AMS DCB-274 manual Wire Motor

ADVANCED MICRO SYSTEMS, INC. ADDENDUM

1B
1A
2A	2B
6 Wire Motor

C: Adapting Available 6 Wire Motors

A 6-wire motor is equivalent to the 4-wire series motor.

In practice the two coil ends are connected, while no connection is made to the center tap.

Half Copper or 50% Winding

The maximum speed can be increased by using ½ the coil. To do this, connect the driver between the center tap and one end of the winding.

The tradeoff is a loss of torque. The RMS current is the manufacturer’s unipolar amperage rating with the same wattage per phase.

Often a 6-wire design is being upgraded or the size, features, availability or cost dictate the 6-wire motor. Some characteristics can make the motor impossible to use. Many motors are rated at voltages in excess of 5 volts. This means that 10 volts is necessary in the series (100% copper) configuration.

PIN 1

PIN 2

PIN 4 PIN 5

6 Wire, Half Copper

Aside from having excessive inductance, proper chopper operation dictates operation from voltage sources much higher than the motor rating. The minimum recommended value for VMM (DC supply) is 2 times the winding rating (the higher the better, until excessive heating occurs or insulation breakdown).

The Empirical Method for Fine Tuning Your System

The “empirical” method is the best approach for “fine-tuning” the system and can/should be used for all AMS products. When the best values are determined they can be used in future production, providing tolerances are sufficiently close.

In this sequence index commands must be executed at the actual “worst case” operating speeds and conditions.

1.Gradually reduce the current until operation becomes erratic or undesirable.

2.Increase the current gradually until reliable operation is obtained. Then increase the current equally by 10 to 20%.

In any of these adjustments, monitor motor temperature and insure that excessive heating does not occur. Larger motors require more time for temperature to stabilize. When a low hold current and short run cycle is used, heating effects are reduced.

*Optimum amperage is the lowest current where the application indexing is reliable. Sometimes higher currents (still below the motor ratings) will decrease reliability.

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