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Topic: Combining two scematics (Read 1 time) previous topic - next topic

jackrae

"Thermistor" ?  I think not.  A transistor is maybe what you meant.  Either way, they are quite different devices - but both classed as semiconductors.

06awaism

I am really sorry. I meant a transistor.

Grumpy_Mike

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It is a thyristor.

That is the same as an SCR.
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Similar to thermistor but has a slightly different operation

No it is not remotely similar to a thermistor. And you do not draw it like that. The gate line is a diagonal line leading to the under side of the cathode.
http://en.wikipedia.org/wiki/File:SCR_symbol.svg

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the buzzer will sound for a predetermined time varying on the capacitor value and the LED will stay lit

You need two circuits, one that will commutate (turn off) the SCR after a pre determined interval. You can do this by having the SCR charge up a capacitor feeding into a unijunction that is wired across the SCR. When it fires the SCR is shorted out and so stops conducting. The other circuit is what you have already. The two are triggered from the same point.


06awaism


Swap R4 and SW5 in the second schematic, and remove BZ3 in the first schematic. Then combine them, such that SW2 and SW5 become the same thing, as do SW3 and SW4. But as Mike says, if you will be using an Arduino anyway, then it's much simpler to just connect the switches, buzzer and LED to the Arduino, and do the buzzer and LED control in software.


Thanks a lot for your reply. Well, I thought it would be complicated if I used countdown timer along with this circuit. So I thought I will make 2 circuits. One with arduino which will do the countdown timer and second which is the loop wire circuit itself.

06awaism

#9
Dec 30, 2012, 11:51 pm Last Edit: Dec 30, 2012, 11:53 pm by 06awaism Reason: 1
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Similar to thermistor but has a slightly different operation

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No it is not remotely similar to a thermistor. And you do not draw it like that. The gate line is a diagonal line leading to the under side of the cathode.
http://en.wikipedia.org/wiki/File:SCR_symbol.svg



Sorry, I was meant write a transistor.

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