Variable Power Supply

Jorge Feliu

Prodigy 80 points

Other Parts Discussed in Thread: LM337, LM117, LM317A, LM317

Hi, I need for a mini-lab experiment a Variable Power source in volts and ampers.

The input volt will be AC 220 volts.

The Output must be CC 0 to 20 Volts VARIABLE

The current must be 0 to 20 Amp VARIABLE

I have found some circuitry on the web, but some has bad comments, so I came to the experts for solution.

Thanks in advance.

Jorge Feliu

over 12 years ago

0 John Bottrill over 12 years ago

TI__Mastermind 25130 points

Jorge,

This is not something that the forum normally answers. This sounds like you are looking for a lab supply. There are many out there.

Do a search on GOOGLE for lab power supplies and you should get lots of options.

Regards,

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

Thanks John:

That was exactly what I do first, but the ones I read seems to have some problems, so I not like to waste my time with it. Then I prefer to ask the guys how really knows.

Regards.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

I can endore any supplier of power converters, power analyzers or loads.

regards,

John

0 John Bottrill over 12 years ago in reply to John Bottrill

TI__Mastermind 25130 points

Jorge,

That should have read -

I cannot endore any supplier of power converters, power analyzers or loads.

Regards,

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

Thanks again John. But, as a member of Texas Instrument you can recommend me some products of TI where I can make the board that I am looking for.

I have the LM117 and LM337 technical data, but it seems that these are very few ampere capability, so I think that probably TI has the right one, but I cannot find it.

¿Can you give me some ideas to sart to look at?

Regards.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

If I knew of any TI products that would meet your requirements I would have already provided you with the names and data sheets on them.

Regards,

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

Waiting for your news, I remain.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

Send me your corporate E-mail address.

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

My EMail is jorge-feliu@hotmail.com or you can reach me at joranfel@gmail.com

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

John:

I just returned from a 500 mile trip so now I see your Email.

Thanks for your help.

But I still can not find what I am looking for.

In page #19 of Catalog Texas Instrument

.................................LM117/LM317A/LM317 3-Terminal Adjustable Regulator Catalog..............

You can see a diagram to construct a Regulator with variable Voltage and Variable Current. But not for my needs.

I am looking for 0-20Volt and 0-20Ampere.

Thanks.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

You are talking about using a series regulator form 220 V AC ( 312 V peak) to generate a 0 to 20 volt 0 to 20 amp supply.

You are looking at dissipating better than 6 kW.

I don't think I can help you.

Regards,

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

John: I will use a TD in the input to convert 220 Vac to 35 - 50 Vac (0.5 - 1.0 kW)

Max charge will be 20 Vcc 20 Amp = 400 Watt = 0.4 kW

So I think you can help me.

If your product LM117 and LM317A has a circuitry for this pourpose, so probably you have another LM¿xxx? to fulfill my needs.

Sorry if I annoy you with my request.

Regards.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

Series regulators are not an area I cover.

That said you have to calculate the losses in the series regulator worse case. Assume you are supplying 20 amps at 1 volt from your 50 volt AC.

That would be 70 volts at 20 amps across a 3 terminal series regulator or 1400 Watts.

As I said I can't help you.

Regards,

John

0 Jorge Feliu over 12 years ago in reply to John Bottrill

Prodigy 80 points

Ok John, thanks a lot for your help.

¿Can you suggest were I can find it?

Regards.

Jorge Feliu

0 John Bottrill over 12 years ago in reply to Jorge Feliu

TI__Mastermind 25130 points

Jorge,

No idea or I would already pointed you in that direction. If you are designing a product at those power levels you are probably going to have to meet requirements that will force you to include Power Factor Correction.

Regards,

John

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