Making my own heated grips controller

Not directly related to how you do it, but just to add my twopennethworth: I think off, warm and warmer is plenty of control. Coming from an "infinite" range of settings on my previous bike, I thought I'd miss it, but it's fine.

[Dave20046]

Originally Posted by fastdruid

Depends, it should have been installed with it's own fuse so that if it went it didn't blow the main fuse...

Big fat slap for whoever installed that!

In which case, I personally would install a new fused wire from the battery + to one relay connector, then use the existing wire from the ign to the activating coil of the relay.

Druid

Shh he'll moderate you
Sorry to be a **** but someone's going to have to explain relays to me (or a link? ) I've never wired one in or ever seen one so lost on the 'activiating coil' bit. Or would it be self explanatory when I buy a relay?

[fastdruid]

Originally Posted by Dave20046

Shh he'll moderate you

lol, I stand by my words, a failure of the heated grips should NEVER leave you stranded.

Sorry to be a **** but someone's going to have to explain relays to me (or a link? ) I've never wired one in or ever seen one so lost on the 'activiating coil' bit. Or would it be self explanatory when I buy a relay?

Quite alright, not being an **** not to know something!

Ok so a relay essentially is just a switch except that instead of someone flicking the switch an electromagnetic coil does the work, so you have exactly the same wiring as a switch (including all the same options, SPST, DPDT etc) plus two extra connectors for the activating coil. The normal way to do things is to have a low voltage manually switched which triggers a far higher voltage switched by the relay.

Have a look at http://en.wikipedia.org/wiki/Relay but if I may steal an image off there;




The curly bit on the side is the activating coil, you'd typically use a SPST for this kind of use and connect 'A' to a fused wire from the battery, 'B' to the heated grips and then the activating coil as previously mentioned linked to earth and through a switch to a feed that is on when the ign is on.


Druid

[ophic]

Originally Posted by fastdruid

The normal way to do things is to have a low voltage manually switched which triggers a far higher voltage switched by the relay.

In this case its for current, not voltage - you can use a puny small switch to control the relay, which can, if necessary, be a big chunky high current device tucked away somewhere.

If I was doing it the first time I'd keep things simple with just a big switch instead. If I was doing it a second time i'd probably do something flashy like this.

You could get REALLY clever and use a temperature sensor instead of a manual switch

[fastdruid]

Originally Posted by ophic

In this case its for current, not voltage - you can use a puny small switch to control the relay, which can, if necessary, be a big chunky high current device tucked away somewhere.

Ooops, yes, I meant current Although it can also be for voltage, eg a 12v switch operation 240v.

Druid

[fastdruid]

Originally Posted by ophic

If I was doing it the first time I'd keep things simple with just a big switch instead. If I was doing it a second time i'd probably do something flashy like this.

My next clever thing I think of doing is rigging up heated levers, I find that the heated grips are ace but if your in any situation where you've covering the brakes or having to use the clutch a lot my fingers suffer. I could just use muffs but they look crap, I like the idea of just being able to turn it on of a chilly evening.

You could get REALLY clever and use a temperature sensor instead of a manual switch

Could be tricky.

Druid

[ophic]

Originally Posted by fastdruid

My next clever thing I think of doing is rigging up heated levers

There could be a market for those you know. I suffer similarly. Although my heated grips don't get hot unless my hand is wrapped round them, so levers could suck a lot of power.

[fastdruid]

On another thread I posted a link to the wikipedia page for PVM, at the bottom was a link to this page
http://www.eleinmec.com/article.asp?28 which describes a simple circuit using two 555's and a TIP31C, total cost is given as £7.35 (but I don't know how old it is) and should be able to cope with 40w or about 3A

Now 3A is possibly a bit low as Oxford say the grips pull "under 4A" but replace the TIP31C with something higher rated such as if I'm reading the table correctly a BD243C and you could have something, bit of strip board, some potting compound and some connectors and you have a controller. I think I may be making a maplins order...

Druid

[Dave20046]

I think I'm going to cave and buy the oxford thing I've not even got to fitting the circuit and stumbled at the first hurdle.

Just as a headsup, if you're looking for an on-off switch, the wraparound version has exactly that. Might be worth looking for a busted version of those as an alternative.