| 摘要 |
<p>The control circuit includes an actuating element (1) which, within a pressure control system, comprises an inductance with a very low ohmic (d-c) resistance, e.g. the winding of a d.c. motor, stepper motor or an electromagnet winding. A comparator (K) is provided to compare the voltage across a resistor (R3), as produced by the load current, with a reference voltage across a potential divider network (R1,R2). The comparator (K) is assigned to switch off the actuating element (1) (load), when the reference voltage is exceeded, via an amplifier (A). To protect the actuating element (1) from damage, the actuating element (1) is switched on in normal operating modes by the comparator (K) via the amplifier (A) i.e. the associated transistor (T3).</p> |
