How to control DC brush motor speed, torque with microcontroller?

[wmdu]

I need to control a brush motor with speed/torque by a DSP chip already on board, I understand that can be done by control voltage and current. My application is an open loop sensorless (no encoder) one for saving space and reduce cost on dental handpiece. Some body with experience on this please answer:
1) chip or component that can be linked to DSP to provide speed change, torque limit (voltage change, current limit) and forward/reverse of motor, can I controll them all in software?
2) Is there anyway to do this in real DC not PWM?

Your answer will be greatly appreciated.

 

[electricuwe]

You need two different parts for your application:

1)
A power amplifier, either linear or switched to provide voltage with positive or negative polarity to the motor

A current sensor to measure the armature current of the motor, e.g. a shunt

Depending on power rating both parts may be available in a single device or separate. Please give nominal voltage and current

2) Yes you can do it with a linear amplifier, but that is only viable for very low power. For higher power heatsinks needed for this approach will be more expensive than means to provide PWM-operation.