Mitsubishi Materials Corporation

Fujio Ikeda

Takaaki Itoh

Takashi Shibayama

Masatoshi Abe

Kazuyuki Arai

Naruo Yoshioka

A MELF (Metal Electrode Face Bonding Device) surge absorbing element which can be connected across a pair of input lines of an electronic device. The surge absorbing element is secured in electrical contact with the input lines by a conductive heat releasable adhering means, e.g., a solder. A spring is positioned in biased relationship against the surge absorbing element. When the surge absorbing element is subjected to overvoltages or overcurrents continuously across the input lines, the surge absorbing element heats up, which, in turn, heats the adhering means. When the temperature reaches a predetermined value, the adhering means releases its securement of the surge absorbing element, e.g., the solder melts, and no longer holds the element. When this occurs, the bias of the spring means positioned against the now unsecured surge absorbing element serves to move the element away from and out of electrical contact with the adhering means and, in turn, the input lines. This prevents further heating of the surge absorbing element.

Surge absorber

A surge absorber in which a thermal response switch is inserted in an input line at the input side of a surge absorbing element. The switch includes a conductive spring piece and a conductive hook piece. The base end of the conductive spring piece is fixed on either the first lead or the second leads and the tip of the conductive spring piece is provided with a pawl. The base end of the conductive hook piece is fixed on either the first lead or the second leads and the tip of the conductive hook piece is engaged with the pawl. At least one of the conductive spring piece and the conductive hook piece is made of a thermal response piece. Upon stopping of the applied continuous overvoltages or overcurrents, the switch can automatically be restored depending on an extent of the overcurrent by a manual operation.

A surge absorber including a surge absorbing element for protecting communication equipment from transient surges and a thermal response switch with an automatic restoration function connected in parallel with the surge absorbing element. The inventive surge absorber prevents abnormal and deleterious heating of the surge absorbing element when continuous overvoltages or overcurrents are applied to the surge absorber.

Surge absorber for protection of communication equipment connected to

A surge absorbing element is parallel connected to an electronic device via a pair of communication lines. A normally closed thermal response switch is serially connected between the electronic device and the signal source on the input side of the surge absorbing element. When a surge voltage is instantaneously applied to the communication lines, the thermal response switch remains in the closed position and the surge absorbing element acts to suppress the surge voltage. When an overvoltage or over current is continuously applied to the communication lines, the thermal response pieces of the thermal response switch open and simultaneously release the movable body. Consequently, the electronic device is disconnected from the signal source, thus stopping the continuous overvoltage or overcurrent from flowing to the electronic device and the surge absorbing element. Simultaneously, the reset pin is projected through the casing. After the temperature of the switch decreases, the switch is reset to the closed position by pushing a reset pin which reconnects the electronic device to the communication lines.

Thermal response switch and a surge absorbing circuit using the same

A protective structure for a surge absorber which is composed of the surge absorber, connecting means for connecting the surge absorber to an electronic device and means for protecting the surge absorber as well as the electronic device from fire caused by a continuous overvoltage. The surge absorber protecting means is composed of a first electroconductive spring member which does not deteriorate from heat generated by repeated transient surge voltages to which it might be subjected. This spring member may be connected to a communication line and is movable between a first spring-loaded position wherein it connects the electronic device and the surge absorber to the communication line and a second non-spring loaded condition wherein the connection is broken. Also included are release means for releasing the first member from its first spring-loaded position which release means is activated by heat generated from a continuous overvoltage.

Protection structure for a surge absorber

The surge absorber having a surge absorbing element, and first and second wire means for electrically connecting the surge absorbing element across the input lines of an electronic device. The first and second wire means are connected to the surge absorber by conductive heat releasable means, for example, a low melting point solder. The second wire means includes a spring loaded member such that, on release of the first or second wire means by the first or second heat releasable means, respectively, by melting of the solder due to heat generated by the surge absorbing element, the surge absorbing element moves away from the first or second wire means. The surge absorber prevents an abnormal heating of the surge absorbing element when continuous overvoltages or overcurrents pass therethrough.

Growing community of inventors

Saitama, Japan

Fujio Ikeda