Test circuit

178

02:29:31

Why is current shown flowing in both directions with a diode?

published 6 years ago

PrathikP

6 years ago

It is because you have set the frequency to 60khz (which is 60000hz) for some reason. At that frequency, an ordinary diode craps out. And diodes have some junction capacitance. It is tiny, but at such a high frequency, it can let an AC current flow.

PrathikP

6 years ago

Just for clarification, the mains voltage in north america is 120V 60Hz and not 60kHz.

PrathikP

6 years ago

And your load should be parallel to the capacitor, not series, assuming you intend to power the lamp using rectified mains

tonyinselby

6 years ago

And the 120V figure is RMS. Peak or amplitude is 120√2, or about 170V.

zdrux

6 years ago

Thanks for pointing out the frequency, I have changed it to 60Hz now. The circuit seems to be behaving as expected now. But am I to believe there are no circuits out there that have a capacitor after a diode in series? Since no current can cross the capacitor, and there is no return path for the current due to the diode, this circuit is essentially useless?

zdrux

6 years ago

Also, how are electrons getting through the light bulb if no electrons can pass through the capacitor in my circuit?

rich11292000

6 years ago

Once the capacitor charges all the way up the current won't flow anymore

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