| 摘要 |
1351671 Automatic voltage regulation LICENTIA PATENT-VERWALTUNGSGmbH 12 Aug 1971 [18 Aug 1970] 37997/71 Heading G3X A shunt arrangement for limiting a supply voltage comprises a number of stages each including a power transistor and power resistors. Increase in supply voltage actuates each stage in succession to dissipate excess power. The transistor of one stage is allowed to reach a saturated state before a subsequent stage is actuated. In the embodiment described, a voltage from a solar generator in a space vehicle is fed on a line 11 to comparators 10 receiving reference inputs 12. A logic circuit 15 passes an output voltage to amplifiers 6, 7 which are connected directly to a first shunt stage 2a and through threshold circuits 8 and amplifiers 9 to further shunt stages 2b, 2c, 2d. By way of example, the stage 2b, Fig.2, includes a power transistor 20 connected in series with power resistors 21, 22 across the main supply line 35 connected to line 11 and ground 36. In operation, an output from the logic unit 15 causes power dissipation in the transistor 20 of stage 2a. Further increase in the supply voltage results in saturation of that transistor and also turns on transistor 28 in the threshold circuit 8 of stage 2b. The threshold level is fixed by resistor 32 which may be replaced by a Zener diode, Fig. 3 (not shown). The output from the threshold circuit is amplified by transistor 24 which controls the power transistor 20. Similarly, when this transistor saturates, the next stage 2c is triggered. By switching in additional stages only after saturation, sudden changes are avoided, since the power transistors dissipate only a small amount of heat in the saturated state. |
