Photovoltaic relay
    106.
    发明专利

    公开(公告)号:GB2154820A

    公开(公告)日:1985-09-11

    申请号:GB8501283

    申请日:1985-01-18

    Abstract: A high voltage bidirectional output semiconductor field effect transistor (BOSFET) 24 is disclosed which is turned on from the electrical output of a photovoltaic stack 19 which is energized from an LED 21. The process for manufacture of the device is also disclosed. The BOSFET device consists of two lateral field effect transistors 30, 31 formed in an implanted N( - ) region (71) in a P( - ) substrate (70). A diode 35, PNP transistor 36 and resistor 37 are integrated into the same chip containing the lateral BOSFET device to form a solid state relay circuit having characteristics similar to a reed relay. A photovoltaic isolator 20 consists of a stack of semiconductor wafers (320) which are alloyed together by an aluminum silicon alloy foil (43). Each of the wafers consists of a P-type body having P + and N + diffusions on its opposite surfaces. The wafers are stacked with the same forward conduction polarity. Individual photoisolator stacks (345) are sliced from the completed stack to any desired dimension. Each individual stack is mounted with a light source (360), preferably an LED, which is arranged to illuminate the edge of each wafer within the stack.

    107.
    发明专利
    未知

    公开(公告)号:IT8519170D0

    公开(公告)日:1985-01-21

    申请号:IT1917085

    申请日:1985-01-21

    Abstract: The gate capacitance of a Field effect transistor (24) used as a switch is rapidly charged via a diode (35) to turn the FET on, and is rapidly discharged to turn the FET off by a switching transistor (36) connected across the diode and the FET such that it becomes conductive only when the diode becomes reverse biased, thereby providing a discharge path for the gate capacitance. The circuit is used in a photovoltaic relay, the FET being turned on by a photovoltaic isolator (20) having a LED 21 energised by an input signal optically coupled to and dielectrically isolated from a series-connected stack of photo diodes connected to the switching FET, which may comprise a bilateral semiconductor FET (BOSFET).

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