Hello all, I understand just enough about electronics to make some pretty simple mistakes, so I'd like some quick input on a project before I purchase some resistors.
Basis:
My brother-in-law's water softener stopped working. The valve actuation motor-a 24V motor as far as I can tell-is fried. The casing became corroded and rusted solid when the house sat for a year without use before they bought it. The motor is a MOLON motor in a gear housing that costs $60 to replace. I found an IDENTICAL motor in all respects including mounting holes at Radio Shack except for the voltage rating is 9-18V vs the 24 supplied by the water softener. So, I did a lot of reading and even got a Circuit testing app to try to understand what I am attempting to tackle in converting the 24V down to 12V to run this motor.
My research:
I've learned that by creating a voltage divider with two identical resistors I can tap off half the voltage for the motor. My trouble is in choosing the wattage rating and proper value resistor to dissipate some of the voltage. The way I calculate it, two 20 ohm, 20 watt resistors will do the trick, but I'm not 100% certain and don't want to mail order them if they won't work. I made the mistake of putting two 1/4 Watt 20 ohm resistors together across a 12 volt gel-cell battery that I'm using for testing and blowing one of them out. My understanding of the voltage/current/supplied amperage vs drawn amperage relationship has a few holes but I'm really trying to learn through this. If anyone can offer some advice or assistance I would be appreciative.
Motor: 9-18VDC motor from radio shack rated at 1.98A max
Water softener supply voltage 24V, current unknown because it gives an error and won't function without the motor--and I can't run the new motor without knowing how to step the voltage down!
Thanks in advance,
Jim
Basis:
My brother-in-law's water softener stopped working. The valve actuation motor-a 24V motor as far as I can tell-is fried. The casing became corroded and rusted solid when the house sat for a year without use before they bought it. The motor is a MOLON motor in a gear housing that costs $60 to replace. I found an IDENTICAL motor in all respects including mounting holes at Radio Shack except for the voltage rating is 9-18V vs the 24 supplied by the water softener. So, I did a lot of reading and even got a Circuit testing app to try to understand what I am attempting to tackle in converting the 24V down to 12V to run this motor.
My research:
I've learned that by creating a voltage divider with two identical resistors I can tap off half the voltage for the motor. My trouble is in choosing the wattage rating and proper value resistor to dissipate some of the voltage. The way I calculate it, two 20 ohm, 20 watt resistors will do the trick, but I'm not 100% certain and don't want to mail order them if they won't work. I made the mistake of putting two 1/4 Watt 20 ohm resistors together across a 12 volt gel-cell battery that I'm using for testing and blowing one of them out. My understanding of the voltage/current/supplied amperage vs drawn amperage relationship has a few holes but I'm really trying to learn through this. If anyone can offer some advice or assistance I would be appreciative.
Motor: 9-18VDC motor from radio shack rated at 1.98A max
Water softener supply voltage 24V, current unknown because it gives an error and won't function without the motor--and I can't run the new motor without knowing how to step the voltage down!
Thanks in advance,
Jim