The Ford Barn

DDeeD · 11-30-2019, 12:32 PM

My electric bermuda bell on my 12 volt Model A blows a 20 amp fuse almost every time I ring it. I suspect that the bell is intended for 6 volts. How should I reduce the voltage to the bell? The bell contains a solenoid. Do I need to know how much amperage goes to the coil to determine what resistor to use to reduce the (momentary) voltage? The voltage is applied to create the ding and the spring on the solenoid creates the dong when the switch is released.

redmodelt · 11-30-2019, 02:24 PM

All the suppliers should stock and sell voltage drops 12 to 6.

Synchro909 · 11-30-2019, 03:50 PM

If you only usually blow a 20 amp fuse but not always, it is obvious to me that the solenoid draws about 20 amps It takes a resistance of 0.6 of an ohm to get that (R=V/I or 0.6=12/20) meaning that on 6 volts, the current draw will be 10 amps. (0.6= 6/10)
The soleniod consumes 60 watts of power (P=VxI) P=6X10=60 watts
12 volts is twice 6 volts so the resistor will have to share 50% of the voltage and power. What you need is a resistor of 0.6 ohms and a power rating of at least 60 watts. That is, the same as the solenoid.
I don't know what the resistance and power rating is of the resistors sold by the vendors but they are made for the horns. I suspect the power ratings would be similar but you can connect a number of them in different ways to get just about whatever resistance you want at whatever power rating you want. (I have not had much success with them on a horn - maybe because of quality issues and their ratings being dodgey)

Sparky · 12-01-2019, 09:27 AM

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FYI, eBay is a good source for 100-watt power resistors. They are cheap enough that you can get a few different values and experiment. For example if you got a couple .5 ohm resistors you could hook them up in series or parallel and see what works best.

11-30-2019, 12:32 PM	#1
DDeeD Junior Member Join Date: May 2011 Location: Tipp City, OH Posts: 2	6 Volt Bermuda Bell on 12 Volt Car My electric bermuda bell on my 12 volt Model A blows a 20 amp fuse almost every time I ring it. I suspect that the bell is intended for 6 volts. How should I reduce the voltage to the bell? The bell contains a solenoid. Do I need to know how much amperage goes to the coil to determine what resistor to use to reduce the (momentary) voltage? The voltage is applied to create the ding and the spring on the solenoid creates the dong when the switch is released.

11-30-2019, 02:24 PM	#2
redmodelt Senior Member Join Date: May 2010 Location: Portland OR Posts: 6,340	Re: 6 Volt Bermuda Bell on 12 Volt Car All the suppliers should stock and sell voltage drops 12 to 6. __________________ I know the voices aren't real but damn they have some good ideas!

11-30-2019, 03:50 PM	#3
Synchro909 Senior Member Join Date: Jun 2014 Location: Melbourne, Australia Posts: 7,496	Re: 6 Volt Bermuda Bell on 12 Volt Car If you only usually blow a 20 amp fuse but not always, it is obvious to me that the solenoid draws about 20 amps It takes a resistance of 0.6 of an ohm to get that (R=V/I or 0.6=12/20) meaning that on 6 volts, the current draw will be 10 amps. (0.6= 6/10) The soleniod consumes 60 watts of power (P=VxI) P=6X10=60 watts 12 volts is twice 6 volts so the resistor will have to share 50% of the voltage and power. What you need is a resistor of 0.6 ohms and a power rating of at least 60 watts. That is, the same as the solenoid. I don't know what the resistance and power rating is of the resistors sold by the vendors but they are made for the horns. I suspect the power ratings would be similar but you can connect a number of them in different ways to get just about whatever resistance you want at whatever power rating you want. (I have not had much success with them on a horn - maybe because of quality issues and their ratings being dodgey) __________________ I'm part of the only ever generation with an analogue childhood and a digital adulthood.

12-01-2019, 09:27 AM	#4
Sparky Senior Member Join Date: May 2010 Location: Rhode Island Posts: 649	Re: 6 Volt Bermuda Bell on 12 Volt Car Sponsored Links (Register now to hide all advertisements) FYI, eBay is a good source for 100-watt power resistors. They are cheap enough that you can get a few different values and experiment. For example if you got a couple .5 ohm resistors you could hook them up in series or parallel and see what works best.