| 摘要 |
PURPOSE:To enable a control of contact pressure with high accuracy to be effected assuredly by constituting a position control circuit such that the contact pressure control is effected with taking into consideration, in addition to the amount of displacement due to contact of a movable member with a stationary member, the rate of change of such displacement amount. CONSTITUTION:A sampling hold circuit 2 receives and samples a signal Vi of the position of a movable member 2 to hold same, and a subtractor circuit 3 calculates the difference of the position signal Vi from the output of the sampling hold circuit 2. Integrator circuits 4, 5 integrate the output of the subtractor circuit 3 and a constant fixed voltage (-V), respectively. Another subtractor circuit 6 calculates the difference between the outputs Va, Vb of both integrator circuits 4, 5, and a voltage comparator circuit 7 effects a comparison of levels between the output of the subtractor circuit 6 and a reference voltage Vref for setting a predetermined contact pressure to generate an output representative of the result of the judgement of the actual contact pressure. |
