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Brake rheostat ohm rating


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#1 ThunderThumb

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Posted 07 July 2019 - 11:35 AM

Does the OHM rating matter a lot , I have a controller with 2.5 and a 3.0 , would a 2.0 OHM rating work , thanks


Earl Anderson




#2 Ramcatlarry

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Posted 07 July 2019 - 11:45 AM

Somewhat dependent on car/track combination.  A 2 ohm could be OK  on most commercial track uses, but would like to use 5 ohm or more for HO and homeset needs.  One or two diodes in a step switch is great also, if you are building a custom or add on brake circuit.


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#3 drrufo

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Posted 07 July 2019 - 12:20 PM

Don't worry about adding resistors. You are using the ohmite potentiometer on a Choke Master,  just make sure the wire wrap is clean. I use the ohmite in the range from 2 to 3 ohms. The ohmite might have a 2.04 ohm rating, read the side of the potentiometer for the rated value.

The ohmite comes in the smaller ohm rating, wire wound pots usually come in 5 ohms. That is what I use for everythnng but the HO. The HO gets a 100 ohm pot because the resistor array has a higher value in the HO controller.

 

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#4 ThunderThumb

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Posted 07 July 2019 - 12:26 PM

Thanks a lot fo rthe info John and Larry


Earl Anderson

#5 Jim Difalco

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Posted 11 July 2019 - 06:44 AM

Earl, the real answer is how much brakes do you take out of the car when running. If you only take a little bit of brakes out then the 2 ohm will be fine. It will actually spread out the range and give you finer adjustment with the 2 ohm rheostat. If you have a 3 ohm now but regularly turn the brakes down most of the way then you will not be able to reach the same brake level on a 2 ohm.

 

I used 2 ohm rheostats then switched to a 3 ohm the last 20 years.

 

25 ohm value for 1/32 and 100 ohm for H.O.

 

Diode braking is awful. I guarantee that on the same track you will find a lane where position 3 will be too much brakes and position 4 will not be enough.


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#6 ThunderThumb

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Posted 14 July 2019 - 11:36 PM

Im running all wing cars OMB , G27 and G7 so braking is not a big deal , I noticed some controllers havea 2 OHM and a 3 OHM and I think one had a 2.5 OHM , thanks for the info Jim
Earl Anderson

#7 Mr. M

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Posted 15 July 2019 - 06:52 PM

Why is diode braking so bad?
Chris McCarty

#8 Jim Difalco

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Posted 16 July 2019 - 10:47 AM

When you compare a typical pro brake with about 30 positions and an economy brake that has 100 positions with a diode brake that has 6 positions, which would you want? The difference is substantial between diode settings so you do not have the fine tuning available for braking.


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Jim Difalco
Difalco Design
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