Powering the YBox from another source
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Powering the YBox from another source

by telarium on Fri Aug 05, 2011 2:01 am

This is more of a general electronics question, but I'm a bit new to all of this, so maybe someone can help.

I'm hoping to power my Ybox2 off the same power as a small, black and white TV. I've taken the TV apart to do some other wiring, so I figured I could connect the positive and negative to the connections on the board of the TV and connect them to the Ybox2.

The TV is powered with a 12v power supply, which I know is too much for the Ybox. I created a small board with a 5v regulator. The power from the TV's power is soldered input connection, and I had the output soldered to a connection to the power plug on the Ybox2.

But the YBox2 won't turn on. I noticed the voltage on the regulator BEFORE I connect the YBox2 is around 5v, but after I connect the YBox2 to the output of the regulator, the voltage drops too low.

Anyone have any suggestions of how I can go about this? Or if it's even possible? I'm going to have to add a Wifi bridge at some point, so I'd rather not have this thing running off three different power adapters.
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Re: Powering the YBox from another source

by adafruit_support_bill on Fri Aug 05, 2011 5:50 am

but after I connect the YBox2 to the output of the regulator, the voltage drops too low.

Sounds like your regulator board is not able to supply enough current. The YBox needs between 5v & 9v at 300 mA.
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Re: Powering the YBox from another source

by telarium on Fri Aug 05, 2011 10:31 am

One thing that confuses my new-to-electronics brain. When connecting the TV's 12v power to the input pin on the regulator, the output pin shows 5v. Perfect. Then when I connect the Ybox2 to the output in, the voltage drops significantly. I'm not understanding why this is so.

Any recommendation on which kind of regulator I should? I'm currently using the +5V Fixed-Voltage 7805 from Radio Shack.

http://www.radioshack.com/product/index ... =107597886

Also, can you recommend the best pins on the YBox2 to solder the power connections? Should I just solder them to the joints underneath where the power connection usually goes?
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Re: Powering the YBox from another source

by adafruit_support_bill on Fri Aug 05, 2011 10:50 am

when I connect the Ybox2 to the output in, the voltage drops significantly. I'm not understanding why this is so.

It is because the Y-Box needs as much as 300mA and your regulator is unable to supply that much current. The 7805 itself should be able to handle that much, so it is probably a limitation of the 12v supply that is feeding it. If it can't supply enough current, the voltage will drop.

Should I just solder them to the joints underneath where the power connection usually goes?

That will work. Just be sure to get the polarity correct.
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Re: Powering the YBox from another source

by telarium on Mon Aug 08, 2011 12:24 am

Another questions. Is it not advisable to directly solder the RCA jack from the Ybox2 to the board on the TV? Or does that introduce too much interference?
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Re: Powering the YBox from another source

by adafruit on Mon Aug 08, 2011 5:32 pm

you can but really, an RCA cable will work fantastically and they're very common!
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