h4nd

I have several. The issue is getting very specific on the allowable models for which code, which chipsets, and if there's any crypto pairing or such bs. I've not looked at recent auto stuff, so gearing up could be a big time soak. Sorry, I'm out for the mo.

Car has been missing slightly the last couple of days. So I'm gonna drive it home to look for my spares...

Cool, so you'll be able to turn a knob, and like, change the wheelbase. Have been playing with these (Like WiFi, but slow, and ~10km range, and can run off a battery for a year...) https://nicegear.nz/product/adafruit-rfm95w-lora-radio-transceiver-breakout-868-or-915-mhz

Check charge V with a true-RMS meter?

Link?

The long cranking would be a problem. Initially I'm guessing a 4S lipo (14.8V nominal), because then you could use a standard alternator to charge (typically 13.8 to 14.5V). It won't fully charge the LiPo, but they don't sulphate and this will extend the working life. You'd need a cells balancer arrangement (available as a module, or in the plastic box per above). It'd probably be worth putting a relay on a thermo-switch on the battery, just as safety, (e.g. if battery starts overheating, disconnect the Alternator and starter relay circuits) (then car might continue to run on Alt). (+BATT)---+---(Batt Temperature RELAY)---(Alternator and rest of Car, incl starter relay drive) | (Start RELAY) (Starter) It'd need careful checking once built, to ensure safety, but should be good and light. Also, LiPo needs to be rated for the Alt charge rate.

I searched your thread, and couldn't find LiPo (or LiFePo). You mentioned wanting to drop the weight of the battery / cables, and you may like to look at those batteries. Even small ones have frightening output current capability, and you can get large capacity ones, though the $$ goes up. But, if you don't need lots of emergency reserve capacity the weight difference is Yuuge. I have one the size of two ciggy packets which''ll put out 3kW for 90s, at 20Volts. (Disclaimer, the charge volts are different, and the cells need to be properly balanced, or they catch fire...)

They'll do 10A, but they'll run hot. Diodes are cheap, get big-uns.

Yup. More detail helps with a recommendation. E.g, sizes of batteries, type of load, kind of supply / charger.

As drawn, you'll only get 5V - V(be) of the xststor (4.4v) over the inductor. When it turns off, there's no path for the inductor current to 'kick' voltage to the tach. It'll just try to maintain the steady current (if any). Probably easiest to put in the 2nd transistor as you're suggesting. Level translations can be surprisingly tricky. Good diagram BTW, nice n clear. (Hand sketch is good, too).

Ping me, bro

^ this, but, workmate has something like that in his camperbus, very pleased with it so far. Edit, combustion air is separate from heater air.

Windows? Eagle PCB gets used a lot, is limited to small output PCBs for free version, which shouldn't affect schematic only. KiCAD is full on industrial, free, but may not meet your easy to use criteria. I've been meaning to learn it for a few years, but I have Protel muscle memory, and libraries.

Measure current? Heater will suck bulk juice, and should be easy to see if it's intermittent. I have a clip on meter which'll do DC, you can borrow. Won't even need to undo the wire to put ammeter in circuit.

6mm! You wanted the bench gearbox proof? Looks damned good!

Interestingly, @yetchh and me were chatting about a small hand-held battery welder at Nats...

Have a pair 32mm dia, ~26mm long. Yours if you want em, I'll leave'm in the letterbox (P.M. inbound)

I may have a couple like that spare in the shed. How big? How many?

You may be up against ROHS (Reduction of Hazardous Substances) lead free "solder". It has no lead, and melts at a noticeably higher temp.

Yep, watch the radiant from the element, temp can be higher than on the dial.

I'm slightly surprised the CaFi got painted satin black. That's extra weight, yeah? Also, titanium fasteners go well with composites? Could one leave fibres unepoxied in a band to act as a hinge?

Sounds like early onset KeiCaritis. Heh.

Nice nice. also, if you really are running out of processor power: Arduino Due. 32bit processor, (not 8 bit) running at 84MHz , (not 16). Mind, it's 3V, not 5V, but basically the same footprint as the Mega2560.