Can you guy's help out with a diagram and description for a

J

james

Guest
problem
---------
1.I fitted a digital dashboard from an Vauxhall Astra GTE into a Ford
Escort,all works great apart from the speedometer.

2.The Astra used a Transducer to send a pulse to the speedometer, I'm
told that the pulse rate is 1474 revs/mile for the Astra and 1000
revs/mile for the Escort.the escort has a spedometer cable and works
mechanically (now redundant)

3.I need a new way to measure speed, a friend suggested using a
reflective opto switch http://www.isocom.com/datasheets/db92074.pdf to
read a disk or driveshaft with reflective strips placed on it
producing the desired amout of pulses.how would i convert a 12v feed
to the desired input voltage. and what is an NMP amlifier? (i think
thats it)

3a Can a simple diagram be drawn up for a brainless twit to accomplish
this?

4. if anyone has any other ideas....feel free


and thanks for your time and some of your big brains\


James
 
wallsy@ntlworld.com (james) wrote:
problem
---------
1.I fitted a digital dashboard from an Vauxhall Astra GTE into a Ford
Escort,all works great apart from the speedometer.

2.The Astra used a Transducer to send a pulse to the speedometer, I'm
told that the pulse rate is 1474 revs/mile for the Astra and 1000
revs/mile for the Escort.the escort has a spedometer cable and works
mechanically (now redundant)

3.I need a new way to measure speed, a friend suggested using a
reflective opto switch http://www.isocom.com/datasheets/db92074.pdf to
read a disk or driveshaft with reflective strips placed on it
producing the desired amout of pulses.how would i convert a 12v feed
to the desired input voltage. and what is an NMP amlifier? (i think
thats it)

3a Can a simple diagram be drawn up for a brainless twit to accomplish
this?

4. if anyone has any other ideas....feel free


and thanks for your time and some of your big brains\


James
Click to expand...
Hi James

Please note; I'm not an expert in automotive mechanics.

If I were in your situation I would try to find an off the shelf solution.

Getting an optical signal off the drive shaft is possible.
In an automotive environment this may not be reliable due the possibility
of mud/dirt getting splattered on the reflective tape.
The speedometer cable or transducer signal usually comes from the transmission
in my experience.
If this is so,would the drive shaft provide an usable pulse per mile?

Failing an off the shelf solution I would start by removing the transducer
from the Astra and use the existing cable from the escort to drive it.
There are configurable ratio adapters (gear boxes) available to calibrate
the rpm of speedometer cables.
This may allow you to calibrate your speedometer.

Good Luck

Colin
 
<1042241977@127.0.0.1:7501> wrote in message news:<3f5840f5$1_1@127.0.0.1>...
wallsy@ntlworld.com (james) wrote:
problem
---------
1.I fitted a digital dashboard from an Vauxhall Astra GTE into a Ford
Escort,all works great apart from the speedometer.

2.The Astra used a Transducer to send a pulse to the speedometer, I'm
told that the pulse rate is 1474 revs/mile for the Astra and 1000
revs/mile for the Escort.the escort has a spedometer cable and works
mechanically (now redundant)

3.I need a new way to measure speed, a friend suggested using a
reflective opto switch http://www.isocom.com/datasheets/db92074.pdf to
read a disk or driveshaft with reflective strips placed on it
producing the desired amout of pulses.how would i convert a 12v feed
to the desired input voltage. and what is an NMP amlifier? (i think
thats it)

3a Can a simple diagram be drawn up for a brainless twit to accomplish
this?

4. if anyone has any other ideas....feel free


and thanks for your time and some of your big brains\


James

Hi James

Please note; I'm not an expert in automotive mechanics.

If I were in your situation I would try to find an off the shelf solution.

Getting an optical signal off the drive shaft is possible.
In an automotive environment this may not be reliable due the possibility
of mud/dirt getting splattered on the reflective tape.
The speedometer cable or transducer signal usually comes from the transmission
in my experience.
If this is so,would the drive shaft provide an usable pulse per mile?

Failing an off the shelf solution I would start by removing the transducer
from the Astra and use the existing cable from the escort to drive it.
There are configurable ratio adapters (gear boxes) available to calibrate
the rpm of speedometer cables.
This may allow you to calibrate your speedometer.

Good Luck

Colin
Click to expand...
thanks colin ill see whats available, but in the meantime i'm looking
for a quick fix,

any other suggestions?
 
wallsy@ntlworld.com (james) wrote in message news:<1ea13d0f.0309050952.3df58fe@posting.google.com>...
1042241977@127.0.0.1:7501> wrote in message news:<3f5840f5$1_1@127.0.0.1>...
wallsy@ntlworld.com (james) wrote:
problem
---------
1.I fitted a digital dashboard from an Vauxhall Astra GTE into a Ford
Escort,all works great apart from the speedometer.

2.The Astra used a Transducer to send a pulse to the speedometer, I'm
told that the pulse rate is 1474 revs/mile for the Astra and 1000
revs/mile for the Escort.the escort has a spedometer cable and works
mechanically (now redundant)

3.I need a new way to measure speed, a friend suggested using a
reflective opto switch http://www.isocom.com/datasheets/db92074.pdf to
read a disk or driveshaft with reflective strips placed on it
producing the desired amout of pulses.how would i convert a 12v feed
to the desired input voltage. and what is an NMP amlifier? (i think
thats it)

3a Can a simple diagram be drawn up for a brainless twit to accomplish
this?

4. if anyone has any other ideas....feel free


and thanks for your time and some of your big brains\


James

Hi James

Please note; I'm not an expert in automotive mechanics.

If I were in your situation I would try to find an off the shelf solution.

Getting an optical signal off the drive shaft is possible.
In an automotive environment this may not be reliable due the possibility
of mud/dirt getting splattered on the reflective tape.
The speedometer cable or transducer signal usually comes from the transmission
in my experience.
If this is so,would the drive shaft provide an usable pulse per mile?

Failing an off the shelf solution I would start by removing the transducer
from the Astra and use the existing cable from the escort to drive it.
There are configurable ratio adapters (gear boxes) available to calibrate
the rpm of speedometer cables.
This may allow you to calibrate your speedometer.

Good Luck

Colin

thanks colin ill see whats available, but in the meantime i'm looking
for a quick fix,

any other suggestions?
Click to expand...
Maybe to avoid the mud and hostile exterior environment you could hack
the existing mechanical speedo cable. Attach a magnet to the cable (on
the free, unused end) and a Hall effect sensor to pick up rotations.
All the sensitive bits could then be in the cars interior.

Arch
 
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