oneTesla

Nope, I needed a ground for my scope, and I used the fan header, but the probe touched pin 1 and 2 simultaneously. (which is strange, because google just shows me that is the 12V and RPM connection, not the 12V and the GND)

I've had more trouble with the 15V regulators, but the previous one worked fine (as in: stone cold during operation) until I did the aforementioned. The whole coil was operating fine, I do not see how something would have failed.

There, I fixed the power supply, and it's working like before again.

Hadn't had much time of making a new primary, but I am thinking of a pancake or helix design, with a clamp to easily change the amount of windings. I need to find proper materials first, so the old setup will have to do.

I also need to get more coating/varnish on my secondary. It's only flashing over when I decrease the breakout too much, but I will feel better with a proper varnish anyway.

I have a new phone, with 120 slowmotion capabilities, and it's awesome to watch the oneTesla trow sparks at 4 times slower speeds! I tried a candle for effect of drawing the arcs better, but they chose the metal rim of the candle instead. Oh well.

Noise warning!

Hi, Bayley --

Just as a quick heads-up on those 3-terminal regulators, you have a lot of capacitance on the downstream side of those parts. 440 uF on the 7815 and 220 on the 7805, with the new 220 uF caps you're shipping. In my experience this isn't ideal with low-current loads, because at shutdown time those caps will discharge backwards into the regulators with potentially disastrous results. (When the pass transistor blows, it fails shorted, so the real damage is done on the next power cycle.)

Suggest using a combination of ceramics and smaller electrolytics in any future revisions; maybe move the electrolytics upstream of the 78xx parts.

More 'feedback' later (we just started our build last night and are having a good time so far!) But this would be my first suggestion if you have occasional unexplained failures of the 78xx parts.

At least on the 7815, the high capacitance is necessary; I've had passable results going down to 100uF per driver chip but any less than that and the 15V rail sags during switching periods.

Bayley wrote:At least on the 7815, the high capacitance is necessary; I've had passable results going down to 100uF per driver chip but any less than that and the 15V rail sags during switching periods.

Might consider a reverse-connected diode from the output to the input terminal, if the beefy output cap is necessary. (Or moving to a regulator with better load transient response.)

Probably no big deal, but it's bitten me before.