摘要:
A microwave oven which includes a defrosting detector in the oven cavity in the proximity of a frozen product to be defrosted, the detector including a material which absorbs microwave energy, the absorption of microwave energy by the detector and by the product causing their temperatures to rise. Variations in the detector temperature are measured by a measuring element producing an electrical signal corresponding thereto, such signal being used to control the defrosting process. The microwave absorbent material is in the form of a layer deposited on a carrier which is positioned behind the product so that most of the detector area can only receive microwave energy through the product, whereby the rate of change of detector temperature with time decreases as the product defrosts and becomes constant when defrosting has been completed. The carrier may be one of the walls of the oven cavity or the oven tray. The material may be a resistive ink deposited on the oven tray by screen-process printing.
摘要:
A microwave oven with a door-closing safety device is provided wherein a movable door comprises a device wherein the beam of at least one light emitter is guided by means of light guides towards a light beam detector. The light guides are arranged along a substantial portion of at least one side of the oven door frame. The beam of light in its non-guided path between the emitter and the detector passes through diaphragms, integral with the oven door, each diaphragm having an aperture such that the light beam passes through it when the door is properly closed but wherein the light beam is intercepted by the edge of the diaphragm when the door is not properly closed. The detector activates a signal that actuates the magnetron when the light beam is received; however, when the beam is intercepted, activation of the magnetron is prevented thereby preventing leakage of microwave energy.
摘要:
An apparatus for detecting intruders comprising a housing provided with at least one window, a passive infrared detector (for detecting the radiation emitted by an intruder around a wavelength .lambda..sub.1), and an anti-obscuring device (detecting by infrared radiation having a wavelength .lambda..sub.2 the presence of an obscuring of the appparatus for detecting intruders). The apparatus further includes an electronic circuit intended to operate an alarm when the presence of an intruder or an obscuring element has been detected. The apparatus for detecting intruders has a detector for detecting an obscuring element arranged at small and at large distances. It further includes a self-verification circuit. An obscuring element is detected, inter alia, by a mirror arranged at the end of the zone to be supervised, which returns radiation .lambda..sub.2 emitted by an emitter to a detector, both being situated very close to the detector of radiation having a wavelength .lambda..sub.1.
摘要:
The invention relates to a microwave oven comprising control means which reduce the risk of no-load operation and which co-operate with an actuating element which switches on the magnetron with the aid of power-supply means depending on open and closed states of the oven door. The invention is characterized in that the control means comprise a bistable electromechanical device which responds to closures of the door by counting the number of these closures and which enables the magnetron to be energized after an even number of closures of the door, one cycle of operation of the bistable electromechanical device comprising two open states and two closed states of the door. The bistable device may comprise a lever device which actuates a pendant-type electrical switch or a remote-controlled switch.
摘要:
A method of renewing a used liquid for reuse of the same includes establishing a body of a reference liquid for comparison with renewed used liquid, and establishing a separate body of the used liquid adjacent the body of reference liquid. An incident light beam is produced for consecutive traversal of the body of used liquid and the body of reference liquid, the particles in the two liquid bodies thereby diffusing the light beam to provide respective luminous fluxes off the axis of the incident light beam. The two luminous light fluxes are separately detected and compared. This procedure is automatically terminated when the detected luminous light fluxes are substantially equal to each other.
摘要:
A door-open alarm device comprises alarm means connected to an electric circuit which comprises, arranged on the stationary part (11), a voltage source, a switch (13) having two positions in which the circuit is interrupted and closed respectively, electrical time delay means responsive to a current flow in the circuit to produce a voltage variation across said alarm means after a time delay, thereby triggering said alarm means. Arranged on the door (12) is a mechanical actuating element (14) for said switch, which opens said switch when the door is wide open or closed, and which closes said switch when the door is ajar.