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What Part of ______________________ Don't You Understand ? - One for mapj1 ?

AncientMariner
I came across this mug recently, looked at the circuit diagram and started to wonder whether I understood it? Or perhaps more to the point, did the draughtsman/women/person understand the design?

https://www.amazon.co.uk/ENGINEERING-UNDERSTAND-Novelty-Printed-Ceramic/dp/B01IC23TSC


Clive
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  • 0
    "one for MAPJ" eh ?  challenge accepted.


    I think it is one half of these new circuits to disconnect an electric vehicle charger if the mains voltage goes out of spec. we have to assume that the square IC 1 is a voltage regulator, and the triangular IC1 is a comparator, such that when the positive input is at a higher voltage than the negative input, the output is near the positive rail voltage and near the negative rail voltage otherwise.

    The comparator sees the Zener voltage on its negative input, and a DC voltage proportional to the incoming mains on the positive input, and the unregulated DC is on its indecisive input power supply pin.


    The two transistors form an un-necessary inverter, and in the B model we would eliminate one transistor and reverse the sense of the comparator inputs. Or maybe the contact state for  mains completely  off is also important...

    The diode and cap across the relay coil absorb the EMF of the collapsing magnetic field of the relay coil when the transistor turns off.

    The main part I do not understand is the reuse of the label IC1..


    M.
Reply
  • 0
    "one for MAPJ" eh ?  challenge accepted.


    I think it is one half of these new circuits to disconnect an electric vehicle charger if the mains voltage goes out of spec. we have to assume that the square IC 1 is a voltage regulator, and the triangular IC1 is a comparator, such that when the positive input is at a higher voltage than the negative input, the output is near the positive rail voltage and near the negative rail voltage otherwise.

    The comparator sees the Zener voltage on its negative input, and a DC voltage proportional to the incoming mains on the positive input, and the unregulated DC is on its indecisive input power supply pin.


    The two transistors form an un-necessary inverter, and in the B model we would eliminate one transistor and reverse the sense of the comparator inputs. Or maybe the contact state for  mains completely  off is also important...

    The diode and cap across the relay coil absorb the EMF of the collapsing magnetic field of the relay coil when the transistor turns off.

    The main part I do not understand is the reuse of the label IC1..


    M.
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