One suspects the current draw will be intermittent. SOmeone who knows more about the internals of the clock may know better, but recollection of such clocks is that they are basically a mechanical clock with an electrically powered spring winder that fires periodically to add a little bit of tension to the mainspring. (One neat thing about such a clock is that the mainspring ends up with very constant tension, and so the mechanism becomes significantly more accurate.)
You should find that the clock makes a soft thwack noise every wee while. When it does so, the clock will draw current, the rest of the time it will draw nothing. The peak current during this may actually be significant, but it will only last a fraction of a second. The average current draw will be miniscule. Probably less than the self discharge rate for the normal battery in use. But even the peak current is unlikely to be outside the capability of most wall wart power supplies. You will probably find it will happy operate over quite a wide range of input voltages.
I finally looked at astro’s excellent link. :smack:
That is a *mechanical *clock. I’ve wound that exact model a couple hundred times, and others like it thousands of times. :smack:
You wind it with the big knob. Muscle memory says clockwise winds and counterclockwise ratchets freely. Obviously that’s either correct, or off by 180 degrees; either way it’s obvious which way to make it work. They’re so-called 8-day clocks, which means a full winding ought to last just over a week. On an elderly clock I’d not wind it too close to full the first time. Just a half-dozen half-turns or so to see if it works. If not, any clocksmith should be able to clean & lube it for you.
You pull the big knob out and turn it CW or CCW to rotate the hands for setting the correct time.
So why the electrical connections? Because, like the rest of the instruments on the panel, it has internal lighting so you can read it at night. The reason there’s no spec for power draw is because it’s A) negligible, B) only used while the engine is running, and C) on a circuit with a dimmer/rheostat.
Boy, is this an awesome example of an XY problem. Sorry it took so long for us to get to the real Q and hence the real A.
I will echo wolfpup’s praise of LSLGuy’s sleuthing.
Prior to the manual winding discovery, I tried the clock’s leads on my car battery; no tic-tock, for reasons I now know (although it may have lit up and I would have never seen it on the bright day).
I just tried to manually wind the clock, and it’s apparent something in the winding mechanism is not meshing internally, although the time sets properly. If I feel brave, I may try to take it apart to see if I can re-mesh the winding mechanism.
Once again, thanks to all Dopers who gave their inputs on this.
Glad to help. No great sleuthing required. As I said, I’ve spent years using those clocks. I just had to see the picture to recognize it. I really had a D’oh moment when I did see it since I had earlier posted about your clock on the assumption it was electrical. You may not have ought to known better, but I should have. :smack: for me, not you.
By far the best feature of the 'Dope is that no matter how obscure your problem or question there’s somebody here who will pipe up with “I do/fix/answer that stuff for a living. It goes like this …” and suddenly your mystery is solved. Whatever it may be.
My recommendation: Take it to a clock shop. They can perform miracles for relatively few bucks. Unless you’re way out in the boonies there’s one not that far from you.
Good luck. Come back and tell us once it’s running. Your Dad would appreciate that.
They’re so-called 8-day clocks, which means a full winding ought to last just over a week. On an elderly clock I’d not wind it too close to full the first time. Just a half-dozen half-turns or so to see if it works. If not, any clocksmith should be able to clean & lube it for you.