| 摘要 |
<p>An apparatus for supplying an electric consumer (5) with a high DC voltage (U6) from a DC voltage source (1) with positive and negative output potential relatively to earth potential contains an evaluating circuit (10, 11, 12, 15, 16) with its own operating voltage source (UB) between a currentsupply connection (S) and a reference potential line (Ref). The evaluating circuit receives a measuring signal depending on the consumer voltage (U6) and/or consumer current for comparing it with a predetermined value. Depending on the result of the comparison, it feeds a control signal by way of a separating stage (17) to a setter (4) influencing the consumer voltage. An operational amplifier (35; 40) at the or each measuring signal input of the evaluating circuit has its one input (-) connected to a series resistor (8; 13) and its other input (+) to the reference potential line. For simply increasing the safety with which the evaluating circuit can be touched, the supply of the respective measuring signal to each measuring signal input (+, -) of the evaluating circuit 18 effected by way of a respective high ohmi^ series resistor (8, 9; 13, 14) of about 7 to 11 megaohm, the reference potential line (Ref) is connected to earth (o) and the separating stage is an optocoupler.</p> |
