...The never ended story of my Smiths speedo

baz said:

I am of the opinion it could protect any igniter box from regulator failure etc

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Yes that particular one protects from both over and under voltage, some only do the under voltage so will not cover regulator failure.

Efficiency varies both from what components are being used and the work being done but it should be 90+%.

Triton Thrasher said:

Says maximum 6 A. Enough for your RITA?

If the converter is 80% efficient, then it’s a bit power-hungry itself.

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Yep one of the reasons I fitted it was when the battery was a bit low and cranking slow the bike wouldn't fire immediately as it does now
I am a complete electrical dunce but I'm guessing as the engine actually starts to turn with the starter the voltage would climb a little and allow the Rita to fire?
Where as now it fires immediately as long as the motor turns over

Triton Thrasher said:

If the converter is 80% efficient, then it’s a bit power-hungry itself.

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The listing add claims 96%, which is astounding. I designed power supplies / battery chargers / DC-DC converters for 7 years early in my EE career and 85% was considered to be very good. Of course that was back in the 70's and technology has come a long way since.

baz said:

https://www.ebay.co.uk/itm/401227155899 you could fit one of these Yves
As long as your voltage dosent drop below 8v when you use the starter you will have 12v at the Speedo
I use one of these on my commando after Komando's recommendation
It ensures my power hungry Lucas Rita gets 12v when I press the starter button
I am of the opinion it could protect any igniter box from regulator failure etc
No doubt someone will correct me on this

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Hi Baz,
Very intresting, thanks.
The speedo cut off below 8.5V and you say "as long your voltage dosent drop below 8V when you use the starter you will have 12V at the speedo"
I think my voltage drop around 8V when using the starter, so not sure your stuff wil work.
To day I make a independant swift button for the speedo and it works!
I need to start the engine first and after swift the speedo on.
I set the PPU to 1975 pulses
I lift my back weel, start the engine, put in second gear, swift the speedo and the pointer move to 60 km/h, so far so good...
As soon I will have a day W/O rain I will do a Drive to set;
Keep you posted
Yves

Excellent. We all hope you get this sorted. Then post a summary of what you learned.

yves norton seeley said:

Hi there,
weeks of rain change the ground facing my workshop in a mud pool and dont allow me to go out to do a drive to set with my speedo.
I put 15 tons of gravel over the ground and now it's dry.

Yves

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Should have dug a channel up and inserted a drainage channel with cheapo plastic pipe specially made for that job, gravel alone won't solve that problem, but I hope I'm wrong .

maylar said:

Excellent. We all hope you get this sorted. Then post a summary of what you learned.

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That will be a book

Bernhard said:

Should have dug a channel up and inserted a drainage channel with cheapo plastic pipe specially made for that job, gravel alone won't solve that problem, but I hope I'm wrong .

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Gravel solve the problem for two years, the watersport club don't wish to do more