Janzen Electronics.  http://individual.utoronto.ca/janzen/electronics

Force Generator

Many school science classes put high-tech equipment to use. These devices often measure a quantity, but there are few machines that actually produce the accurate quantity. This force generator produces an accurate force in a certain direction, regardless of whether the object in question is moving.

A string, which the experimenter attaches to an object, is pulled on the other end with a certain force by the force generator. The string's force and displacement are monitored by sensors in the generator, and this data is streamed into a computer. The computer software constantly adjusts the motor power. This process permits an accurate force to be monitored and maintained, even when there are unpredictable outside influences. The force and distance data conveniently give the software the power to calculate or control velocity, acceleration, work, and kinetic energy. The object's mass is automatically calculated.

The number of applications is great. A basic experiment is to accelerate a cart across a smooth surface. Rather than using the push of a human hand, which lacks accuracy, the force generator will produce a controllable, timeable, and accurate force.

The controlling software contains many different functions. Feel free to peek at the manual below and see what can be done.

Force Generator system: