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Why diode is not a passive element?

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niro

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why the diode is not a passive element ??
 

Nimer

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Re: question

hi
because it does not allow energy to go freel aroumd

regards
 

    niro

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v_c

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Re: question

I think diode is a passive device because it always dissipated power. The current-voltage characteristics of the diode are always on the 1st and 3rd quadrant so that that the instantaneous power dissipation (i*v) is always positive.

Best regards,
v_c
 

mtkee2003

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question

sometimes it is a passive element and sometime it is not a passive element.

for example when you make a diode with a BJT(with shorting its collector and its base) then it is a not passive element and for a diode like 1n4148 we must say it is a passive element.

regards.
 

dragonhart

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Re: question

Diode is consider as active component because it requires supply to voltage to be forward biased and perform its function as a switch or as a rectifier unlike resistor/capacitor/inductor which do not need any voltage to turn on/off. We defined active component when it require external supply voltage to perform function while passive component do not need supply voltage
 

gunsuresh

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Re: question

Barrier voltage is generated with out any bias, hence diode is a active device.
 

A.Anand Srinivasan

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Re: question

i think a active device has power gain can someone explain then how can a diode be a active device
in which circuit does it have power gain
 

satyasri

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Re: question

DIODE IS ACTIVE ELEMENT BECAUSE IT ADDS ENERGY BY APPLYFYING
IT DOES NOT CONSUME ANY POWER
 

v_c

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Re: question

Diode does not consume any power? Are you kidding?
The diode has a forward voltage when you forward bias it and that produces a power loss -- that is why it is a passive device. The current-voltage product of a diode is always positive -- it always dissipates power.

Take a look at a simple diode, it will have a forward voltage of 0.7-1.0V. Let's say you are putting 1A through it. Everytime you do this you have an instantaneous power dissipation of 0.7-1.0W. Now usually diodes are used in circuits where they are not always passing current. In that case, you can take the power dissipation versus time and calculate the average power dissipation.
 

amun

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Re: question

diode has a voltage drop when u pass a current through it so it is a passive element
 

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