I have a kndo electric clock that I need help with. Can anyone tell me the voltage needed and if a circuit board is needed? If a circuit board is needed dos anyone have a diagram or picture
SL, the voltage would be 1.5 volts, as in a single "C" cell. I believe the electronics is in the armature.
SL What is the actual problem, and do you have access to a meter? I don't think your circuit board is missing - they were not made with one, AFAIK. There have been quite a few threads on these - do a search. I think the actual circuit is inside the pendulum bob and consists of two coils (drive and sensing) and a switching transistor, together with a few passive components.
I am not aware of any books that specifically address the difficulties associated with the KundO transistor switched clock. The KundO clock and similar were developed by ATO and based on work by Lavet and Hatot; a logical adaptation of the transistor switch applied to the earlier ATO "weak current dry contact switched clocks. There are books that explain the principle in a few paragraphs but do not address what to do when they quit. You will find a pleathora of specifics about the KundO and similar on this section of this NAWCC message board using the SEARCH facility. Take a look. Search using the word kundo and specify in Early Electric Clocks an dWatches, 1840 to Present else you will be looking at a whole lot of fixes for 400 day and torsion pendulum clocks made by KundO.
Hi Friends I fortunatly have the original repareinstructions for Kund electronics with the exact datas for current flow,resistance of the coil as well as advice where to oil and where not. If You send me an email I try to get the info to You. ingeborg_rasch@web.de Greetings from germany Burkhard
Burkhard That sounds like what a lot of people are waiting for! Can it be posted on the forum? Well done.
Thank you very kindly Rasch for the six pages of KundO technical documents for the transistor switched pendulum clocks. The diagrams, sketches and lists although in German language, are self-explaining in any language. A language dictionary helps. We are indebted to you for making the documents available to us. Again, thank you Rasch.
I realize this is a very old thread, but as a new Kundo electronic clock owner I wanted to thank Rasch for furnishing the invaluable technical information. My clock is working fine now, but I'll file this away for future use. Thanks again! Rt
I only just found this information after it was posted almost 3 years ago. I am asking someone now to help in translating it for me. Thanks Burkhard for this information.
My friend tried to help me translate the German language on the technical sheets and he was not able to. He has only the basics of the language. I was wondering if someone here could translate these pages and they be put into the archives of the NAWCC.
Hello, Id like to make a contribution to the KUNDO discussion. I'll attach 2 pages of instructions by the Kundo company which I took from the 'VDU Elektrouhrenmappe' - Sorry - but it's in German. Maybe there is some bilingual member. There has been an article on 'How to repair a Kundo clock' in the Horrological Journal July 1998 - I have a poor copy in case somebody is interested in that.
For everybody's use: Here is a translation of the repair instructions. The translation is a little bit rough, there were some unusul terms (for me) that had been used. Uhralt
This site is amazing! One question, and one pointer to further information about these clocks. Question: How many seconds/day is each "notch" on the rotating adjusting weight? For further information about the electronics (a one-transistor amplifier): Kundo Electronic Repair Mr. Elliott has written-up his experience re-winding the coils and re-building the one-transistor circuit of the Kundo clock. Charles Cohen Edit 18/4/26: I replaced the non-working link with the present website address. John Hubby
Hi Charles,I dot think that there is a kind of "apriory" relation between the markings on the pendulum weight and a definite number of seconds per day advancing or slowing.AFAIK these markings serve as a rough orientation of the amount the weight is turned the one or other direction in the proces of regulating the clock mainly by try and error.Can be wrong though(?) Burkhard -> posts merged by system <- Kevin,do You have a special question or are You asking for a more general purpose?Special question could be answered/translated right away;if requested I´d undertake the labor of translating side after side over the next months,allthough I have to admit that I don´t understand nothing about electricity and related subjects(I´m purely mechanic,You know?)so I´m not sure to get everything right.Do You have experiance with translation-programs?What do You think? Burkhard
Hi Burkhard, i think i am ok on the information provided. I will print it out for reference. I have two Ato clocks now that dont work.I know of one person who lives near me who might be able to repair them or make one working clock out of the two.If not i may just put both on Ebay and sell for parts. Thanks again Burkhard for your help.
