| 摘要 |
A power supply for a magnetron has a PFC DC voltage source and an HV (High Voltage) converter. The voltage source is mains driven and supplies DC voltage above mains voltage on line, smoothed by capacitor to the HV converter. The latter supplies switched alternating current to transformer. This supplies higher voltage alternating current to a rectifier, in turn supplying the magnetron with high, magnetron powering, anode voltage on line. The DC voltage source has an PFC inductor, which is switched by a transistor switch under control of an integrated circuit. It is the inductor which enables the voltage source to provide a variable DC voltage. An input rectifier is provided for rectifying mains voltage. The output voltage of the voltage source is monitored and fed back to the integrated circuit by a voltage divider. |
| 主权项 |
1. A power supply for a magnetron, the power supply including:
a Magnetron, Switched Converter Power Circuit (MSCPC), the MSCPC having a control input and being adapted to generate increased voltage at a certain multiple of DC voltage applied to it when a control voltage for full power operation of the magnetron or a control voltage deviating in one direction from the control voltage is applied to the control input, the one direction being ineffective on the multiple, and an increased voltage at a decreasing multiple with deviation of the control voltage from the control voltage in an other direction opposite the one direction, the other direction being effective on the multiple, i.e. reducing it; a DC voltage source arranged to supply the DC voltage or the DC voltage together with an increase therein to the MSCPC; means for measuring power or current from the DC voltage source passing through the MSCPC for driving the magnetron; converter control means for applying a control voltage to the MSCPC in accordance with a function of the difference between a desired magnetron power and the said measured power or current; and DC voltage control means for passing deviation of the control voltage in the ineffective-on-the-multiple direction to the DC voltage source for causing it to supply the increased DC voltage to the MSCPC; the arrangement being such that in use: when the converter control means applies the voltage to the MSCPC, the latter is supplied with the DC voltage and applies power for full power operation to the magnetron, when the converter control means applies voltage deviated in the multiple-effective direction, the MSCPC is supplied with the DC voltage and applies less power than power for full operation to the magnetron and when the converter control means applies voltage deviated in the multiple-ineffective direction, the MSCPC is supplied with increased DC voltage and applies higher power to the magnetron. |
