Abstract: Disclosed is a module (10) having pins (16-24) connected to respective conductor tower strips (46, 48, 50, 52). Pairs (46, 50 and 48, 52) of the conductor tower strips are spring biased toward each other to capture therebetween respective PTC current limiting elements (64, 70). A spring member 60 is connected to a ground pin (24) at one end, and to an overvoltage sensitive assembly at the other end, via a soldered heat transfer member (92). The overvoltage sensitive assembly includes overvoltage semiconductor devices (76, 77, 79) soldered thereto. When an overvoltage condition is sensed, the heat generated by the devices melts the solder between the heat transfer member (92) and the spring member (60), whereby lateral arms (90) of the spring member (60) move and engage the conductor tower strips (50, 52). The tip and ring pins (16, 18) of the module (10) are not only shorted together, but are shorted to ground.

Abstract: An overvoltage protection device having multiple shorting dots in the emitter region and multiple buried regions substantially aligned with these shorting dots. The placement, number, and area of these buried regions reduce and more accurately set the overshoot voltage value of the device while maintaining the high surge capacities of the device. Further, doping types and concentrations have been modified from that known in the prior art to reduce overshoot providing a more accurate and sensitive overvoltage protection device than that known previously in the prior art.

Abstract: An overvoltage protection device having multiple shorting dots in the emitter region and multiple buried regions substantially aligned with these shorting dots. The placement, number, and area of these buried regions reduce and more accurately set the overshoot voltage value of the device while maintaining the high surge capacities of the device. Further, doping types and concentrations have been modified from that known in the prior art to reduce overshoot providing a more accurate and sensitive overvoltage protection device than that known previously in the prior art.

Abstract: A two-terminal, bidirectional semiconductor trigger switch is provided. The trigger switch is a relatively sensitive multilayer semiconductor breakover device that switches on fully when its breakover voltage is reached. The design of the trigger switch allows its breakover voltage point to be readily adjustable during fabrication of the device.The semiconductor trigger switch is particularly suited to provide a low voltage trigger for a TRIAC. The trigger switch is connected in series with the gate of the TRIAC and mounted on the gate lead to provide a unitary, three-terminal device incorporating the TRIAC/trigger switch combination.

Abstract: An overvoltage protection circuit for electronic equipment having tip and ring lines includes a first voltage sensitive switch having first and second teminals. The first terminal of the first switch is connected to the tip line. A second voltage sensitive switch includes first and second terminals. The first terminal of the second switch is connected to the second terminal of the first switch, and the second terminal thereof is connected to the ring line. A third voltage sensitive switch includes first and second terminals. The first terminal of the third switch is connected to the second terminal of the first switch and to the first terminal of the second switch. The second terminal of the third switch is connected to ground potential. The switches are conductive when a respective voltage threshold is exceeded.

Abstract: A telephone maintenance termination unit utilizes a low voltage, bidirectional trigger switch for performing diagnostic functions on a telephone line. The trigger switch provides low voltage, low current triggering in conjunction with a high holding current requirement. The trigger switch may comprise either two silicon controlled rectifiers connected in inverse parallel relationship with their gates connected, a bidirectional diffused PNPN semiconductor device, or an NPN semiconductor device, any one of which is used to trigger a power control TRIAC. In another embodiment, the switching device may be a two-terminal, unitary semiconductor device incorporating the functions of both the TRIAC and the bidirectional trigger switch.

Abstract: A telephone maintenance termination unit utilizes a low voltage, bidirectional trigger switch. The trigger switch provides low voltage, low current triggering in conjunction with a high holding current requirement. The trigger switch may comprise either two silicon controlled rectifiers connected in inverse parallel relationship with their gates connected, a bidirectional diffused PNPN semiconductor device, or an NPN semiconductor device, any one of which is used to trigger a power control TRIAC. In another embodiment, the switching device may be a two-terminal, unitary semiconductor device incorporating the functions of both the TRIAC and the bidirectional trigger switch.

Abstract: A triac device includes a first silicon chip having regions of alternate conductivity type disposed in a PN-junction forming relationship which defines a center-fired triac. A second silicon chip having regions defining a diac is bonded to the gate region of the triac chip. A copper layer of about 1 to 5 mils in thickness is bonded to the portions of the top major face of the triac chip that surround the gate region. Cathode, anode and gate connections are provided to the two-chip subassembly which is then encapsulated. The copper layer permits a smaller cathode connection to be made to the top of the triac chip without reducing the current capacity of the device.The triac device is mass-produced by first forming a plurality of triac chips in a two-dimensional array in a large area silicon wafer. The copper layers and diac chips are formed on the wafer prior to its separation into separate diac-triac chip subassemblies.