electronic clock - UK Vintage Radio Repair and Restoration Discussion Forum

Breton56 · 19th Sep 2012, 4:50 pm

I have a small electronic clock for repair. The mechanism is contained in a clear moulded plastic case on the backplate of which the words "Electronic Western Germany DBP ang.1548013" are moulded.

When received the balance spindle was out of its bearings. Having re-fitted the spindle the clock does not work. The electronic module contains an integrated cct marked 730, 760 or 780, not ,which a 100k resistor and two tants 15 and 2.2 mic and a tapped coil which sits between two magnets on rings on the balance spindle. Western Germany suggests manufacture before re-unification. Does anyone know anything about these units and what might be the problem?

julie_m · 19th Sep 2012, 5:07 pm

Tantalum capacitors are "change on sight" components.

If replacing the caps doesn't effect a cure, and the coil is sound, you'll have to manually operate the clock mechanism for a while to work out how many pulses it takes to move it on one hour; then you can build a new electronic module, using an 8-pin micro with a crystal oscillator.

Nickthedentist · 19th Sep 2012, 7:28 pm

Note that many early plastic movements are pretty much worn-out now, so do check that all the mechanics are fine before wasting time/money on getting the electronics going.

Is it like any of these? http://www.clock-museum.co.uk/20c/i~mvmnts.htm

Nick.

Breton56 · 21st Sep 2012, 9:08 pm

Thanks for the replies so far. If I can find the required tants I will try replacing them. In this rural area of France there is nothing like Maplins but I have to make a visit to the UK in the next week or so.

The mechanism is identical to the eurastyle unit shown in the clock museum link but with a transparent case and a virtually identically shaped PCB with one 100k resistor, two tants and an IC of about 0.2 inch diameter.

emeritus · 21st Sep 2012, 10:51 pm

(West) German Patent DE 1548013 was filed and granted to a private Swiss national. The manufacturer presumably bought the patent or manufactured under licence. The German Patent Office web site indicates that there are no equivalent patents in other countries, so no English equivalent. From a quick skim, the patent does gives a description of the principles of operation in general terms, but no details of the electronic circuitry. The invention is mainly concerned with the magnet construction, which is a laminate of oppositely-poled laminar magnets.

julie_m · 22nd Sep 2012, 9:27 am

Modern electrolytics are smaller than older ones of the same rating, so you probably won't need to use tantalum ones.

Breton56 · 10th Nov 2012, 6:50 pm

Original mechanism now replaced (by a clock and watch repairing friend) with a quartz movement. Original mechanism retained for a possible second look sometime.

19th Sep 2012, 4:50 pm	#1
Breton56 Triode Join Date: Jul 2011 Location: Mumby,Lincolnshire Posts: 45	electronic clock I have a small electronic clock for repair. The mechanism is contained in a clear moulded plastic case on the backplate of which the words "Electronic Western Germany DBP ang.1548013" are moulded. When received the balance spindle was out of its bearings. Having re-fitted the spindle the clock does not work. The electronic module contains an integrated cct marked 730, 760 or 780, not ,which a 100k resistor and two tants 15 and 2.2 mic and a tapped coil which sits between two magnets on rings on the balance spindle. Western Germany suggests manufacture before re-unification. Does anyone know anything about these units and what might be the problem?

19th Sep 2012, 5:07 pm	#2
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: electronic clock Tantalum capacitors are "change on sight" components. If replacing the caps doesn't effect a cure, and the coil is sound, you'll have to manually operate the clock mechanism for a while to work out how many pulses it takes to move it on one hour; then you can build a new electronic module, using an 8-pin micro with a crystal oscillator. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

19th Sep 2012, 7:28 pm	#3
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,853	Re: electronic clock Note that many early plastic movements are pretty much worn-out now, so do check that all the mechanics are fine before wasting time/money on getting the electronics going. Is it like any of these? http://www.clock-museum.co.uk/20c/i~mvmnts.htm Nick.

21st Sep 2012, 9:08 pm	#4
Breton56 Triode Join Date: Jul 2011 Location: Mumby,Lincolnshire Posts: 45	Re: electronic clock Thanks for the replies so far. If I can find the required tants I will try replacing them. In this rural area of France there is nothing like Maplins but I have to make a visit to the UK in the next week or so. The mechanism is identical to the eurastyle unit shown in the clock museum link but with a transparent case and a virtually identically shaped PCB with one 100k resistor, two tants and an IC of about 0.2 inch diameter.

21st Sep 2012, 10:51 pm	#5
emeritus Dekatron Join Date: Jan 2012 Location: Brentwood, Essex, UK. Posts: 5,345	Re: electronic clock (West) German Patent DE 1548013 was filed and granted to a private Swiss national. The manufacturer presumably bought the patent or manufactured under licence. The German Patent Office web site indicates that there are no equivalent patents in other countries, so no English equivalent. From a quick skim, the patent does gives a description of the principles of operation in general terms, but no details of the electronic circuitry. The invention is mainly concerned with the magnet construction, which is a laminate of oppositely-poled laminar magnets.

22nd Sep 2012, 9:27 am	#6
julie_m Dekatron Join Date: May 2008 Location: Derby, UK. Posts: 7,735	Re: electronic clock Modern electrolytics are smaller than older ones of the same rating, so you probably won't need to use tantalum ones. __________________ If I have seen further than others, it is because I was standing on a pile of failed experiments.

10th Nov 2012, 6:50 pm	#7
Breton56 Triode Join Date: Jul 2011 Location: Mumby,Lincolnshire Posts: 45	Re: electronic clock Original mechanism now replaced (by a clock and watch repairing friend) with a quartz movement. Original mechanism retained for a possible second look sometime.