- #1
valeriy2222
- 14
- 0
Hi.
I've been studying in details how a microphone works. I've found a type of microphones where capacitor is used to record sound. The idea is simple. Increasing and decreasing the distance between the plates of a capacitor (sound waves) results in the changing capacitance. Being connected to DC (direct current) power supply, it creates oscillating current which is then recorded. There is a detail which is not well explained.
The charging current.
If a capacitor is connected to DC power supply, the current flows (from + to -) building a charge on the plates and after some time the capacitor voltage become equal to power supply voltage. After that, if we decrease the distance between the plates of the capacitor, the current will start flowing again (from + to -) thus continue building the charge. No problem with understanding.
The discharging current?
When we increase the distance between the plates, the charge on the plates wants to go back to the power supply. This time it wants to go from + to +. Here, I do not fully understand whether it's really going back (but where it can go otherwise?) or not. Does it override the voltage of the power supply? A battery instead of spending energy begins to be recharged?
Electrons on one of the plates have to leave it but the only way to go is the power supply - "+ to +", "- to -".
[PLAIN]http://www.ustudy.in/sites/default/files/images/condenser%20microphone.jpg
I've been studying in details how a microphone works. I've found a type of microphones where capacitor is used to record sound. The idea is simple. Increasing and decreasing the distance between the plates of a capacitor (sound waves) results in the changing capacitance. Being connected to DC (direct current) power supply, it creates oscillating current which is then recorded. There is a detail which is not well explained.
The charging current.
If a capacitor is connected to DC power supply, the current flows (from + to -) building a charge on the plates and after some time the capacitor voltage become equal to power supply voltage. After that, if we decrease the distance between the plates of the capacitor, the current will start flowing again (from + to -) thus continue building the charge. No problem with understanding.
The discharging current?
When we increase the distance between the plates, the charge on the plates wants to go back to the power supply. This time it wants to go from + to +. Here, I do not fully understand whether it's really going back (but where it can go otherwise?) or not. Does it override the voltage of the power supply? A battery instead of spending energy begins to be recharged?
Electrons on one of the plates have to leave it but the only way to go is the power supply - "+ to +", "- to -".
[PLAIN]http://www.ustudy.in/sites/default/files/images/condenser%20microphone.jpg
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