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I had recently asked a quiestion here: Will this circuit for quiz buzzers work? and I got this answer.

I am trying to understand the circuit and I have understood most of it but there is only one part that I am not able to understand.

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I don't understand electronics in theory properly so can you explain in simple english why this ground and resistor have been connected?

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Kartik
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  • I think that without that resistors, the tension of the base is not fixed and probably will float when the keys/buttons are open. –  May 04 '14 at 21:52
  • @Luis What is the meaning of 'tension of base'? – Kartik May 05 '14 at 00:51

1 Answers1

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Strictly speaking, they aren't required, but those resistors help speed up the turn-off of the associated transistors, and also help with noise immunity by pulling the base connections all the way to ground when the switches are open.

Dave Tweed
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