VCCA Home Forums GENERAL DISCUSSION New User Forum 37 electric clock on 12V?

Hello,
i am Tino from Germany. I own a 4 door 1937 sedan. Simply a master, but with some nice goodies. Radio, electric clock, heater and 12V electric.

I have some questions about the electric clock.

The working principle ist that the magnet coil (1) pulls up the weight(2).
Due to gravity the weight pushes a gear wheel (3) and keeps the clock gear runing.
But also a little seperate mechanism (4) with electrical contacts (5).
When the contacts are closed the magnet is on and pulls up the weight again.
The contacts will be opened immediately when the weight is pulled up.
The contact is only for split second.
I tried this with a little 6V toy battery (6=plus terminal magnet coil ). When the battery ist near empty the magnet has not enough power to pull up the weight to lock into the gear wheel. So the weight falls directly down closes the contacts again an the hole system starts to shimmy.

How powerfull must a step down converter (12V->6V) be? How many amps? The magnet coil resistor is about 3Ohms.
I have only a cheap multimeter. Not good enough for messuring of amp peaking when contacts are closing.
Is a step down converter nessecary at all? Cause only a pulse is needed for the magnet and no resistors or circuits are there.
Surely i would feel better with a step down converter right now.

Thanks
Tino

Hi 37Freak and welcome to chevy chatter.

A 3 amp fuse is normally installed with the clock for protection, so that will give you some idea of the load it draws.

I don't recommend this solution, but you can operate that clock on 12-volts.

You can place a .75 ohm resistor in line that will help some.

Although the clock will work without modification, the higher voltage slams the spring loaded mechanism so hard it will eventually brake something. Damage will also be done with the resister in the circuit.

The only solution is a wire wound resistor with taps on it. You can experiment until you find a tap that produces the 6-volts at the clock. The wire wound resistor should be a maximum of 1 ohm.

I am a retired Clockmaker. I repair and restore antique car clocks. You need to install a 4 ohm resistor and nothing larger than a 2 amp fuse in the power supply to your clock. The resistor should be of the ceramic type. The resistor size of 4 ohm is not critical. It can be a little less but nothing higher than 4 ohm.