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"MegaLoad" V2.0

 
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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Mon Sep 07, 2015 9:06 pm    Post subject: "MegaLoad" V2.0 Reply with quote

I spent some time perfecting the load boards for use with 152 power supplies. Here is the newest version:

http://imgur.com/gallery/7cwHb9U

People -really- don't seem to like the bulb, so the trick is to burn off power as heat without melting anything. I'm using 6 banks of 5 39ohm 2W resistors in parallel. Making for a total of ~47ohm in series. I was aiming for 56ohm but ran out of room. With the current configuration they are warm to the touch but not so hot you can't keep your finger on them. Should be easy enough to recreate for anyone interested.

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Brian
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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Mon Sep 07, 2015 10:58 pm    Post subject: Reply with quote

And I guess as a logical next step:



Everything contained in the soundbox.

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Brian
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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Tue Sep 08, 2015 9:45 pm    Post subject: Reply with quote

It seems there are issues getting this to work across different power supplies. Not sure yet what is causing it.
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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Tue Sep 08, 2015 11:33 pm    Post subject: Reply with quote

It looks like there is some variance in the minimum load. I will need some smaller resistors to get a lower series resistance.
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degs



Joined: 21 Sep 2006
Posts: 34
Location: Conway, NH

PostPosted: Sat Sep 12, 2015 12:53 am    Post subject: Reply with quote

barcher174 wrote:
It looks like there is some variance in the minimum load. I will need some smaller resistors to get a lower series resistance.

Have you considered using a power mosfet and a variable resistor across the gate?

What do you need this load for anyway?
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barcher174



Joined: 07 Dec 2012
Posts: 560

PostPosted: Sat Sep 12, 2015 3:24 pm    Post subject: Reply with quote

The load is for 152 power supplies to be used without the Megapixel monitor attached. My issue with a power mosfet is the heat generated. I have limited room for a heatsink. I need to pass ~400ma through it.
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degs



Joined: 21 Sep 2006
Posts: 34
Location: Conway, NH

PostPosted: Sat Sep 12, 2015 4:12 pm    Post subject: Reply with quote

barcher174 wrote:
The load is for 152 power supplies to be used without the Megapixel monitor attached. My issue with a power mosfet is the heat generated. I have limited room for a heatsink. I need to pass ~400ma through it.


Ah, I see. Well, the heat density of a mosfet will be higher, but it will take less space than your resistors. You can run that current without a heat sink at 5V, but I don't know your voltage requirements. I generally put heat sinks on my devices at 3W or so.

Pretty neat project.
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