LT77 speed sensor

[Oldred_V8S]

Guys forgive me if this does not apply to the Wedge, but I am looking for a knackered LT77 speed sensor for a project to look for an alternative. I am making the assumption the V8 Wedge uses the LT77 box.

Please see:
http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Cheers,

Paul

[Wedg1e]

It does use the LT77 box and I think I have a couple of those sensors somewhere; one I dismantled to see what the workings were to provide the pulse train for the electronic speedo as it also drives the cruise control (I have the only cruise-equipped Wedge in the world! )

I can probably do you a circuit diagram if that's any help?

[adam quantrill]

You would be better off on the Chimp and Grief forums, 'cos wedges use a speedo cable, no sensor, it's all mechanical-loike.

[grahamw48]

I thought the hotwires did...in the engine bay.

[Barkychoc]

Hotwire does use the electronic sender as the signal also feeds the ECU so it knows when the car has stopped.

[Oldred_V8S]

Wedg1e said:

It does use the LT77 box and I think I have a couple of those sensors somewhere; one I dismantled to see what the workings were to provide the pulse train for the electronic speedo as it also drives the cruise control (I have the only cruise-equipped Wedge in the world! )

I can probably do you a circuit diagram if that's any help?

Ian I would take anything you can give me.

Many thanks,

Paul

[Oldred_V8S]

adam quantrill said:

You would be better off on the Chimp and Grief forums, 'cos wedges use a speedo cable, no sensor, it's all mechanical-loike.

Already done, but nothing back yet.

[Wedg1e]

Oldred_V8S said:

Ian I would take anything you can give me.

Many thanks,

Paul

Here you go:




PM me your email address and I'll send you the full A4 page that this is cropped from

[Oldred_V8S]

Wedg1e said:

Here you go:




PM me your email address and I'll send you the full A4 page that this is cropped from

Many thanks Ian. PM'd you.

[adam quantrill]

Yeah sorry - forgot about the hotwires (never had one, see?)

So what the blazes is that transistor doing on the right hand side - it's not biassed or anything? Just being used as a diode? Or is it really the Flux Capacitor ;^)

[grahamw48]

Is it something to do with the volume control ?

[Wedg1e]

adam quantrill said:

Yeah sorry - forgot about the hotwires (never had one, see?)

So what the blazes is that transistor doing on the right hand side - it's not biassed or anything? Just being used as a diode? Or is it really the Flux Capacitor ;^)

I suspect I didn't finish the drawing...
I just needed the nuts'n'bolts of it at the time to work out what sort of pulse train I needed to get the cruise ECU working.
That said, there are occasions when a transistor is used with one terminal open.
You think that's weird, you want to try working out what some stages of the injection ECU are doing...!