Some open source antispark designs that work

Gamer43 · August 17, 2019, 12:01am

Since I keep seeing this come up.

https://easyeda.com/RuBisCO/On_Switch-2610688072df43d9976cee88fc640fe3

https://easyeda.com/RuBisCO/LowsideSwitch

They both work. The first one is easier to assemble on PCB and I trust it a lot more by virtue of high side switching

The second one is easy to build on protoboard, no need for a PCB.

Both have been tested by members of the community, I can cite their testimony if someone wants.
There could still possibly be issues, if someone makes these and encounters one, please let me know.’

BY THE WAY. The first switch will fail with an output capacitance greater than 6,000uF.
The second one may need tuning with the precharge resistors if the quiescent current is too high.

Both require a latching pushbutton, I recommend this one from adafruit:

Some smart antisparks are on the way in the near future.

stratoglide · August 17, 2019, 4:36am

I’m not sure how easy or difficult it is but is a momentary switch an option/addition.

Having my brakes and acceleration dependant on a latching switch terrifies me.

skelstar · August 18, 2019, 6:33pm

Fair, but having software that maintains the switch’s “state” terrifies me a little too

stratoglide · August 18, 2019, 6:39pm

At a minimum I believe that the on state should be the “relaxed” state of the switch so a spring isn’t constantly trying to turn the board off.

Or a rocker style switch that isn’t constantly trying to turn itself off would also be much less terrifying.

Gamer43 · August 18, 2019, 6:57pm

Actually yes, rocker switch would be best.

itsrow · February 13, 2020, 11:25pm

Any chance you extras of these you want to sell? If not, do you know what switching diode I should use to populate the high side switching switch (hehe) thats the only one I couldn’t really figure out.

Gamer43 · February 13, 2020, 11:38pm

Any 200V 5A diode, with maximum forward surge current higher than maximum battery current. use digikey’s search tool and pick one you like.

itsrow · February 14, 2020, 12:05am

Appreciate it, thanks

itsrow · February 14, 2020, 12:49am

If I were to use this under 90A would I be on the right track? Diodes are really not my specialty but I’d be happy to share my BOM to update the original post so everything is in stock and all from mouser. Massive thank you for making this open source from schematic to gerber, I tried making my own antisparks and It costed me at least 3 VESCs (lmfao) so I’ll leave it to the pros.

Gamer43 · February 14, 2020, 1:41am

Should be fine. It is basically there to protect the switching circuit if for whatever reason it turns off with load.

itsrow · February 14, 2020, 1:45am

God bless you, ill toss the components into a google docs list and toss them here tonight.

itsrow · March 1, 2020, 8:51pm

Components and mouser link, slightly changed the list to make it more readable and more fluid, I’m making a whole bunch of these and everyone should feel free to try themselves. Get PCBs from JLCPCB everything else is a mouser purchase.

@Gamer43 Let me know if you want me to change anything.

Gamer43 · March 1, 2020, 9:18pm

Use the TPW1R306PL,L1Q MOSFET. But really, any MOSFET will work, so you can pick one you like.

itsrow · March 1, 2020, 9:18pm

Will update that right now.

Gamer43 · March 1, 2020, 9:23pm

Make sure to update the footprint on the PCB

itsrow · March 1, 2020, 9:31pm

Added a footnote stating the alternative option for fets but stating you’d have to change the footprint of Q1 and Q2 in order to use the toshibas.

Edit: Im surprised this has flown under so many peoples radar, its the best minimalist antispark I’ve ever used.

itsrow · March 5, 2020, 11:59pm

Any chance I could get you to look this over? I can’t tell which way to position the switch driver but I’m pretty sure it’s right. Anything stand out to you? I could not get it to function and this is my second PCB Unless it needs a voltage higher than 7.6v to run.

Gamer43 · March 6, 2020, 2:00am

Yes, it needs at least 12V, the gate driver goes into UVLO below 8 or 9V, and the regulator has some dropout.

MAKE SURE THE LTC7004 EXPOSED GROUND PAD IS PROPERLY SOLDERED, IT IS GROUND FOR THE CHARGE PUMP CIRCUITRY.

itsrow · March 6, 2020, 3:19am

I still can’t get it to work, 0 voltage on the other end and I can hear the caps sparking when I plug it in, any chance I could steal a picture of one of yours? I still think my switch drivers backwards.

Gamer43 · March 6, 2020, 10:40am

The chip is soldered correctly, check to make sure all relevant voltage rails are present