| 摘要 |
<p>PURPOSE:To stably operate an electric brake of low torque to a low speed by enhancing a field rate in a low speed range when operating the brake. CONSTITUTION:A current of the armature winding of a DC series motor is controlled by an armature chopper 11, and a current of a field winding 4 is controlled by a field chopper 9. The output of a power source 16 is supplied through a preliminary exciting contactor 15, a rectifier 14 and a current limiting resistor 13 to a field winding 7 as a preliminary exciting current. The field rate pattern generated from a field rate pattern generating means is compared with a field rate obtained by calculating with an armature current Ia and a field current IF to control the conduction rate of the chopper 9. The field rate pattern is set to that in which a field rate in a low speed range becomes 100% or higher at the electric brake controlling time.</p> |
