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  • Attix70

    aktív tag

    válasz szuszinho #9475 üzenetére

    Az SSR szilárdtest relé, elektronikus áramkörökből felépített relé ami a felépítéséből adódóan váltakozó feszültségre használható valamint aktív üzemben mindig van rajta feszültség esés (és disszipáció) és még nullátmenet kapcsolására is alkalmas lehet.. A másik az sima relé (mechanikus kapcsolást végez)

  • Teasüti

    nagyúr

    válasz szuszinho #9475 üzenetére

    Első találat, részlet az SSR wikipedia cikkéből:
    "Advantages over mechanical relays

    Most of the relative advantages of solid state and electromechanical relays are common to all solid-state as against electromechanical devices.

    -Inherently smaller and slimmer profile than mechanical relay of similar specification, allowing tighter packing. (If desired may have the same "casing" form factor for interchangeability.)
    -Totally silent operation.
    -SSRs switch faster than electromechanical relays; the switching time of a typical optically coupled SSR is dependent on the time needed to power the LED on and off - of the order of microseconds to milliseconds.
    -Increased lifetime, even if it is activated many times, as there are no moving parts to wear and no contacts to pit or build up carbon.
    -Output resistance remains constant regardless of amount of use.
    -Clean, bounceless operation.
    -No sparking, allows it to be used in explosive environments, where it is critical that no spark is generated during switching.
    -Much less sensitive to storage and operating environment factors such as mechanical shock, vibration, humidity, and external magnetic fields.

    Disadvantages

    -Voltage/current characteristic of semiconductor rather than mechanical contacts:
    When closed, higher resistance (generating heat), and increased electrical noise
    When open, lower resistance, and reverse leakage current (typically µA range)
    -Voltage/current characteristic is not linear (not purely resistive), distorting switched waveforms to some extent. An electromechanical relay has the low ohmic (linear) resistance of the associated mechanical switch when activated, and the exceedingly high resistance of the air gap and insulating materials when open.
    -Some types have polarity-sensitive output circuits. Electromechanical relays are not affected by polarity.
    -Possibility of spurious switching due to voltage transients (due to much faster switching than mechanical relay)
    -Isolated bias supply required for gate charge circuit
    -Higher transient reverse recovery time (Trr) due to the presence of the body diode
    -Tendency to fail "shorted" on their outputs, while electromechanical relay contacts tend to fail "open"."

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