Voltage Balancing: Capacitive vs Resistive

[KyleGranger]

TL;DR Summary

Is there a rule of thumb when to use each one?

I know this is a loaded question because there are many situations. Are you trying to implement voltage balancing on a switching node, DC bus, etc. Is there a general rule of thumb that I can use for when to use capacitive vs resistive voltage balancing. Can I use a string of "tiny" capacitors for voltage balancing on a DC bus? Losses should be reduced with capacitive are my thoughts. I'm just wondering some of the tradeoffs and if there's a rule of thumb when to use each...or even a combination of both.

 

[sophiecentaur]

Summary:: Is there a rule of thumb when to use each one?

Can I use a string of "tiny" capacitors for voltage balancing on a DC bus?

The admittance of a Capacitor to DC is zero so are you discussing the effect during transitions? To eliminate ringing on transitions could involve some complicated filtering which would depend on load impedances.
It may need to be done actively.

 

[KyleGranger]

The admittance of a Capacitor to DC is zero so are you discussing the effect during transitions? To eliminate ringing on transitions could involve some complicated filtering which would depend on load impedances.
It may need to be done actively.

Yes so the admittance of capacitors to DC is zero. Is there a rule of thumb when you would want a such a voltage divider? Especially compared to a resistive voltage divider. I did a search on the topic but didn't find much. I'm sure the knowledge has to be out there so thought I'd ask it here.

 

[Baluncore]

I'm sure the knowledge has to be out there so thought I'd ask it here.

Yes it is, but we are not mind readers and there are too many interpretations of your wide question, that seems to involve some previous thread.
Are you balancing series voltage dividers, or balancing currents between equal parallel voltage sources?
Efficient switching systems employ capacitance and inductance. Without inductance, switch resistance becomes a heat source.

 

[KyleGranger]

Yes it is, but we are not mind readers and there are too many interpretations of your wide question, that seems to involve some previous thread.
Are you balancing series voltage dividers, or balancing currents between equal parallel voltage sources?
Efficient switching systems employ capacitance and inductance. Without inductance, switch resistance becomes a heat source.

I'm not involving any previous threads. I'm just hoping to get some discussion in general.

Your question were if I'm balancing series voltage dividers or currents. That's the type of thing that I'm wondering...capacitors shouldn't be used if XX or they're better for XX. My default is resistors but I know using capacitors are possible too. I figure that I just need to control the power dissipated through the resistors but I'm wondering if there's a better way of looking at it. Most of my current applications are balancing voltages, but that doesn't mean that will be my only application.

 

[Baluncore]

Most of my current applications are balancing voltages, but that doesn't mean that will be my only application.

It takes a lifetime to acquire wisdom. I don't have sufficient time left in my life to list all the possible cases and exceptions that you may be considering.

Please give us one or more example circuits that you need to balance.
Then at least we will know if the voltages are in series or in parallel.

Once you refine your question, a finite answer may become possible.

 

[Tom.G]

I'm not involving any previous threads. I'm just hoping to get some discussion in general.

Your question were if I'm balancing series voltage dividers or currents. That's the type of thing that I'm wondering...capacitors shouldn't be used if XX or they're better for XX. My default is resistors but I know using capacitors are possible too. I figure that I just need to control the power dissipated through the resistors but I'm wondering if there's a better way of looking at it. Most of my current applications are balancing voltages, but that doesn't mean that will be my only application.

Capacitors won't do anything at all for balancing DC, they are an open circuit once they charge to the DC voltage. You will have to use resistors for that situation.

For AC, you can usually use either resistors or capacitors; but there are some situations where one may be preferred over the other.

The above is the most general answer to your general question. If you have a specific application in mind please say so, we may be able to come up with more applicable details.

Cheers,
Tom

 

[sophiecentaur]

Yes so the admittance of capacitors to DC is zero. Is there a rule of thumb when you would want a such a voltage divider? Especially compared to a resistive voltage divider. I did a search on the topic but didn't find much. I'm sure the knowledge has to be out there so thought I'd ask it here.

I am now very confused about what you actually want.A Resistive Voltage Divider is a very elementary circuit. Are you saying you can't find any information on that?
What exactly do you mean by the term "voltage balancing" in the original post? Do you mean some form of filtering to reduce switching products?
When you use the word "node", do you mean 'mode'?