| 摘要 |
The circuit arrangement comprises a power supply unit with a first power supply only for the analogue signal processing part and for the control part of a respective device. For the digital signal processing part, a second, separate switched mode power supply is provided, which is switched off, when only the analogue signal processing part is active, and which is in operation, when the digital signal processing part is on. For switching on and off of the second switched mode power supply, the power supply comprises a switching circuit (18), which is coupled in a special embodiment to a control loop (15) on the secondary side, for switching off the second power supply at the primary side via a galvanic isolating means (14). The switching circuit is provided with a supply voltage (12VS) from the first power supply and receives the on/off command from the control part, e. g. a microprocessor. The power supply unit is used advantageously within a D-VHS recorder, and the first power supply provides the power for the control part and the analogue circuit processing of the recorder. The second switched mode power supply is associated with the digital signal processing part. The second switched mode power supply is switched on for example, when a D-VHS tape is inserted into the recorder. <IMAGE> |
