If you have an H-Bridge drive circuit for a motor, you may need a way to monitor the load on the circuit. This circuit is nice because it provides a single output that could be monitored with a microcontroller or other device.
The trick is to use current sense amplifiers and measure the current on each leg of the circuit. The LTC6103 is a good choice because it has two sense amplifiers in the same package.
Here is a circuit diagram that will allow you to monitor the load.
For moe detail: Monitor your H-Bridge Circuit Load