In the old DC layout days I used a 25-Ohm / 3 watt rheostat and DPDT-center-off toggle switch to run trains with a homemade tethered throttle. I would think it would work for a turntable too.
http://www.hollandcomputers.com/store/pc/25-Ohm-3-Watt-Rheostat-5-Tolerance-Wirewound-Variable-Resistor-Potentiometer-p5991.htm
I don't think we are talking about a large sum of money here, so I would really like to get both a pot and a resistor. Try them both see which works best. The specs for the pot would be............ ? Thank you, you have been most helpful.
How about we back up a little bit. Since the decimal point on my meter doesn't move lets say the amps are a little less 0.5 amps.. Are you suggesting I use a one watt resistor instead of a potentiometer?
Of a total of 12 volts the table moves at the right speed 3.6 volts 45 to 46 ma.. I am reading whats shown on the meter. I guess I could take a photograph if you like.
So at 3.6 volts the amps are 45 to 46ma.
I doubt a pot will work as they do not handle much current by them selves. Most Pots are rated at two watts from what I recall. Do the math.
They ususlly are used with a power transistor and you need a switch for reverse which I am sure you know. Years ago I made my own DC power packs with a 10k pot, low power npn transistor, and 2N3055 power transistor.
Connect your multimeter with a power pack and TT and turn up the pack and watch the meter. Easy enough to do. Every model railroader should have a meter.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Yes, I suppose I should be talking about a potentmeter, anyway the motor is 24ohms just sitting dead and works with no more than 12 volts.
Are you looking for a rheostat or potentiometer? Those are two different animals.
I suspect the motor will be in the 500 ma range. We never did measure the current. If you have a power pack, measure the current first, then buy a rheosat. I have not bought a rheostat in years. They are tough to find. potentiometers are not high current. Our club had one of those TT's but we used an old power pack. We saw no reason to go any other way.
Yes I aggree old DC power pack will work, however I have built a control board for the roundhouse, and turntable useing hard board, and have left space for this rheostat so it all looks good and uniform. So I still need the specs for this rheostat. Thank you for any help you may offer.
banjobenne1 Hello I have an old (non digital) Walthers turntable, what type of rheostat do I need to control the speed?
Hello I have an old (non digital) Walthers turntable, what type of rheostat do I need to control the speed?
You don't want a rheostat. A regular old DC power pack will work just fine.
That is what I use to use.