SIP Lambretta Digital Speedo

[sideout]

.....I wonder if the Wassel DC pioneers on here have got any clever ideas for a work around? Or is the future AC?....

Has anyone actually tried connecting to a Wassel DC set up with the rev counter feed connected to the DC output from the Wassel unit? maybe there is enough 'ripple' in the DC to trigger it, can't do any harm to try it in any case. If the battery smooths the DC out too much I wonder if inserting a diod into the possitive lead from thr Wassel and attaching the rev counter 'downstream' (isolating the batteryt) would work?
Does the technical specification for the SIP speedo give any info on the AC signal requirements for the rev counter? If it'll take up to 30 odd volts then connecting to the unregulated side of the Wassel unit would work. If not then it might be possible to work out some kind of voltage reduction arrangement.

Any thoughts on either of the above J1MS or Firekpd??

Coaster.

It's been a while since you posted the above, but I've finally got around to testing it
Disconnected the battery and the Rev Counter part of the SIP speedo sprang into life
So now for a suggested solution using your diode idea (I'm only a simple mechy and haven't done electronics for a while either )

Sorry about the diagram, I decided it was a good idea to draw it using Excel......



Is there a grown up out there who could confirm that a diode placed before the battery would allow clean ripple-free DC on the battery side of the diode to feed the lights etc., and the Wassel side of the diode would still contain the vital ripple signal to trigger the Rev Counter?

[Train Driver]

These speedo's aren't fit and forget like everyone wanted so are they worth the hassle.
They don't seem to work on a/c d/c or with the wassell conversions, or is it just over here and they work ok over on the mainland

[coaster]

.....I wonder if the Wassel DC pioneers on here have got any clever ideas for a work around? Or is the future AC?....

Has anyone actually tried connecting to a Wassel DC set up with the rev counter feed connected to the DC output from the Wassel unit? maybe there is enough 'ripple' in the DC to trigger it, can't do any harm to try it in any case. If the battery smooths the DC out too much I wonder if inserting a diod into the possitive lead from thr Wassel and attaching the rev counter 'downstream' (isolating the batteryt) would work? Does the technical specification for the SIP speedo give any info on the AC signal requirements for the rev counter? If it'll take up to 30 odd volts then connecting to the unregulated side of the Wassel unit would work. If not then it might be possible to work out some kind of voltage reduction arrangement. Any thoughts on either of the above J1MS or Firekpd??

Coaster. It's been a while since you posted the above, but I've finally got around to testing it Disconnected the battery and the Rev Counter part of the SIP speedo sprang into life So now for a suggested solution using your diode idea (I'm only a simple mechy and haven't done electronics for a while either ) Sorry about the diagram, I decided it was a good idea to draw it using Excel...... Is there a grown up out there who could confirm that a diode placed before the battery would allow clean ripple-free DC on the battery side of the diode to feed the lights etc., and the Wassel side of the diode would still contain the vital ripple signal to trigger the Rev Counter?

That's exactly what I was thinking sidout, it should work but the diode will need to be able to take the current pulled by the lights and horn, something like this should do you
Basicaslly the diode should allow the battery to 'see' the feed from the wassel unit but the diode will block any current comming back from the battery which would have the effect of smoothing out the ripples......hopefully. if it works maybe Byron will add it to the definitive DC wiring diagram as an SIP option.

Now get your soldering iron out , good luck
Colin

[sideout]

That's exactly what I was thinking sidout, it should work but the diode will need to be able to take the current pulled by the lights and horn, something like this should do you
Basicaslly the diode should allow the battery to 'see' the feed from the wassel unit but the diode will block any current comming back from the battery which would have the effect of smoothing out the ripples......hopefully. if it works maybe Byron will add it to the definitive DC wiring diagram as an SIP option.

Now get your soldering iron out , good luck
Colin

Got to get the diode first
Checked it out with the Leccy boys at work today who agree it should work.
I'll report back

Nigel

[CANbus]

Sideout, just wondering did you try the brown on the yellow from the stator?

[sideout]

Sideout, just wondering did you try the brown on the yellow from the stator?

Hi CANbus,

I haven't tried it with this device, but in the past I have measured the raw output from the stator and it can get quite high. So high that I've burnt out a previous tacho So I'm a bit wary of going there, at least just yet
Anyway, the diode Coaster recommended is on order, so I'll keep you posted.

Happy St George's day everyone :bouncyeng:

Cheers,
Nigel

[fsmlittler]

Just tried mine with the temp sender disconnected and it's working again. It worked with the temp sender connected but not attached to the plug so could there be an interference problem?

[sideout]

The diode arrived today so I connected it in accordance with the circuit posted earlier. Result.... No good

I didn't get a chance to play around very much tonight, but I'll carry out a more in depth experiment when I get a chance.

So, in summary so far:
- connected diode between output of Wassell +12V and battery positive
- connected brown wire on speedo to Wassell +12V side of the diode
- speedo red wire still connected to battery +12V
- result: speedo powers up, rev counter sweeps and returns to zero. Start engine - speedo functions light up but no rev counter.

Disconnect battery:
- speedo and rev counter works

Conclusion:
- with the battery in the circuit the brown wire is not seeing the AC rippled DC feed from the Wassell.... :wtf:

Next:
- Isolate everything else and just have the speedo, rev-counter connections and battery in the circuit
- add circuits one at a time until I track the problem

Any suggestions or helpful hints will be gratefully received

[coaster]

Did you try it with the diode the other way round?......clutching at straws but worth a try :wtf:

If the diode is the wrong way round, the SIP speedo would still get its DC feed from the battery but the diode would block the feed (with ripple) to the battery.....maybe?

[sideout]

Did you try it with the diode the other way round?......clutching at straws but worth a try :wtf:

If the diode is the wrong way round, the SIP speedo would still get its DC feed from the battery but the diode would block the feed (with ripple) to the battery.....maybe?

Straw clutching carried out Colin! I tried connecting the diode around the other way, and also, because I've got an ammeter I can see when the Wassell is charging the battery.

I did try connecting both red and brown to the Wassell feed with the battery disconnected and that worked fine. I think I just need to play a bout with it and take a long hard look at my wiring!

We've got visitors for a few days so garage time will be at a premium now

Don't give up on this, it's a nice bit of kit!