likely to occur if you inspected your board properly and did a
multimeter check of your IGBTs.
Probable causes of this failure mode include the following:
n
IGBTs not properly isolated from the heat sink with
sil-pad. Or, you used a metal screw instead of a nylon
screw to fasten your IGBTs.
n
You installed an electrolytic capacitor backwards,
resulting in the capacitor blowing.
n
A catastrophic solder bridge caused a short that made
your fuse blow instantly.
n
You plugged in your coil while the interrupter was
latched up at 100% duty cycle.
n
You plugged in your coil without the interrupter’s cable
installed, resulting in continuous light entering the optical
receiver, latching up the coil.
Unplug your coil from AC power immediately, wait 5 minutes
for the capacitors to discharge, and then examine your board
carefully for errors. If you’ve made a catastrophic assembly
mistake you should probably get help from somebody with
more experience.
