Basic RC circuit question

Submitted by nora on

Hi. I'm new to electronics, hence the basic question.

When a load such as a lamp is placed in parallel with a capacitor in a basic RC circuit, why doesn't current flow through the lamp while the capacitor is charging? The virtual simulator i am using shows no current through the lamp until the capacitor is fully charged. Why wouldn't there be some current divided between both the capacitor branch and the lamp, and then just the lamp when the capacitor is fully charged?

Thanks for your help.

You need to provide the schematic. Is the lamp acting as the R in RC circuit? Parallel RC circuit or the lamp is in parallel of series RC circuit?

Virtual simulator provides output based on ideal state of the comonent. In real life the thing is different.

  Joined February 12, 2018      696
Monday at 02:11 PM

The capacitor affects the rise time. Too see this in a simulator you must use pulses.

I would show you a capture from the simulator but I see no way to upload an image in this basic forum.

  Joined February 15, 2021      5
Monday at 11:34 PM

Capacitor has low ESR resistance than the lamp. Providing images would be beneficial. Use the IMCE button in the toolbar to upload images.

Thank you.

  Joined February 12, 2018      696
Monday at 02:11 PM

I can't see the imce button on mobile, but just to add, I'm using an led and not a lamp. Not sure if that changes anything? I can see it takes about 40ms for the led branch to get to 1.8v and then the current flows, whereas the parallel capacitor branch current flows the instant the switch is closed. I will upload an image when I get back on my work computer. Thanks for all your help.

  Joined February 20, 2021      1
Saturday at 11:57 PM

Well, Capacitor has very low resitance called as ESR than the diode.

  Joined February 12, 2018      696
Monday at 02:11 PM