Abstract: A probe is mountable to a printed circuit board testing device which performs a test on a predetermined land and/or a predetermined via hole of a printed circuit board. The probe includes a probe tip and a protrusion. The probe tip is contactable with the land and/or the via hole and projectable from the probe. The protrusion is disposed at a surface of the probe, the surface of the probe being disposed opposite to where the probe tip is projectable. The protrusion is grounded by a reaction pressure that is generated when the probe tip contacts the land and/or the via hole.

Abstract: A probe is mountable to a printed circuit board testing device which performs a test on a predetermined land and/or a predetermined via hole of a printed circuit board. The probe includes a probe tip and a protrusion. The probe tip is contactable with the land and/or the via hole and projectable from the probe. The protrusion is disposed at a surface of the probe, the surface of the probe being disposed opposite to where the probe tip is projectable. The protrusion is grounded by a reaction pressure that is generated when the probe tip contacts the land and/or the via hole.

Abstract: The microwave oven includes a heat chamber, an infrared detector for detecting infrared rays irradiated from an object to be heated in the heating chamber, a chopper for alternately interrupting the path of infrared rays to the detector, an oscillator for producing a reference signal used for driving the chopper, and a circuit for regulating the output of the detector and the phase of the reference signal. The infrared detector does not require any phase adjustment to accommodate frequency shifts due to fluctuations in the power frequency.

Abstract: A microwave oven is provided according to which food is cooked while a temperature sensor is inserted in the food and the heating of the food is interrupted in response to an output signal of the temperature sensor. The temperature sensor comprises a hollow skewer, a bellows which is attached to the skewer and in which is sealed a liquid of high coefficient of thermal expansion, and a sound generating body of a plate spring for generating a sound when the hollow skewer is heated by the food, the liquid is expanded, the bellows is stretched, and the force generated thereby overcomes the biasing force. The microwave oven stops heating and cooking when a sound is generated.