H5 speedo / servo driver

**Mouldy** · 19th July 2009, 15:20

Hi,

Im after a george francis H5 to use as a spair if i ever fix the one ive got thats broken.

It seems like these are like gold dust, the only people who seem to use them anymore is me and grant cooper and maybe ed hoppit?- if anyone out there has one sitting about please contact me, even if urse is blown up i might be interested.

Regards
Dave Moulds

**m2xt** · 19th July 2009, 19:45

Hi Dave, I'm sure I have got a couple of the H5's in my drawer at the workshop. I'll check tomorrow to see if they are H5's as there was two models IIRC. Really nice controllers, just never got around to using them.

**blazerbotics** · 19th July 2009, 20:26

Does anybody make an interface board that goes between RX and speedo, to create a jumbo servo? Surely it wouldn't be too complicated and means you could use anysize speedo.

**Mouldy** · 19th July 2009, 21:18

Paul - thanks id appreciate that, Although im sure i remember you saying you used H6's in TKM2 if thats were you think you have them?

Alan- if you find one let me know lol, that would be alot easyer. The only other alternitive ive seen to the H5 is the pololu board technobots sells.

If anyone knows of anything similar that can handle 10amps then id appreciate it.

Cheers

**mark_m** · 19th July 2009, 21:56

I tried making one recently using a sabertooth and a picaxe. Easy to do but the update rate is to slow for a quick servo. I was using a drill motor and gearbox as the output with a ten turn potentiometer. So to the picaxe it should have looked like a ~90rpm servo (~0.1sec/60degrees) but it was too fast and the ADC resolution too low - it kept oscillating unless I made it slow down a lot. I've got plans to try again with a faster microprocessor which should be no more difficult.

**woody** · 20th July 2009, 11:15

It's entirely possible to use a std r/c servo board as an interface.

http://130.94.182.150/mowers.htm

BUT as Mark said the driven motor/potentiometer speed needs to be fairly slow.

**Mouldy** · 20th July 2009, 12:40

yeah, slow is the problem, i worked out that it should selfwright in 0.8 seconds..

If paul hasnt got any H5's ill probably just go for an electronise 12amp with limit switches...

**m2xt** · 20th July 2009, 17:00

Hi Dave, you have a better memory than me, yes I have a pair of H6's that must have been used in TKM2. I did find a single H5 though, I would have to dig out some instructions to make sure it still works though. As for your other thread, the regulator is a 15V low drop out type and is generally available. Technobots do the 5V and 12V versions but not the 15V one although I can get them. You just need to source a LM2940CT-15.

I think I need a clear out as I seem to have quite a few spare bits in my personal stash, even the odd new Roboteq or two!