The following photograph shows an adjustment of the cycle frequency (tensile) using a trim potentiometer on the On/Off Power Cycler.  The trim potentiometer to the left allows for an adjustment of the electromagnet duty cycle (% of cycle that the electromagnet is powered).

  The rotary optical encoder disk and sensor.

Above:  The connection between the rotary optical encoder and the data acquisition card.

Above:  Adjusting the distance between the steel plate and the electromagnet.

Adjusting the vertical load.