Power supply design

Rodney Jackson

Hi, I am trying to build a power supply for my laptop computer. It is 19V at around 6A. I purchased another unit from China that was rated at 8A but failed in less than 24 hours. I used my bench supply to finish the project I was working on, no problems and had set current limit to 7A, it never missed a beat and did not trip the supply. I now wish to build a 19V at 10A supply and have trouble following the T.I. design tool. Does anyone have the circuit for the required power supply? Would be quite nice to get started and free up the bench supply for its intended purpose.

Thanks all.

Rod.

over 8 years ago

0 Nikhil Gupta (Product Folder Models) over 8 years ago

TI__Mastermind 39210 points

Rodney,

So you want something at 19V @ 10A. What is your input voltage range?

Thanks,

0 Rodney Jackson over 8 years ago in reply to Nikhil Gupta (Product Folder Models)

Prodigy 60 points

Hello Nikhil,

thank you for your reply to my query.

I have 2 options, I have a torriod transformer that has 2 x 15V windings. I could use them in parallel to give 15V @ 20A this should give me about 22V DC into a regulator circuit, if this is not enough to work with then I could series connect them for 30V at 10A and get around 42V DC

I am not too sure what the regulator might handle on a minimum voltage, or what maximum voltage it is rated at.

Sorry I forgot to mention this in my original message.

Rodney Jackson.

0 Nikhil Gupta (Product Folder Models) over 8 years ago in reply to Rodney Jackson

TI__Mastermind 39210 points

Rodney,

At such a high output voltage and current, a controller would be most appropriate. I entered both your specs into the WEBENCH Power Designer and was able to get over 20 solutions from TI in both cases.

1. Vin min = Vin max = 22V, Vout = 19V @ 10A >> Found 30 solutions

2. Vin min = Vin max = 42V, Vout = 19V @ 10A >> Found 22 solutions

Please give it a try here.

With such a wide variety of solutions to choose from, you can use "Advanced Options" to narrow down the requirements for your power supply from within WEBENCH.

Let me know if that helps.

Thanks,

0 Nikhil Gupta (Product Folder Models) over 8 years ago in reply to Nikhil Gupta (Product Folder Models)

TI__Mastermind 39210 points

Rodney,

If possible try to go for the 2nd option of using 42Vin. In the other case, you will be operating close to 100% duty cycle mode and any variation (drop) in Vin may cause Vout to go out of regulation.

Thanks,

0 Rodney Jackson over 8 years ago

Prodigy 60 points

Thanks again Nikhil for your help here. I certainly will give the 42V option a go since I only require 10A Max. out.

Now I only have to get the hang of the WEBENCH program, which I will now that I know there are definite solutions available.

Regards,

Rodney Jackson.

0 Nikhil Gupta (Product Folder Models) over 8 years ago in reply to Rodney Jackson

TI__Mastermind 39210 points

Rodney,

We have a lot of training material available to get you ramped up on WEBENCH. You can find instructions here:

Also, if you want to go through video tutorials, they are also available here

In addition, we are available on the E2E forum to answer any questions you might have.

Best regards,

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Power supply design