Voltage Regulator with Capacitive Divider

[stanford]

To supply a voltage line, it seems like using two capacitors as voltage divider is a good idea. It removes noise, no power is dissipated, voltage level depends on the RATIO of two capacitors. Why don't we use capacitive divider for voltage regulators?

 

[jiripolivka]

To supply a voltage line, it seems like using two capacitors as voltage divider is a good idea. It removes noise, no power is dissipated, voltage level depends on the RATIO of two capacitors. Why don't we use capacitive divider for voltage regulators?

Voltage regulators are used for DC circuits. Do you know that capacitors do not affect DC current?

Capacitor dividers are used in AC circuits only.

 

[stanford]

And we don't use resistor dividers because they burn power right?

 

[BradtheRad]

Is this the kind of voltage dividing capacitors you mean?

I devised step-down stacked capacitors, with a bit of effort at the simulator.

35 or 40% of original supply V is a typical amount to expect (after diode drops, etc).



Notice the large number of parts needed to accomplish this.

The capacitors are charged by current spikes, which carry disproportionately great I*I*R losses, reducing efficiency.

 

[zzllearner]

would you please tell me what simulation software did you use above?

 

[BradtheRad]

This is Falstad's animated interactive simulator. Free to download and use at:

www.falstad.com/circuit

Your computer will need Java installed (if it isn't already).

 

[zzllearner]

Thank you for your generous answer.

 

[dick_freebird]

A capacitive divider only works (properly) when clocked,
zeroed periodically. This does consume power. Less than
a low impedance resistor divider most likely, but nonzero
and needing complexity. If you clock the feedback you
can expect to see noise from that (deterministic tones
in the output; customer must deal). You also will likely
need a high voltage capacitor - got one? - and switches
(ditto). And to make sure the switches and the driven
load do not mess up your ratio.