Recommend 300v regulator circuit

[garry2004]

Hi All:
My application requires regulated 300vdc at about 150 mils. I have a DC/DC converter that will handle the load, but now I need a good regulator circuit.

Any ideas?

Thanks in advance for any help you can offer.
Garry
(garry@jetcoder.com)

 

[flatulent]

300v regulator

You are into the area that can cause bodily injury so be careful when you work with this supply. One trick is to string enough zeners to make 280 V and power them from your supply through the usual resistor. Then put in a three terminal regulator using this 280 V point as the 'ground' for it. This only works when the input varies over 15 V or so.

 

[nicleo]

300v input regulator

Hi All:
My application requires regulated 300vdc at about 150 mils. I have a DC/DC converter that will handle the load, but now I need a good regulator circuit.

What has '150 mils' to do with regulated 300vdc?
What is the input range?

 

[VSWR]

Re: 300v Regulator

I think the poster means "150 milliamps" (i.e. 150 milliamperes = 0.15 A).

 

[IanP]

Re: 300v Regulator

First to moderator: 3-pin voltage regulators are not good ideas in HV applications...

Attached are couple of ideas how to regulate HV.
Do use only transistors rated abov Vmax (400+).
Example of main power transistor: BU326, BU426, MJE18006 ...

 

[cozturk]

300v Regulator

3-pin voltage regulators are GOOD ideas also in HV applications. But you'll not connect IC's gnd to real gnd. For example if you use 7812, you can regulate 320V to 300v. Of course a resistor or zener(s) needed for 7812gnd to real gnd. Voltage should be 288V at 7812's gnd.

 

[IanP]

Re: 300v Regulator

Coztruk,

3-pin voltage regulators are designed to operate (in most cases) up to 40Vdc and above this voltage they will be "killed".
How are you going to protect this device against voltages over their rating values (output short-circuit)???
The protection circuit will be more complex than the regulator itself...

 

[cozturk]

300v Regulator

The IC works only about 15vdc input. so it can regulate the output. Voltage between IC's gnd and IC's input ≤20vdc.

For output short-circuit protection, a resistor for 7812's input will be enogh. for example if we need only 300v/5mA. Put 470nF and 470ohm serises to 220V 50HZ mains (before diode bridge and elco), This is only for short-circuit protection, no over voltage protection seems. Some series zeners may be useful to output and gnd. more complex?

Note: This is not theoretical circuit only. 100% tested. I saw on a electronics magazine.

 

[IanP]

Re: 300v Regulator

Cozturk,

Article in a magazine does not prove anythig.

Using low-voltage components in high-voltage circuits is not good practice.
I am not telling you that if everything is in order this circuit will not work..my point is that if something goes wrong (Murphy's laws apply here...) everything will be burned!!!

 

[ME]

300v Regulator

Here's a 300 Vdc voltage regulator:
**broken link removed**
**broken link removed**