Re: ?low temp issue

John Hubert

This is actually the second time this question has been raised with me inside 24 hours (the other being locally) and so I think I will try and put together a short ‘guide’.  

Firstly, if you have a copy of “Synchronome, Masters of Electrical Timekeeping” by RHA Miles - this is fully covered in detail in Chapter 13.  Can I recommend you get a copy of this ’standard reference book’ which is available from the AHS, here  There is full detail and illustrations there.

Secondly, I will try and follow up with a short summary of the key points, but to get all correct - there is a ‘method’ to follow, rather than just experimenting.  I have to add that I have one slave dial that is definitely temperature sensitive and I have never quite managed to fully ’tame’ - the possible reason being that the coil may have lost some layers in the course of its history (it is over 100 years old).

I will try and put something together.


On 16 Jun 2020, at 23:35, James <wikitoria4501@...> wrote:

Hi all,

Am having some problems with three slave dials.  The circuit consists of a Master with 10 slaves (dials) operating at 13.81 volts, 0.33 amps and 41.4 ohms.  It is powered from a lead acid battery via a buck converter to regulate the voltage.  Five or six times a year, some of the slaves will drop 5 or so minutes overnight.  It is always the same dials and it very much seems to occur only on colder nights in winter when the temp in the house drops.

Is this a mechanical or electrical problem?     

If it is a electrical problem should the voltage be increased slightly in winter?  Or do the slave dials require some adjustments?  If so, what adjustments should be tried first?

Many thanks for your thoughts...

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