KB578: Using MRC RailPower 1370 with Zephyr Xtra Jump Ports

This article was last updated on Aug. 10, 2011, 3:24 p.m. | Print Article | Leave Feedback

Q:  I have an MRC RailPower 1370 DC power pack.  I was wondering if that would work as a jump throttle on my Zephyr till I get my UT4 LocoNet Throttle?

A:  We think that the answer is "No", but you will need to verify whether this power pack produces pure or pulsed DC power directly with MRC.

Throttles used with Zephyr Xtra via the Jump Port must produce pure DC power, often referred to as "smooth" power packs.

Many "advanced" analog power packs use automatic pulse injection to make model locomotives run better at slow speeds.

This uses 1/2 wave AC power that makes the locomotive's motor vibrate slightly at very low speeds.

This is done because of the DC motor's tendency to "cog" or lock up as the motor windings turn inside the magnetic field of the motor.

As the motor speed rises, this 1/2 wave power is lessened until the locomotive is operating at a higher speed.

As of the time this article was written, it is not clear from the MRC website if the 1370 has this feature, but the language of their description would indicate that this is probably so: "Enjoy advanced electronic circuitry at an exceptional price...". Check with MRC to determine if this pack supplies pure DC or not.

Some analog packs have an on/off switch for this feature, but the MRC 1370 does not appear to have this switch.

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