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Eureka Eureka Clock Governor circuit

James McDermaid

Registered User
Apr 29, 2011
137
8
18
I acquired a Eureka clock which I plan to service as soon as the new wears off. It is a "four glass" model.

It is running fast and on 3 volts. I haven't tried it on a lower voltage but will soon. I'm aware they were made to run on 1.5 volts from an old #6 dry cell (no longer made).

Does any of the group happen to have a simple circuit for a governor or an efficient voltage regulator?

I believe at one time someone made a device which pulsed the supply voltage at either 1.3333 or 2.6666 seconds which would tend to synchronize the clock.

It may be that a good cleaning of the balance bearings and the clock would run on 1.5 volts and keep some kind of decent time.

I hear mixed reports on how well these clocke actually kept time but now I want to find out for my self.

The contact flag and pin look to be perfect.

Jim
 

Tinker Dwight

Registered User
Oct 11, 2010
13,666
72
0
Calif. USA
I'm not sure the voltage has that much effect on the
speed unless it is grabbing two teeth on some of the
swings or something is limiting the swing.
Tinker Dwight
 

James McDermaid

Registered User
Apr 29, 2011
137
8
18
I haven't seen it grab two teeth. It is supposed to run on 1.5 volts and I have 3 volts now. It was running on 3 when I got it recently and I haven't played with it yet.

I'm led to believe that if it keeps time on 1.5 it will run fast on 2.5.

I don't know how accurate Eureka clock actually are, some say not and some say as good as an american pendulum.

First Eureka I have ever seen so I'm learning.

Jim

Jim
 

praezis

Registered User
Feb 11, 2008
497
38
28
Germany
Country
Region
Mr. Mumford offered a voltage regulator for Eureka and has more info on his website.

You can also make one DIY eg. with LP2951 or discrete with a few transistors.

Frank
 

James McDermaid

Registered User
Apr 29, 2011
137
8
18
Mr Mumford no longer sells his synchronizer.

The Eureka has an odd beat and Mumford used a microprocessor to compute the interval.

I bought a regulated battery from Carlton Clocks in the UK. It is a replica of a No 6 dry cell that was made by Pete Smith (Horligix). Sorry if I misspelled. It is adjustable from low to about 3 volts and uses 4 "C" cells. I'm going for the original 1.5 volt operation.

I added an old Eveready label so the battery which looks more original.

The Eureka has been running quite consistent since I adjusted the Balance Spring length.

It has a pair of double "AA"'s that are down to about 2 volts. Been running it for the past three months.

It gets a rebuild soon as it needs cleaning and one glass bearing cap replaced.

Carlton Clocks in the UK has the bearing glass parts.

Jim