Making my own heated grips controller

[yorkie_chris]

Nothing built in on the loom on SV. A simple switch might be too hot but would work fine.

You need a voltage divider I think

pointy s has an accessoery socket in the loom up behind the headlight

[embee]

I'm not sure what current draw typical heated grips have.

This sort of thing would be suitable if it could cope with the current, this one is rated at 3A cont, 5A peak. It might be upgradeable with a replacement output stage for higher current, using the onboard duty cycle circuitry to control it. Being a duty cycle (PWM = pulse width modulated) type device it reduces the power efficiently (i.e. not by dumping) so easing the load on the bikes electrics.

Just a thought.

[SoulKiss]

Originally Posted by yorkie_chris

Nothing built in on the loom on SV. A simple switch might be too hot but would work fine.

You need a voltage divider I think

I would have thought that the rotary controller would have just been a potentiometer with it controlling the heat via the amount of current passed.

I guess you *COULD* do it via voltage tho...

I have Orford 'wrap around' heated grips that I only fit if riding any distance in the cold. They have a simple on/off switch. I switch them on, they get hot, and when my hands get too warm I turn them off for a while.

[ophic]

Originally Posted by SoulKiss

I would have thought that the rotary controller would have just been a potentiometer with it controlling the heat via the amount of current passed.

I guess you *COULD* do it via voltage tho...

you can't control current directly. V=IR

[SoulKiss]

Originally Posted by ophic

you can't control current directly. V=IR

True - but as R in that is variable through a Pot, then it was just clumsy wording by me :P

[ophic]

Originally Posted by SoulKiss

True - but as R in that is variable through a Pot, then it was just clumsy wording by me :P

The problem with a pot is the current handling. The heaters get hot - to stop them getting so hot you reduce the voltage applied and therefore the current that goes to them. Doing this with a pot means that any voltage not dropped across the heaters gets dropped across the pot - therefore the same power dissipated in the pot as in the heaters. What do you get? one hot pot.

I think you'd need some kind of power transistor (and a pot)

I have got through 2 of the old style switch boxes - first one developed a loud rattle and worked no-more, 2nd one was stolen. Had considered the new switch until I read terrible reviews of them and I realised that a physical knob (no sniggering at the back) was much better than buttons.

Interested to see/hear what you come up with.

Well i have been on the emails to oxford, they'll sell me an old style analouge one for about £14, discounted as a good-will gesture (I asked, they said ok).

Still rather make my own controller. I'm aware a simple potentiometer / variable resistor would get hot. Embee, I think I understand what you're on about, but im not completly certain...maybe you can PM me with what you mean in a more numpty-friendly langauge? I noticed the old analuge controler I had did have a sort of micro circuitry board, I suppose this was to pluse the power, not have a constant load and hence constant battery draw?