AC-DC Switching regulator uninterruptible power supply
Microwave heating device with constant temperature control of the magnetron
Standby power supply
Microwave oven for vehicles
Microprocessor power relay control circuit for a microwave oven
Controlled magnetron power supply including dual-mode inverter
Powered microwave oven Patent #: 4904837
ApplicationNo. 422963 filed on 10/18/1989
US Classes:219/717, Plural power supplies219/722, Interlock circuitry and structure219/723With additional safety feature
ExaminersPrimary: Leung, Philip H.
Attorney, Agent or Firm
International ClassH05B 006/66
AbstractA microwave oven is described suitable for use on transports where DC power is available. The microwave oven employs a first inverter to generate internal AC power that is then used to operate the microwave components other than the magnetron microwave source. The internal AC power is passed with relatively low current through the oven interlocks to activate and drive a power inverter that, through an additional output transformer winding, delivers high voltage power to the magnetron. In a preferred embodiment a relay, that is connected to sense when external AC power is available, causes an automatic switching that decouples the internal AC power from the power inverter to enable conventional operation from external AC line power. When external AC line power is no longer applied, the microwave oven automatically switches to operate from the available DC power. An efficient cooling fan is provided that is driven by a DC motor. The motor is provided DC power that is derived from a reverse coupling of AC line power through a transformer used at the output of the first inverter. During a DC power mode, the DC power available at a center tap of the primary winding of this transformer is used to drive the DC motor. Operating controls are described for the power inverter.