# Citizen Transistor Clock --Need help



## ranatungawk (Feb 6, 2018)

Hi friend needs an advice on this:

This Citizen Transistor wall clock works great! But sometimes it run little fast or slow. I found its circuit as below








In another forum I found the following solution: adding a diode and resister as I mentioned in the diagram to minimize the reverse voltage pulse when the transistor turns off.
This is not a crystal oscillator clock , This is a transistorize clock ! even though it's simple, its working very well since 30Years!...here what i need to know electronically is : whether this modification is correct ! make any seance theoretically. further, does it make any reverse voltage pulse as it say , and how it effect ?


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## John MS (Mar 17, 2006)

Below is some information about a similar Citizen movement. It uses an electric balance wheel that would have been reasonably accurate in it's time, but not as accurate as say a mains powered electric clock. But better than a spring powered balance wheel clock of the same vintage. A little gain or loss in an electro mechanical clock movement does not surprise me. I would not make that modification unless you understand what it is supposed to fix.

HOROLOGY CRAZY: Citizen Transistor Clock


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## ranatungawk (Feb 6, 2018)

Thanks for the information ! This is a transistorize clock ! even though it's simple, its working very well since 30Years!...here what i need to know electronically is : whether this modification is correct ! make any seance theoretically. further, does it make any reverse voltage pulse as it say , and how it effect ?


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## John MS (Mar 17, 2006)

I do not know the answer to those questions. Have you asked the person who wrote modification?

I can think of two possible sources of problems for that type movement.
1. Is the correct battery being used? 
2. Mechanical wear and dried lubricants in the moving components.


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## Bagpuss007 (Feb 23, 2016)

I would think it gets all its timing from the balance wheel, as it works as a kind of free balance it should be reasonably accurate I would have thought. Also I notice it has an hairspring with a regulator, so you should be able to regulate like any normal balance wheel escapement.


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