METHOD AND DEVICE FOR CONTROLLING PULSE WIDTH FOR REVERSIBLE DC CURRENT REGULATOR

摘要

The invention relates to a method for pulse width control of a direct current two-way control element having four electronic switches 1 to 4 in a bridge circuit for supplying a resistive-inductive load 5 located in the bridge diagonal, and circuitry for carrying out the method. In this case, the ripple of the load current should be small. In each direction of the load current, in each case one of two electronic switches 1, 3 or 2, 4 located opposite one another in the diagonal of the bridge circuit is pulsed and one is driven by a continuous signal. Circuitry for carrying out the method contains a polarity detection stage 17 for detecting the polarity of the control voltage USt. The polarity detection stage is connected via a first switch-off delay element 18 to a latching stage 15 for the first electronic switch 1, and directly to the control input for the third electronic switch 3, and via an inverter stage 20 and a second switch-on delay element 19 to a latching stage for the fourth electronic switch, and directly to the control input of the second electronic switch 2. By this means, an interruption pause in the driving of the electronic switches 1 to 4 is achieved when the polarity of the control voltage USt changes. The direct current two-way control element according to the invention is suitable, for example, for the control of direct current motors. IMAGE