The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: Triton Thrasher on 02.01. 2018 14:10

Title: Alton cycles/rev
Post by: Triton Thrasher on 02.01. 2018 14:10
Anyone happen to know how many AC pulses are produced by one complete turn of the drive pinion on a single phase Alton with the step-down geared drive?

I’m having to use the AC as an electronic rev counter signal.

And it’s not leaking oil at the moment, so I’m reluctant to disturb the thing.
Title: Re: Alton cycles/rev
Post by: Triton Thrasher on 02.01. 2018 15:08
Realised it’s something of a minority interest so took it off anyway.

The answer appears to be 24.

Edit: after trying it out, the answer appears to be 12, so far as the rev counter is concerned.
Title: Re: Alton cycles/rev
Post by: mikeb on 03.01. 2018 05:48
TT i thought you had one of those ebay HT sensing tachos - did that not work out? (i was thinking of one for my b33)
Title: Re: Alton cycles/rev
Post by: Triton Thrasher on 03.01. 2018 10:17
Yes I still have this “matchbox” and it’s working fine.  Have to say it’s working more consistently with the recently fitted Wassell electronic ignition than it was with the magneto. But then the magneto was sneakily becoming faulty.
(https://i.imgur.com/ZDcfn25.jpg)

Now I’m trying for the “twin clock look,” with big round GPS speedo and this tacho.

(https://i.imgur.com/Oknu7Af_d.jpg)

Speedo
(https://i.imgur.com/L0yIFlt_d.jpg)

They’re both 85 mm, so a bit bigger than old Smiths 3”.
Title: Re: Alton cycles/rev
Post by: Greybeard on 03.01. 2018 10:23
Just curious; how come those pictures don't enlarge when clicked/tapped and how come they don't have a file name?
Title: Re: Alton cycles/rev
Post by: Triton Thrasher on 03.01. 2018 10:42
Just curious; how come those pictures don't enlarge when clicked/tapped and how come they don't have a file name?

Shared from Imgur.  I don’t know the reasons.

Link to rev counter on EBay: 
https://m.ebay.co.uk/sch/i.html?_from=R40&_trksid=m4084.l1313&_nkw=131948306435 (https://m.ebay.co.uk/sch/i.html?_from=R40&_trksid=m4084.l1313&_nkw=131948306435)
Title: Re: Alton cycles/rev
Post by: duTch on 03.01. 2018 12:09
 
Quote
..... The answer appears to be 24.
       
    *conf2*       
 or 42 ??
Quote
TT i thought you had one of those ebay HT sensing tachos

I ordered a couple of those but they never arrived, but I did at least get a refund  *woo*

 
Quote
Just curious; how come those pictures don't enlarge when clicked/tapped and how come they don't have a file name?

 I find that happens a lot, even with various file types; been meaning to ask but seems too complex, *pull hair out* 

  oh yeah ** can't help with the Alton


Title: Re: Alton cycles/rev
Post by: Triton Thrasher on 03.01. 2018 12:22
I should also apologise for not using Smiths Chronometrics!
Title: Re: Alton cycles/rev
Post by: duTch on 03.01. 2018 13:06

 
Quote
I should also apologise for not using Smiths Chronometrics!

  *????*

 why *conf2*.....I'm not rivet counting *smile*, and if anyone is ....ahem
Title: Re: Alton cycles/rev
Post by: Triton Thrasher on 03.01. 2018 17:24
Bodge of the day.