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High(er) Current Buck Converter Options


raven1152
(@raven1152)
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I'm looking for an alternative to the LM2596 Buck Converter module used in the "Build a Simple Power Supply" episode.

The rating for the LM2596 based converter that I purchased is 3 amps, with a heat-sink that ironically was not provided and 2 amps without a heat-sink.

The problem, i think, is that the laptop power supply that I am using for my 19.5V DC source is rated at 6.5 amps.  I also purchased a variable voltage buck converter (the one with the display) that is capable of up to 10 amps of current.  With the much lower amp rating on the smaller LM2596 based buck converter I'm concerned that I might burn it up without even realizing how much current I'm drawing.

Is this really a problem?  I think the laptop power supply used in the video was at least 5 amps.

This topic was modified 1 year ago by raven1152

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triform
(@triform)
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Hi @raven1152,

When I did the build of my PSU with the DP30 module, I did it the opposite way.  I wanted a typical bench PSU voltage/wattage range and no more than 3 amps.  I chose a OSKJ (or 05KJ, not sure) boost converter.  It is a 150w (nominal) and has a 35v output max. It's fairly efficient and can put out @ 3amps with little problem powering from a 19v laptop brick. With good wires and a fan, you could possibly get 5 amps from it, but I myself would not run 5 amps from a DP30. I think 3 amps is a safe and stable power out for it.  Anything past that, I would look for other options.

Are building a bench PSU or a dedicated one for some project?

Scott

 

 


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raven1152
(@raven1152)
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Posted by: @triform

Are building a bench PSU or a dedicated one for some project?

This will just be a general purpose power supply, but I want to be able to run some dc motors off of it on the bench for testing. Nothing too large, but maybe something that could draw an amp or two, with maybe a stall current of 3 or 4 amps?

I think it might help if I list what I am using...

For my adjustable voltage connection: https://www.amazon.com/dp/B0744BT79M/ref=cm_sw_em_r_mt_dp_U_20vXEb0XZ1426

For my fixed voltage connection: https://www.amazon.com/dp/B06XRN7NFQ/ref=cm_sw_em_r_mt_dp_U_JXvXEb6199VTR  

The fixed voltage unit is the one I'm worried about overloading.

This post was modified 1 year ago by raven1152

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triform
(@triform)
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Joined: 2 years ago
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@raven1152

If it's just a bench PSU, then you just want to remember not to do "stupid PSU tricks" 😉  We all do that though 🙂

If you put a heatsink on the buck and have a fan in the case, you should be ok at 2-3amps on it.  I would run a fuse just over or at your chosen max power out.  You could also fuse bucks input and or output at your chosen max for it as well. 


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triform
(@triform)
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Joined: 2 years ago
Posts: 339
 

@raven1152

BTW, if you are in the USA, there is a good deal to be had on a NEW Meanwell PSU in closeouts. Let me know and I can send the info to you.


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