OT: tahograph pulse dividers

Thought i'd ask on here, as i imagine a fair few own vans (or landrovers who want to tow decent trailers for work), and some of them may have added a tachograph to them in the past.

Anyone know how much a tachograph pulse divider costs, as used to fit a tacho to a vehicle without having to fit a 4 wire tachograph speed sensor to the gearbox.

formatting link
i have e-mailed them for a price, but as usual it's the weekend, want to know if it's worth me fannying about trying to knock up a circuit to give me the signal i need, or stop before i break something and order the proper unit if it dosent cost that much.

Reply to
Gazz
Loading thread data ...

Just a thought:-

Jaycar do a speedo corrector really designed for those who have changed the final drive ratio etc on a custom car. It is a microprocessor which takes in the pulses from the gearbox sensor or whatever and alters the output stream by roughly from 1:1 to between 1:2 and 2:1 in small steps. I've also used this to drive speedos on cars where the gearbox has been changed to one with no speedo drive - by adding a sensor to the propshaft.

It's very inexpensive - 25 quid delivered as a kit, so you do need electronic skills to build it. It is very flexible in configuration so should take the input from any sensor and drive pretty well any of the common speedos, etc.

Reply to
Dave Plowman (News)

You don't know of a similar product for tacho adjustment, do you? Ever since I changed the TVR from Lucas to Omex engine management, the tacho has been ~20% adrift. The adjustment in the Omex is too coarse, so I can only get it within ~1000rpm either way. :o(

Reply to
Huge

Not tried, it but I can't see why it wouldn't work for that. 20% is well within its adjustment range. Does the Omex have a dedicated rev counter output? If so this is probably just a 12 volt square wave and would be fine. Off a coil, the signal can be 60 volts or so, and would likely need clipping to something closer to 12 volts or so.

FWIW, I couldn't get the (Smiths) tach on my SD1 to work properly from EDIS, so changed the actual driver in the instrument.

Reply to
Dave Plowman (News)

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.