I have connected a diode 1N4007 across 14.33 V supply & tested voltage as shown in figure in attached pdf. (File.pdf)The voltage was 14.08V. I was surprised how this happen as forward drop of diode is 0.7V at room temp at low currents . (this is what I know till now)
suddenly I realized my voltmeter has internal resistance of 10M ohm so i have connected a ammeter as shown & I noted the current 1.3uA. So drop at this current is 14.08V in next figure.
So I kept on adding 10M resistance as shown so overall resistance is 5M a shown in next figure.
In total when I=1.3uA, Vdrop = 0.25V
I=2.7uA, Vdrop = 0.31V
I=4.1uA, Vdrop = 0.36V
I also tested diode (whether its working right), by connecting across diode tester in voltmeter. It shows 0.535V in forward bias direction.
I thought also to check its current i.e when meter is used to check diode drop. So I connected ammeter in between:
New Vdrop= 0.568 (total across diode & ammeter)
I = 337.2 uA.
Help me to understand this & why diode drop is not 0.7V at low current, Diode forward voltage drop
suddenly I realized my voltmeter has internal resistance of 10M ohm so i have connected a ammeter as shown & I noted the current 1.3uA. So drop at this current is 14.08V in next figure.
So I kept on adding 10M resistance as shown so overall resistance is 5M a shown in next figure.
In total when I=1.3uA, Vdrop = 0.25V
I=2.7uA, Vdrop = 0.31V
I=4.1uA, Vdrop = 0.36V
I also tested diode (whether its working right), by connecting across diode tester in voltmeter. It shows 0.535V in forward bias direction.
I thought also to check its current i.e when meter is used to check diode drop. So I connected ammeter in between:
New Vdrop= 0.568 (total across diode & ammeter)
I = 337.2 uA.
Help me to understand this & why diode drop is not 0.7V at low current, Diode forward voltage drop
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