Title: "MegaLoad" V2.0
Post by: barcher174 on September 07, 2015, 11:06:41 PM
Post by: barcher174 on September 07, 2015, 11:06:41 PM
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.
--
Brian
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.
--
Brian
Title: "MegaLoad" V2.0
Post by: barcher174 on September 08, 2015, 12:58:52 AM
Post by: barcher174 on September 08, 2015, 12:58:52 AM
And I guess as a logical next step:
Everything contained in the soundbox.
--
Brian
Everything contained in the soundbox.
--
Brian
Title: "MegaLoad" V2.0
Post by: barcher174 on September 08, 2015, 11:45:15 PM
Post by: barcher174 on September 08, 2015, 11:45:15 PM
It seems there are issues getting this to work across different power supplies. Not sure yet what is causing it.
Title: "MegaLoad" V2.0
Post by: barcher174 on September 09, 2015, 01:33:32 AM
Post by: barcher174 on September 09, 2015, 01:33:32 AM
It looks like there is some variance in the minimum load. I will need some smaller resistors to get a lower series resistance.
Title: "MegaLoad" V2.0
Post by: degs on September 12, 2015, 02:53:09 AM
Post by: degs on September 12, 2015, 02:53:09 AM
Quote from: "barcher174"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?
Title: "MegaLoad" V2.0
Post by: barcher174 on September 12, 2015, 05:24:13 PM
Post by: barcher174 on September 12, 2015, 05:24:13 PM
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.
Title: "MegaLoad" V2.0
Post by: degs on September 12, 2015, 06:12:23 PM
Post by: degs on September 12, 2015, 06:12:23 PM
Quote from: "barcher174"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.