Airhead electric's/electronics question

[Wreford Miles]

My Airhead runs a TT IMO which has been great but recently the LED screen has taken to greying out as the rev’s rise.

I’d assumed it was some kind of HT interference but that’s not the case, what I have been able to establish is:

• If I belt off using a lot of revs its greys out and stays like it
• If I’m taking a calmer pace the screen starts to grey out but if I put the lights on it lightens and if I go to main beam it lightens more and if I put the heated vest on it lightens even more and will stay like this unless I give it some beans

So this is making me (and my non teckie/eleckie mind) think the higher voltage been created from the alternator at higher revs is causing the greying out of the LED panel and switching things on that use the power being generated and stops it or at least reduces it, so what’s allowing or should be controlling the higher voltage being generated?

Is there something that controls the voltage that I should look at? Or any other suggestion…

• It’s had a new diode board, but it did the same with the last one
• The connecting block for the IMO and TT warning light block has a diode, which I seem to remember is to do with the charge light led in the TT block not offering the same resistance as a normal charge light bulb

Cheers

 

[bumpmuncher]

My first suggestion is, go for a ride with a volt meter connected to the feed for the imo (or set the imo to read volts if it has this function) and check your theory about voltage. Then if theory confirmed the reg/rectifier will need checking for voltage, voltage will depend on type of reg/rect you have fitted.

 

[MickDB1]

I would also check yer have a very good earth to engine - my last one did similar and thats what it were
Good Idea with airheads is to have a earth from headstock to engine anyway ( so I was told and dooooo)

 

[Rob Farmer]

Page 10 of the Imo manual says the supply voltage can be anywhere between 9 and 17 volts. http://www.touratech-usa.com/media/gSUQSk/09-011-0011-1.pdf

You could buy two of these for £1.25 http://www.ebay.co.uk/itm/L78xx-Ser...or-5V-6V-9V-10V-12V-15V-18V-24V-/130836774030 (the 2 pack 12v)

This will give you a nice stable voltage to feed the imo. They are rated at 1A which is considerably more than the Imo's 150mA draw.

Connects like this. Ideally you'd have a couple of capacitors but for simply proving things on the bike it will be fine as it is.

If your not sure about making one let me know what type of plug you have and I'll run one up for you (FOC of course)

 

[Wreford Miles]

I'll check how it all connects up at the weekend... Thanks for the ideas

 

[ahutcheon]

Sounds like the IMO has its own regulator, and if the bike supply is getting above 17V you're going to need a new battery pretty soon... Bad earth sounds like a good one to investigate. Good luck!

 

[Wreford Miles]

The great thing about this site is you learn stuff...

 

[electric_monk]

The great thing about this site is you learn stuff...

Thats all well and good but do you remember any of it.....!!

 

[Wreford Miles]

Thats all well and good but do you remember any of it.....!!

Remember what?

Oh yeah, sorry I forgot what I'd posted!




Sent from my iPhone using Tapatalk

 

[Wreford Miles]

Well The suns out so it was time I got to the route cause...

Volt meter on and revved it and it showed more than 17v

In my box of bits I found a new thing'y bob in the picture and once connected it was showing circa 14 when revved and most importantly the IMO does not great out - Result

 

[Rob Farmer]

Police regulator. If you haven't got a load (lights etc) then expect a fried battery at some point.

 

[Wreford Miles]

Police regulator. If you haven't got a load (lights etc) then expect a fried battery at some point.

Cheers I'll keep my lights on...

 

[Paul Rochdale]

The great thing about this site is you learn stuff...

OK, WTF is a TT IMO?

 

[Rob Farmer]

Touratech speedo/revmeter unit.

 

[PW Cymru]

What would a police reg be putting out without a load on it?

I had one fitted on my RS recently and even with lights on it went way up into the red.

 

[Wreford Miles]

What would a police reg be putting out without a load on it?

I had one fitted on my RS recently and even with lights on it went way up into the red.

It says 14V on it, I thought they just allowed charging at lower revs the idea being police bikes may spend time pottering around town at low revs

 

[Beemerboff]

EME in the states sells an adjustable voltage regulator for around $25- which works perfectly - it can be set up a little if required by your new tech battery , or lower if you are having a overcharging problem.

Other folks have them , but at at three or more times the price, so you can buy a set of his low cost heavy duty battery leads,and a few of his other goodies, a few plugs and filters and still be well in front, even with the postage.

 

[PW Cymru]

[SUP][/SUP]

It says 14V on it, I thought they just allowed charging at lower revs the idea being police bikes may spend time pottering around town at low revs

Yes that's what I thought but I had one fitted to my RS and the volt meter kept going into the red at mid-range revs even with the lights on. As has been said earlier I was concerned I'd fry the battery if left for long periods.

 

[Rob Farmer]

They run a higher terminal voltage to compensate for the load of a police radio etc. You cannot really charge more at lower revs since the limitation is the what the alternator will kick out. The only way to get more at lower revs is to fit a larger alternator.

I ran the police regs on a couple of bikes and had battery problems on both, cured by fitting standard regulators. If you have a dry powder battery that run higher voltages I think you will be fine. BMW had a lot of flak about the charging systems, i'm sure if a simple regulator change would have cured it they would have done it from the factory.