Amplifying DC Brush Motor with Encoder?

[andyew]

Dear all,

The specs of the DC Motor Circuit:
- DC Brushes
- 42 Vdc
- Armature Resistance 20 Ohm
- Inductance 17 mH
- PWM Driving Method
- Rotary Optical Encoder

My question: Could I amplify the driving output (PWM analogue output) into higher power output?

My question (2): If yes, what kind of circuit or amplifier I could use safely?

My objective: To drive slightly more powerful motor to move slightly heavier load without changing the original driving circuit/signal, but instead adding an amplifier between the NEW motor and the original circuit

Changes: additional "amplifier" circuit & slightly bigger motor

Unchange: the driver circuit, the encoder and the output signal (PWM)

This project is to hack the original device to drive slightly heavier load, but remaining the displacement and the velocity of the DC Motor Driver output (original).

Please guide or point to the resources I should read.....

Thanks alottttt!!!!!