Hope I´m allowed to revive that old threat:What has hapened to the attachments of this thread,I cannot read them anymore.Is it possible for the moderators or administrators either to "switch" the pics on or to translate them into a format that can be read?Even I have lost acces to the original papers :bang: TIA Burkhard
Hi In one of the diagrams they show testing the battery with a milliameter across the leads. Do not do this with an alkaline C battery. It will most likely damage the movement ( or on a good digital blow a fuse ). It will often cause outgassing in the cell that will cause it to fail in a short amount of time. Tinker Dwight
In my eyes, I don't see the caution in Tinker Dwight's missive. The sketches clearly reveal measuring battery voltage using a VOLT meter and showing the MiLLIAMPERE measurement using the instrument in CURRENT mode. The graphic instructions are correct as far as I can see in browsing the sketches. If there is a mistake, it is on account of the evolution of the milliammeter. Most in practical use are too well dampened to show accurately, the tiny anticipated 2 milliampere current. It comes and goes with the motion of the pendulum far faster than most d'arsonvil meters can respond. The principle of the KundO circuit uses the induction a small current to switch the circuit. The faster the pendulum moves, the larger the switching current. The opposite is true. With the pendulum magnet in slow motion, there will not be enough current induced to switch the transistor, hence no battery-drive coil current and no measurement using an "in-circuit" current measurement. Digital multimeters are far too slow to show the current unless the instrument has a "peak" reading mode. Anyone else find anything to argue about?
Les, I suppose it would help to know which diagram Dwight is refering to, and whether the test is for battery voltage (which is all I ever test for to determine if a battery is OK or not). Never had any problems using a multimeter to check batteries. On the rectangular 9 volt batteries, I have been known to do a tongue test, which is a pretty good indication of whether there's much left or not (if you feel a tingle, the battery is likely good). Of course the meter is much better than your tongue for this job.
Harold,You´re right.It´s a problem with my computer.On another computer I can read them.Thank You! Burkhard
Hi Harold and Les My mistake. I was looking at the picture on a small screen. It looked like the mA meter was being placed across the battery. I couldn't figure what they intended but thought the battery had an internal limiting resistor. Tinker Dwight
A really simple function test for the KundO battery clock requires only an earphone. No volt or ammeter. Simply connect an earphone or pair of "ear-buds" in the circuit and set the pendulum in motion. If the transistor circuit is functional, a squeal or whistle sound can be heard at each stroke of the pendulum solenoid. In practice, I used a small piece of two-sided printed circuit board material with attached wires inserted between the dry cell and the dry cell holder contact. A snapshot of the test is as below.
Curious, I reproduced Les' set-up. My Sony headset has 2x 27 Ohms which I connected in series and connected it between cell (+) and my Ato clock. The sound of the current pulse is clearly audible but not very loud. I picked it up with my soundcard (signal not yet clipping). The MIC input is AC coupled and leaves only the slopes of the original rectangled pulse. I also registered it on the scope of my watch tester software. Enjoy, Frank
Tinker Dwight suggests that the earphones I used were high-impedance magnetic. Yes, they were electromagnetic, not piezo-electric. They were simply branded "American Airlines" and have a significant DC resistance of about 60 ohms. This, I believe to be a significant series impedance which put the KundO's transistor-solenoid circuit into audio frequency oscillation at each stroke of the pendulum magnet resulting in an oscillating audible sound in the earphones which was interrupted at the critical points in the pendulum magnet motion. In retrospect, I should have repeated the experiment using a non-functional KundO battery clock. I'm thinking it would be a good idea to continue this electronics discussion off-line using PM as we are straying away from horological discussion. Some excellent reference stuff has been brought to the foreground. We owe big thanks to dietrich and to Uhralt for the excellent and useful KundO reference material and drawings. Kudos guys.
Thanks for bumping this back to the top. I've been looking for those diagrams for a while. I notice there is a compensating weight shown in the bore for the magnet in the pendulum. I have not found this in practice, but I guess it would remedy my fast runners. I don't recall that much space left once the magnet is in place. I'll check again. Lead? Eric
I sell Brand new circuit boards on e bay to anyone needing new circuit board for electro magnetic clocks. Price is 55.00 plus shipping Inquire here : Jerri2222@ aol.com
I have the same problem of not functioning and I suppose that the transitor is faulty. My Problem is : how can I open the case of magnet? Thanks FerBo
