Temperature dependent wireless fault?

[DeF]

I've got a Trelock FC900 that I bought on a whim
from xxcycle when getting some other stuff.
For example, see http://www.bike24.net/p21559.html

Anyway, I put it on my MTB commuter and it has been
working fine until recently. When it gets cold, the
head unit doesn't get a signal from the sender. If I
take the head unit off the bars and move it close to
the sender, it works fine. I've replaced the battery
in the sender.

Any electronics experts who can explain this? I've
fixed it by moving the sender closer to the edge
of the rim but this means it's sticking out quite a bit
from the fork towards the wheel.

Cheers,
Duncan.


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[Marty]

DeF wrote:
> I've got a Trelock FC900 that I bought on a whim
> from xxcycle when getting some other stuff.
> For example, see http://www.bike24.net/p21559.html
>
> Anyway, I put it on my MTB commuter and it has been
> working fine until recently. When it gets cold, the
> head unit doesn't get a signal from the sender. If I
> take the head unit off the bars and move it close to
> the sender, it works fine. I've replaced the battery
> in the sender.
>
> Any electronics experts who can explain this? I've
> fixed it by moving the sender closer to the edge
> of the rim but this means it's sticking out quite a bit
> from the fork towards the wheel.
>
> Cheers,
> Duncan.
>
>
The distance these things work over is very short. I bought one with the
intention of using it on the back wheel. it didn't work, moving it about
150 cm closer and it worked. An earlier one I had wouldn't work when the
temperature got down to below 10 degrees C. Tried new batteries and
everything else, still didn't work. I've since given both of them away
and will never get another one again. I'm sticking with good old
fashioned wires.

Marty

[Claes]

DeF Wrote:
> I've got a Trelock FC900 that I bought on a whim
> from xxcycle when getting some other stuff.
> For example, see http://www.bike24.net/p21559.html
>
> Anyway, I put it on my MTB commuter and it has been
> working fine until recently. When it gets cold, the
> head unit doesn't get a signal from the sender. If I
> take the head unit off the bars and move it close to
> the sender, it works fine. I've replaced the battery
> in the sender.
>
> Any electronics experts who can explain this? I've
> fixed it by moving the sender closer to the edge
> of the rim but this means it's sticking out quite a bit
> from the fork towards the wheel.
>
> Cheers,
> Duncan.
>
>
> --
> e-mail:
> To reply, you'll have to remove finger.
The voltage from batteries drop when the temp drops. This means th
transmitter gets less power, and less reach. I think different types o
batteries are less or more sensitive to this than others.
NiCd is less sensitive than alkaline for example. Not sure what LiIo
works like. You could try to find a battery equivalent, that is no
LiIon, and that could help

--
Claes

[Bleve]

Some wireless senders have a strength change facility - the Polar ones
in particular do - you can open them up and flick a dipswitch and they
transmit further - and use more battery of course! My speed sensor
lives on my back wheel with no problems with both a Polar S520 and
S720. Maybe yours has some way to boost its signal?

[kingsley]

On Wed, 29 Jun 2005 11:49:08 +0800, DeF wrote:

> Anyway, I put it on my MTB commuter and it has been working fine until
> recently. When it gets cold, the head unit doesn't get a signal from
> the sender. If I take the head unit off the bars and move it close to
> the sender, it works fine. I've replaced the battery in the sender.

My guess it's a cold battery under-performing.
Can you take the whole non-functioning unit off, put
it in a pocket to warm it up, then try again in 15
minutes. Doesn't solve your problem, but shows it's
something to do with cold... Hmmm, guess you knew that
already.

-kt


--
Kingsley Turner,
(mailto: )
http://MadDogsBreakfast.com/ABFAQ - news:aus.bicycle Frequenly Asked Questions

[DeF]

kingsley wrote:
> On Wed, 29 Jun 2005 11:49:08 +0800, DeF wrote:
>
>
>>Anyway, I put it on my MTB commuter and it has been working fine until
>>recently. When it gets cold, the head unit doesn't get a signal from
>>the sender. If I take the head unit off the bars and move it close to
>>the sender, it works fine. I've replaced the battery in the sender.
>
>
> My guess it's a cold battery under-performing.
> Can you take the whole non-functioning unit off, put
> it in a pocket to warm it up, then try again in 15
> minutes. Doesn't solve your problem, but shows it's
> something to do with cold... Hmmm, guess you knew that
> already.
>
> -kt
>
>

My first guess was the battery in the sender was flat. I pulled
it out and compared the voltage with a new one - it was 1.5V down
from the nominal 12V new battery.

There is a little more to this story. When I got the unit, it wasn't
working. Turned out that the connection from the battery to the circuit
board wasn't working. Long story, but, I pulled it apart and soldered
a new home made battery connection. All a bit jerry rigged but it was
working fine. I might have to take it apart again. Damn.

Cheers,
Duncan.

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To reply, you'll have to remove finger.

[adam85]

DeF Wrote:
> kingsley wrote:
> > On Wed, 29 Jun 2005 11:49:08 +0800, DeF wrote:
> >
> >
> >>Anyway, I put it on my MTB commuter and it has been working fin
> until
> >>recently. When it gets cold, the head unit doesn't get a signa
> from
> >>the sender. If I take the head unit off the bars and move it clos
> to
> >>the sender, it works fine. I've replaced the battery in th
> sender.
> >
> >
> > My guess it's a cold battery under-performing.
> > Can you take the whole non-functioning unit off, put
> > it in a pocket to warm it up, then try again in 15
> > minutes. Doesn't solve your problem, but shows it's
> > something to do with cold... Hmmm, guess you knew that
> > already.
> >
> > -kt
> >
> >
>
> My first guess was the battery in the sender was flat. I pulled
> it out and compared the voltage with a new one - it was 1.5V down
> from the nominal 12V new battery.
>
> There is a little more to this story. When I got the unit, it wasn't
> working. Turned out that the connection from the battery to th
> circuit
> board wasn't working. Long story, but, I pulled it apart an
> soldered
> a new home made battery connection. All a bit jerry rigged but it was
> working fine. I might have to take it apart again. Damn.
>
> Cheers,
> Duncan.
>
> --
> e-mail:
> To reply, you'll have to remove finger.

The Polar sender units have a jumper inside which allows you to selec
3 different power output levels. Perhaps your unit has somethin
similar? On second thoughts maybe the jumper is to keep the batter
warm? :

--
adam85