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  1. #1
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    Overvoltage Protection

    Vin = 9.2V - 9.8V. For the circuit mentioned in the figure, if Input Voltage crosses 10V , Zener gets activated.
    For the given circuit, when zener is activated, will more current flow through the base of PNP and cause any trouble to the PNP transistor ? Or the circuit would do fine ?

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  2. #2
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    Re: Overvoltage Protection

    Provided you use the specified transistor it should be fine, its internal base resistor will limit the current to a safe level.

    Brian.
    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
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    Re: Overvoltage Protection

    You have no DC supply connection to the transistor emitter, so it won't work.
    Zapper
    Curmudgeon Elektroniker



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    Re: Overvoltage Protection

    You have no DC supply connection to the transistor emitter, so it won't work.
    Look again, the circuit is fine.

    If you don't have one of those "digital transistors" with built-in base resistors, you need to add an external base resistor.


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