Making my own heated grips controller

Originally Posted by lee67

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

would there happen to be one on the thou?

[embee]

Originally Posted by Alpinestarhero

.. 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'll post something here, others with more electronickery knowledge can add/correct/expand as necessary.

The Maplins "speed controller" is just a variable mark-space device, in other words it switches the output on and off rapidly for varying proportions of time, the output is at full supply voltage when it's on. I don't know what frequency it runs at, for a simple resistive load like heated grips it doesn't matter, but it's often in the kHz range. The relative proportion of on/off is termed the duty cycle (usually in percentage terms. e.g. 50%) or mark-space ratio or similar, the "on" pulse width is "modulated", hence the term "pulse width modulated" or PWM.
In this manner it controls the power the device gets supplied with, it doesn't rely on "wasting" energy in order to do it.

You'd need to measure the resistance (or current demand) of the grips to decide whether it would be adequate.
The current rating of this unit is probably determined by the output device, and I guess it could be uprated by either substituting a larger device (transistor/thyristor?) or using it as it stands to drive an additional one. This is where my knowledge runs dry I'm afraid.

If you are adept at wielding a smouldering iron you could probably rig the control pot remotely from the board, making it neater and possibly improving weatherproofing.

It'll probably be cheaper/easier to buy a purpose made unit, the better ones will be this type of control circuit anyway.

[Dave20046]

You ever get one sorted alpine?
As it's getting colder and I have hotgrips fitted to the bike I'm thinking I may aswell get them working. My old controller blew just as I bought the bike, so need either a DIY one or a proper one.

Right, forgot about this thread.

I complained to oxford customer services, who sold me one of the other analouge controllers at a discounted price (15 quid instead of 22)

If you are unhappy with your heated grips controller, moan to them. They may be good to you and help you out.

I took heavily into acount what embee said about how the controller works (it phases the switch on/off/on/off, not just constantly on and dumping the excess electrical energy as heat at the resistor) and oxford helped me out

So, i should have warm toasty hands this winter, hurrah

However, as a side project, i may look into making one, and then if it works I can make a guide and people can then use that guide and improve.

[fastdruid]

Hmm, when my Oxford controller died I got another controller for 5 quid from the bike show the other year. As it's also failed[1] I think I'll try and get another one from there!

Especially as at this rate of healing it'll probably be December before I get to ride a bike again. :-/

Druid

[1] Ish, you can sometimes get it to come on.

[ophic]

Just wire in a switch. Hands get cold, turn on. Hands get too hot, ride faster.

[Dave20046]

That's my thinking at the mo

Can anyone foresee any issues with this?
Less bulky then the crappy controllers too.

[ophic]

Originally Posted by Dave20046

That's my thinking at the mo

Can anyone foresee any issues with this?
Less bulky then the crappy controllers too.

it was a serious suggestion - just make sure the switch can handle the current. My grips are usually off or set to MAX. No point in owt in between, imho.

[Dave20046]

I know , I was being serious. I was considering it the other day just wondered if it made any odds. Can you get switches with an LED to indicate they are getting power? I don't see why not...

[ophic]

Originally Posted by Dave20046

Can you get switches with an LED to indicate they are getting power? I don't see why not...

you can, although i'd be more worried about getting a properly waterproof switch.