ELECTRONIC SPEEDOMETER INPUT

D

dleligdon

New Member

• Feb 12, 2015

• #1

Trying to replace my motorcycles mechanical speedometer with an electronic one. Many GM 27-168 stepper motors available for a reasonable price. I can not find a data sheet showing the type of input. ma, voltage, or pulse??? Using Adruino for processor.

Motorcycle is a 1973 BMW R 75/5 and NOS units are very expensive.

Thanks for your help, Dave

 

crutschow

Well-Known Member

Most Helpful Member

• Feb 12, 2015

• #2

Sorry, but I missed the connection between the availability of stepper motors for a reasonable price, no less, and an electronic speedometer.

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Feb 12, 2015

• #3

The missing connection: http://www.wholesalesteppermotors.com/main.sc

There is a blurb here. http://forums.adafruit.com/viewtopic.php?f=31&t=44663

 

Ian Rogers

User Extraordinaire

Forum Supporter

Most Helpful Member

• Feb 12, 2015

• #4

You don't need a stepper motor.... A simple DC hobby motor will generate a voltage that can be read on the Arduino..

I used one in an Anemometer project and it worked quite well....

Other than that a rotary encoder would serve you better...

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Feb 12, 2015

• #5

Ian:

i think you missed the point. The stepper motor drives the needle. How? Not exactly sure since i never had one apart. it COULD be a one of those funky gears like used in a hobby locomotive and a stepper. So, instead of a linear actuator like you have in a floppy drive, you get an angular actuator. I just don't know. All I know is they call them "stepper motors".

 

K

KeepItSimpleStupid

Well-Known Member

Most Helpful Member

• Feb 12, 2015

• #6

A better blurb. https://hackaday.com/2013/01/19/custom-gauges-with-a-stepper-motor-breakout-board/

 

debe

Active Member

• Feb 13, 2015

• #7

This is a page from VDO explaining how there stepper inst works.

 

Attachments

• VDO STEPPER MOTOR INST.pdf

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Ian Rogers

User Extraordinaire

Forum Supporter

Most Helpful Member

• Feb 13, 2015

• #8

KeepItSimpleStupid said:

Ian:

i think you missed the point. The stepper motor drives the needle. How? Not exactly sure since i never had one apart. it COULD be a one of those funky gears like used in a hobby locomotive and a stepper. So, instead of a linear actuator like you have in a floppy drive, you get an angular actuator. I just don't know. All I know is they call them "stepper motors".

Click to expand...

Then why is the title about reading the input???? Driving the electronic output will be the stepper driver, which isn't implied!!

Most gearboxes nowadays have a transducer that outputs frequency.... But "Mechanical" systems are still rotary cable...

 

debe

Active Member

• Feb 13, 2015

• #9

This is a stepper motor from a Ford instrument panel & its made by VDO. It used a custom VDO processor to drive it. The instrument panel was driven by the speed sensor on the transmission. It uses a Hall sensor to give a square wave output.

 

Attachments

• VDO INST STEPPER.1.JPG

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• VDO INST STEPPER.2.JPG

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• VDO SPEED SENSOR.1.JPG

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• VDO SPEED SENSOR.2.JPG

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D

dleligdon

New Member

• Feb 13, 2015

• #10

Thanks for all your help. I think VDO data sheet debe showed is what I need. I,ll check out the other links also. Being a retired mechanical engineer gives me a lot of time to tinker and learn how to do new things.

Thanks again, Dave