Zero power wireless sensors, devices, and systems are used for crop water content monitoring. The sensors consume no power while monitoring for the presence of dry crop conditions. Infrared reflectance from plants is measured and when selected spectral conditions are met, a circuit is closed, activating an alarm, an RFID tag, or a radio transmitter. The deployed sensors consume no power while monitoring, reducing or eliminating the need to change batteries.

Zero power wireless sensors, devices, and systems are used for crop water content monitoring. The sensors consume no power while monitoring for the presence of dry crop conditions. Infrared reflectance from plants is measured and when selected spectral conditions are met, a circuit is closed, activating an alarm, an RFID tag, or a radio transmitter. The deployed sensors consume no power while monitoring, reducing or eliminating the need to change batteries.

This relay unit includes: a first bus bar; a relay electrically connected to the first bus bar; and an apparatus cover for covering the first bus bar and the relay. The apparatus cover includes: an upper member in a box shape having a covered upper end, the upper member having an opening formed in a lower end; and a lower member bonded to the upper member such that the opening of the upper member is covered with the lower member. The lower member is formed of a resin having heat conductivity that is higher than that of the upper member. The first bus bar is connected to the lower member via a first inner heat conductive sheet such that heat can be transferred to the lower member, said first inner heat conductive sheet being disposed between the first bus bar and the lower member.

The present disclosure relates to a technical field of cells, and discloses a protection device and a battery. The protection device includes: a first connecting member; a second connecting member; a first element; and an elastic sheet. When the elastic sheet has a temperature lower than a first temperature, the elastic sheet is connected to at least one of the first connecting member and the second connecting member; when the temperature of the elastic sheet is equal to the first temperature, the elastic sheet is deformed to allow the first connecting member, the second connecting member, the elastic sheet and the first element to form a series circuit. When the protection device is not triggered, the temperature of the elastic sheet is lower than the first temperature, and the elastic sheet is connected to at least one of the first connecting member and the second connecting member.

The temperature switch includes a housing, an actuator, a switch, and a force buffer situated between the actuator and the switch. The switch is movable between a first and second state in response to imposition and release of an actuating force F.sub.A. The force buffer transmits the actuating force F.sub.A from the actuator to the switch when compressed a first distance in the first direction by extension of the actuator in response to an increase in temperature T.sub.1. At temperature T.sub.1, the force buffer transmits the force F.sub.A to move the switch from the first state to the second state. The actuator retracts a second distance in the second direction in response to a decrease in temperature T.sub.2. At temperature T.sub.2, the force buffer releases the force F.sub.A and the switch moves from the second state to the first state.

According to one aspect, a thermal protection device is provided having an electrical input for receiving input DC power and an electrical output for connection to a load. A heating circuit is coupled to the electrical input for developing one of first and second different heat magnitudes depending upon a temperature magnitude in the housing. An additional circuit is in thermal communication with the heating circuit for providing output DC power to the electrical output when the first heat magnitude is developed and for interrupting the output DC power when the second heat magnitude is developed.

According to one aspect, a thermal protection device is provided having an electrical input for receiving input DC power and an electrical output for connection to a load. A heating circuit is coupled to the electrical input for developing one of first and second different heat magnitudes depending upon a temperature magnitude in the housing. An additional circuit is in thermal communication with the heating circuit for providing output DC power to the electrical output when the first heat magnitude is developed and for interrupting the output DC power when the second heat magnitude is developed.

This invention is a thermally actuated switch in which a sealed vessel contains a fixed contact and a heat-sensitive-plate assembly that has a structure in which a movable contact is anchored to one lengthwise end of a heat-sensitive plate, one end of a metal support is anchored to the other end of said heat-sensitive plate, and the heat-sensitive plate is then drawn. The heat-sensitive-plate assembly has a dish-shaped drawn section near the middle of the heat-sensitive plate and has folded sections between the area where the movable contact is anchored and the widthwise edges of the heat-sensitive plate and also between the area where the metal support is anchored and the widthwise edges of the heat-sensitive plate.

This invention is a thermally actuated switch in which a sealed vessel contains a fixed contact and a heat-sensitive-plate assembly that has a structure in which a movable contact is anchored to one lengthwise end of a heat-sensitive plate, one end of a metal support is anchored to the other end of said heat-sensitive plate, and the heat-sensitive plate is then drawn. The heat-sensitive-plate assembly has a dish-shaped drawn section near the middle of the heat-sensitive plate and has folded sections between the area where the movable contact is anchored and the widthwise edges of the heat-sensitive plate and also between the area where the metal support is anchored and the widthwise edges of the heat-sensitive plate.

RFID devices are provided for use in combination with a food item or other temperature-sensitive item. The RFID devices include an RFID chip and an antenna electrically coupled to the RFID chip, along with a temperature-sensitive member. The temperature-sensitive member is configured to be in a first condition below a selected temperature and a second condition above the selected temperature to signify that the RFID device and associated food item or other temperature-sensitive item have been exposed to a temperature above the selected temperature. The temperature-sensitive member may be incorporated into the antenna to render the antenna at least partially inoperative above the selected temperature. The temperature-sensitive member may instead be configured to exhibit different colors below and above the selected temperature, or a single RFID device may include both types of temperature-sensitive members. Such RFID devices may also incorporate tamper-resistant features and/or accommodate human- and/or machine-readable printed symbols.