Board Logo

Speedometers
Volkswagenboy - December 27th, 2005 at 03:28 PM

Has anyone any information on converting an analogue speedometer to a digital type?
Thanks.


modulus - December 27th, 2005 at 05:08 PM

Most air-cooled speedos are analogue, driven by a cable from the front-left wheel bearing; the speedo instrument itself makes sense of the rpm of the cable and indicates a speed.

An analogue speedo needs a digital signal fired every time something speed-related happens (e.g. every time a magnet on the output side of the differnetial passes a coil).

Depending where you're going with this you can either continue with the cable-driven speedo and get an instrument tech. to convert it to digital activation (but what is achieved?) or you can create a Vehicle Speed Sensor (VSS) using magnetic pickups on e.g. the flanges of CV joints which would then be suitable as input for a number of other instruments.

I'm building an electronic speed alarm for my Transporter at the moment, and I'll use 8 magents spaced around a CV flange to cause a pulse through a stationary coil as the speed input; this will give me a digital speedo as well as the speed alarm; I'm leaving the analogue speedo intact.

Other folk on this forum are trying to solve the problem of how to feed their VSSs for fuel injection systems. The Search button is your friend.

hth


Volkswagenboy - December 27th, 2005 at 08:26 PM

True, true.


helterskelter400 - December 27th, 2005 at 08:56 PM

$19.99 base model push bike speedo will do. you can of course spend much much more..., lengthen wires and inspect front brake/hub area with some liquid nails with the enclosed sensor and magnet.

an alternative, hardwire a gps in and mount it on dash......

edit
found it... here's a pic when i had the bike speedo on....

http://img.photobucket.com/albums/v282/helterskelter400/buggy/94309a0d.jpg

[ Edited on 27-12-2005 by helterskelter400 ]


11CAB - December 27th, 2005 at 09:26 PM

I see your a Cat lover Helterskelter.......:P


helterskelter400 - December 27th, 2005 at 09:45 PM

no, you got it all wong... i love cats... but only after they've been processed by the local chinese takeaway. haha


blutopless2 - December 28th, 2005 at 06:43 AM

i will eventually be doing this for my speedo when i change over to the VDO vintage series. The new speedo requires a digital signal. There is a converter which is used with this speedo that converts from the cable rpm to a digital signal which is wired to the speedo. I am intending to use a speedo place to set this up for me.