EEVblog 1419 - Sinclair C5 Restoration - Part 2 - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: September 18, 2021, 12:54:27 pm
content: RIP Sir Clive Sinclair.Dave finally gets around to starting to take apart and restore the classic Sinclair C5 electric vehicle.

author: coppercone2
author_rank: Super Contributor
timestamp: September 18, 2021, 06:10:04 pm
content: rolling dirty on that contraption with a bottle of jack on the starship enterprize. i think it needs a starfleet logo. and magnetic wheels for 0 gravity driving

author: floobydust
author_rank: Super Contributor
timestamp: September 21, 2021, 05:11:35 am
content: The subframe cracks, maybe ask AvE for suggestions but Malcolm Faed's C5 in EEVblog #501 also has the same tearing 14:33. It's like unintentional torsion bar suspension lol.The Ferranti ULA IC's battery low voltage alarm at 12.5V seems high, today we run a UPS battery down to say 10.8V

author: thm_w
author_rank: Super Contributor
timestamp: September 21, 2021, 08:28:17 pm
content: Quote from: floobydust on September 21, 2021, 05:11:35 amWay too high, as soon as you hit on the gas it would dip below that.QuoteApparently the original battery was 35Ahr, range of 20km, motor 200-250W. But this PDF says they'd only get a useful 15-28Ah out of it (340Whr)..https://erik.gjermundsen.net/PDF/C5-SM.pdfQuotewowIf you completely strip out all that original electronics and motor and replace it with modern tech. Would easily be 2-3x performance improvement with the same weight.All of these parts are commodity, since you could grab a controller and battery from say an electric scooter (350-500W controller with regen, 300-500Whr battery).Ton of work though..

author: floobydust
author_rank: Super Contributor
timestamp: September 21, 2021, 10:02:48 pm
content: C5's have a cult following or something. Turn signals, mud flaps, horn, side mirrors, reflective stickers and Hi-vis mast - all were options.I woke up thinking it has no regen ability at all? Then I see D4 the 1N4001Somebody beat us to it, aMCU-based replacementfor the ULA chip. I'll say the board has no -ve spike protection for the LM78L05 so a bit fragile... the LM358 in the Control Box dies a lot too they say.

author: thm_w
author_rank: Super Contributor
timestamp: September 22, 2021, 08:48:51 pm
content: I would never have expected it to have regen. On devices this light and small it doesn't make a huge difference though. The nicest part of regen really is it takes load off of the brakes and extends their life massively. If its a 1N4001 though.. lol it won't be doing much.QuoteI guess we know why that belt pulley was broken:Quote

author: Kleinstein
author_rank: Super Contributor
timestamp: September 23, 2021, 07:12:46 am
content: The motor is connected by a kind of free-wheeling link, which is needed so one could paddle faster than the limited motor speed.So regenerative braking would also need some mechanical parts.It would also need some kind of boost converter to bring the voltage from the motor up to the battery level. Otherwise it would only work at high speed.

author: floobydust
author_rank: Super Contributor
timestamp: September 23, 2021, 08:10:28 pm
content: I don't think it has a 'mechanical' diodeThe gearbox is a planetary but I see no clutch or reverse ratchet (aside from at the pedals/chain). Looking at the Control Board schematic:No Reverse- or reverse movement, based on diode 1N5401 D1. They say the diode smokes if it's pushed backwards at anything faster than a crawl.It's weird with Sinclair stuff, it always has a lot of science when you dig in, if you can push aside the practical aspects being a bit weak.I think it's the first 1980's Coulomb counter I've seen, in the Fuel gauge. Lots of measurements on the speed, torque, range, acceleration, hill climbing etc.Like everyone went along with the Emperor's plan- not saying anything about his clothes. Perhaps for the business and money you'd do this kind of work.