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DC Motor DC Motor ParametersParameters

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Mark max Torque Y Axis

Mark Max RPM X Axis

X

X

Connect the points with a straight line

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X

X

Locate the Mid Point RPM

Trace a horizontal line to the Y Axis

This is the Design Torque Value

X

Mid Point RPM

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ALWAYS Record, Describe and Date the Data

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Measuring Armature Coil Resistance

The Multi-Meter selector is set to read resistance in units called ohms (). The selector is set to the lowest range (0-200 )

The Value measure is 0.9 ohms.

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Measuring Armature Coil ResistanceMeasuring Armature Coil Resistance

Set the meter to read ohms. Use the lowest range.

Short the meter leads and record the value. This is the meter error value.

Attach your meter to the two motor leads.

Slowly turn the armature shaft and record values at 45° intervals. Average these values.

Caution: Turning the armature shaft quickly, induces a current in the armature windings. This Will damage the meter.

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Calculate the Stall Current

I = ER

Ohm’s Law

The basic Algebra of electronics

E = VoltageI = Current in Amperes

R = Resistance in Ohms,

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Determining the Torque Value

ALWAYS Record, Describe and Date the Data

DF

F = Force (lbs.) 3 lbs

D = Length (ft.) .5 ft

Q = Torque (ft.lbs.)

Q = D x F

1.5 ft.lbs. = .5 ft. x 3 lbs.

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Evaluating DC Motors

Determining Robot Speed

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ALWAYS Record, Describe and Date the Data

Robot Speed EquationsUse this equation to predict the TekBot’s speed

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