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Dec19-12, 03:42 PM
P: 8
Dear forum

I have s issue concerning rectification of a sinusoidal voltage with a diode. It is a experiment i am doing.
The case is a 1N4001 diode in series with a lamp and a capacitor in parallel to the lamp. The circuit is supplied by a sinusoidal voltage with a rms value of 2.2 V.
The set up can be seen on the attached file called "Half_wave_rectifier". (The switch is open so the diode does not get bypassed).
On the attached file called "HalfWaveV_L" is 3 graphs showing the voltages of the lamp. The yellow is with zero capacitance and the orange and red is with the capacitances drscriped at the figure.

My first question is why the wave has higher peak values with capacitors than without a capacitor? To that comes why the wavetops for the yellow graph is apruptly cut of, compared to the round tops of the orange and the red graph.

I have also measured the rms current in the circuit for the various capacitances, and it gets bigger the bigger the capacitance is. I cant understand why that really is. The peak values of the voltage increases with the capacitance, so that kind of explains it, but then again, why does the peak values grow?

The rms currents meassured was 0.26 A for the yellow graph, 0.4 A for the orange graph and 0.41A for the red graph.

I understand that a capacitor in parallel works as a energystorage which can supply the system with voltage when the voltage of the power supply gets low.

I hope you can help, that this is the right place for my post.
Attached Thumbnails
Half_wave_rectifier.png   HalfWaveV_L.jpg  
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