Current draw self winding clocks

Walt-LA
Walt-LA Senior Contributor
edited November -1 in HUDSON
Anyone know the current draw on the self winding clocks Hudson used in

'51? Clocks were fused at 3 Amps.



Tried a !.5 Ohm resistor which should drop 12 V to 6V at a 4 amp pull, and scorched the points. Would 2 Amps be enough ? (can put two Echlin VT 6187 resistors in series to get that. Perhaps another reason to stay with 6 V.... Walt-LA

Comments

  • Geoff
    Geoff Senior Contributor
    Walt, I have no idea of the current draw, but what you could do is disconnect the battery and let the colck run down, at which stage the points will be closed, and you can measure the resistance of the coil with a digital ohm-meter and calculate the amperage using ohms law. Otherwise it is a matter of experimentation with various rating resistors until you find the correct value.

    Geoff.
  • Park_W
    Park_W Senior Contributor
    Walt, my doing what Geoff suggested yielded a figure of 12A. But since it draws that current for such a short time during the wind cycle, it won't pop a regular type fuse or a circuit breaker even if they're rated quite a bit lower. I'm using a 1/2 ohm, 25W resistor, and it's worked fine so far, about three years. I spoke to a clock repair guy when I was doing my 12v conversion, and he thought it wouldn't affect the longevity of a typical automotive clock of this type if you just went ahead and ran it on 12v without a resistor. I decided to hedge that view a little with the half ohm resistor.
  • Geoff
    Geoff Senior Contributor
    LIke I said, you could probably measure the time the points were closed, and the solenoid energised, in a few milliseconds, and as mentioned, the impedance of the coil comes into account as well. There must be a bit of tolerance in these coils, as I have a 12 volt clock in my Jet, which is still on 6 volts. Only difference seems to be that the time between energising is about 45 seconds, against 1-1/2 minutes for the clock in the Hornet. The other solenoid on the Hornet, on the overdrive, draws a whopping 15 amps on pull-in, until the pawl engages, and the relay points open. Now that's some serious current!

    Geoff.
  • Walt-LA
    Walt-LA Senior Contributor
    Thanks all! Seems the clocks will run on quite varied power sources - including 6 V lantern batteries (dry cells). But as so many are successfully running their clocks on 12V, will give that it a try. Certainly simpler. Again, THANKS. Walt-LA
This discussion has been closed.

Categories

In this Discussion