摘要 |
In order to adjust the output voltage and output current of a galvanically isolated switched-mode power supply, on the primary side there is formed an auxiliary voltage (15) proportional to the secondary voltage, and said auxiliary voltage is studied by means of a window comparator, so that when the auxiliary voltage is within the reference window, there is applied fixed power adjustment, and when the auxiliary voltage falls outside the reference window (>max, <min), the quantity of electric power fed in by the isolation transformer of the primary side is restricted. Most advantageously the auxiliary voltage is formed by means of an auxiliary coil (12b) contained in the isolation transformer, and the reverse threshold voltages of two zener diodes represent the limit values of the reference window. <IMAGE>
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