Accessory PM DC Motor Controller
On the design block is a Permanent Magnet DC Motor Controller capable of powering motors to run
vehicle accessories such as the Air Conditioning & Power Steering. It may be in the same size enclosure as
the Isolated DC-DC Converter. To include a gas vehicle alternator as a driven accessory may seem wise
and lower cost solution, but will be much less efficient than just converting directly with a DC-DC
converter. Remember, alternators have no efficiency requirement, and are likely in the 60-70% range, not
including the belt losses and PMDC drive motor losses. This is a considerable waste of resources for a
Battery-Powered Electric Vehicle.

Depending on the demand required from the motor, it may be possible for all accessories to run from a
single Treadmill type Motor with an adjustable DC motor Controller. The goal is reliable control with low
cost. Treadmill motors are rated to 2.5HP and abundant.

This unit will have a built in L/C output filter to reduce brush arcing from high voltage battery packs
(>120V) and a pot to adjust the motor speed. Targeting 20A output capability. It will also be closed loop
voltage control to help the PM Motor maintain speed during load changes from AC system cycling, for

It will be rated around 2HP, but as always, there is still more to do so check back often!