600v to 3.3v voltage regulator

[kekek]

hi,
does anyone know how to bring down 600vdc with current approximately 6.667A to 3vdc, 5mA beside using a resistor network? is there is any voltage regulator that can come down the voltage of 600vdc to 3vdc?

 

[Oznog]

Ouch!

Well, burning the power up with resistors would mean at least 3 watts for a 15mW output. You won't find a regulator rated for anything like 600V on the input. In any case, a simple 3V regulator may need 3 mA just to idle, so efficiency gets worse. Maybe a 3V zener and a 120k resistor would work ok.

There are ways to do a far more efficient dc/dc converter, but you won't be able to make it work without a complicated bootstrapping system (there's no voltage to run the converter's logic until the converter's running).

Maybe a resistor is the best solution, but what are you trying to do? Is extremely poor regulation, no surge capability, and poor efficiency ok?

 

[zachtheterrible]

what in the world are you geting 600 volts from??

 

[John Sorensen]

The DC link on an 480VAC inverter runs about 600-700VDC. I don't know if that's what he's doing, but it's not exactly rare. Now, why you would want to do that, that's a different question!

j.

 

[moutouloss]

:shock: :shock: :shock: :shock:

 

[pzajac]

You seem to be having the same issue I'm having with high voltage DC. I'm trying to step down the voltage from 600VDC to at least 30VDC and I'm not finding an easy solution. My application has to do with solar panels that can supply up to 600VDC when arrays are strung together and I'm trying to develop a monitoring system and want to tap off of the existing voltage available in the box to power my circuit. I don't think you will find a regulator that will drop the voltage down to that level and I'm having difficulty finding a DC to DC converter that will do this without spending a boatload of money.

 

[Styx]

need SMPS in both cases (600-->30V & 600-->3.3V).

flyback converter.
I got a 600Vdc link converter at work and at the moment we are using a external 28V supply to supply the converter control. We want to incorporate a PSU within the converter based around a similar design we used for a 270Vdc converter... but 600V is a bit different

The plan we have is to have a crude fixed duty step-down converter to take the 600V downto something more managable (say... 300V) and then use one of our present PSU designs to control the new rail more accuratly

with the 3v3 case you will need another step-down to take 30V to 3v3

 

[seveprim]

why not tap it off the first battery in the bank grab 12 volts there (i am assuming it is 12 volts in series of about 50 other batteries...

grab a dc to dc converter 9 to 18 volts in, 5 volt out and put a 3.3 volt regulator ... the output will be isolated from the orginal battery via a dc-dc module ... you can 1 watt ones and the like some old ethernet card have them too incase ya try and get one in hurry!

 

[kchriste]

why not tap it off the first battery in the bank grab 12 volts there (i am assuming it is 12 volts in series of about 50 other batteries...

This is really bad practice. It will result in the unbalancing of the charge across the battery string; though at 5ma vs 6.7A it may not be much of an issue in this case.
The OP really needs to tell us what the source of the 600V is before we can give valid advice. If it comes from a switching regulator, you could add a coil to the transformer to tap at a lower voltage, etc.

 

[seveprim]

This is really bad practice. It will result in the unbalancing of the charge across the battery string; though at 5ma vs 6.7A it may not be much of an issue in this case.
The OP really needs to tell us what the source of the 600V is before we can give valid advice. If it comes from a switching regulator, you could add a coil to the transformer to tap at a lower voltage, etc.

I think you have no idea how leaky batteries are (self discharge rates can be as high as 20%per month on lead acid/gel) Besides they should not be charged in series that would be more prone to failure each battery should be charged individually. But lets do the maths.

(6700 milliamp hours(100%)- 5milliamphours) = 6695milliamp

Percentage loss on cell in terms of capacity = 6695/6700= 99.92 percent. Now considering most lead acid system rarely charge to 100% ie they cut out at 14.4v and most do not factor in temperature of cell which also affect capacity ...

So in short I think your comment is hog wash considering things like self discharge rates, losses in connections, and system will never call 100% of the battery capacity (otherwise going to be replacing alot lead acid cells) I think it can stand to lose 0.08 percent on one cell to acheive the goal !

 

[seveprim]

No DC-DC chips accept 600v input. Maybe you can design a DC-DC circuit with high voltage MOSFET. But I prefer the resistor solution, after all the output is only 5ma.

Mike

Please do not answer my ideas with stupidity if you read correctly I said to tap of 12 volts from the first battery ! READ READ READ !

 

[seveprim]

I haven't read your answer at all. I was answer the first post.I'm not interested in your idea and won't read it.

Well if you read my post you would understand how a DC -DC could solve the problem ! Instead be ignorant as it just proves to me you know nothing !

 

[kchriste]

Besides they should not be charged in series that would be more prone to failure each battery should be charged individually.

Ahem.... All 12v lead acid batteries are actually 6 2V cells in series. This is what an equalization charge cycle is for.

So in short I think your comment is hog wash considering things like self discharge rates, losses in connections, and system will never call 100% of the battery capacity (otherwise going to be replacing alot lead acid cells) I think it can stand to lose 0.08 percent on one cell to acheive the goal !

Maybe YOU should read my posts more carefully:

It will result in the unbalancing of the charge across the battery string; though at 5ma vs 6.7A it may not be much of an issue in this case.

Besides, the OP never mentioned batteries in this thread anyways. I stand by my original post; tapping a battery string is bad practice. Think about this scenario: what happens if the bottom battery in the string goes open or is disconnected? Voila, -588 volts where there was once 12V!!!!

 

[seveprim]

Quote:
It will result in the unbalancing of the charge across the battery string;

Sorry I just dont agree with this statement

They all charge and discharge at the same rate under normal use (12v /6 cells)in one battery until failure sets in. Which in almost all cases be resulting from a sulfide build up.


5 milli amp is not going to affect 6.7 amp cells. I be more worried about current drain from the actual device that is going be powered by the 600v volt set. Out of 50 batteries there is going to be more then .08% difference in capacity hence the lowest capacity in the group will be the first to suffer, besides if ya read back. I stated the 12volt cells should be charged individually and not in a series setup.

 

[Super_voip]

What do you do with the 600V from the solar panels, is it powering something or just going thru some converter to sell back to the grid?

 

[kchriste]

besides if ya read back. I stated the 12volt cells should be charged individually and not in a series setup.

What I meant was that ALL 12V lead acid batteries are made up of six 2Volt cells. Hence the cells are in series and are charged/dsicharged in series. Whether you have two 6V batteries in series or just one 12V battery, it is still six 2Volt cells in series!

It will result in the unbalancing of the charge across the battery string;
Sorry I just dont agree with this statement

It will if the current drawn off the tap point is large enough. It will result in the bottom battery being under charged and the remaining being over charged; resulting in excessive gassing of the top batteries in the string and sulfating of the bottom one.

 

[Styx]

what was the original question again?

 

[deja_wu]

hey ı need 0 - 10 mv voltage source
but ı cant regule so lowww
if any one can help
find me deja_wu99@ h or priv mes to me
thanks a lot !!

 

[Hero999]

Perhaps a 400V three phase switching regulator would do the job, assuming such a beast exists with a 3.3V output, if it doesn't I'm sure you can get 400VAC to 48V converters, then all you need to do is add a 3.3V switching regulator on the output. There again a three phase 48V supply is likely to be rated for >3kW so it's a bit overkill.

EDIT:
deja_wu,
Please create a new thread rather than derailing this one.

 

[Styx]

exactly what I said last page... goto an intermediate rail first. you can get ACDC converters that are rated at a few 10's of watt's