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Subject: 
Re: Solar-powered RCX?
Newsgroups: 
lugnet.robotics
Date: 
Tue, 10 Nov 1998 18:42:47 GMT
Viewed: 
2430 times
  
Kekoa Proudfoot wrote in message <199811101742.JAA03702@pixel.Stanford.EDU>...
Sorry, maybe there is to much engineer in me but are you saying the
external power supply produces low voltage AC and that it is rectified in
the brick to DC to run the system? I can believe it's regulated inside,
but it needs DC from the "wall wart", not AC.

I believe AC is okay, although most wall warts are DC.  Look at the little
9-12 V ~ symbol right near the port :)



This implies a 9-12V AC adapter. This is a cost reduction, since a DC adapter
is generally a transformer, bridge and minimal filtering.

The Brick needs reverse voltage protection anyways, so why not move the bridge
from the wallwart to the brick?!

The CPU needs a regulated supply, which can be got from the lumpy 9-12. I'll
wager that if you measure the output of the motor port at high load full on
you will see some AC ripple in the order of a volt or two?

ARRGGH. I have all the tools to do this and no Mindstorm!

Cheers,

Ralph Hempel - P.Eng

------------------------------------------------------
The train stops at the train station,
The bus stops at the bus station,
So why am I sitting at a work station?
------------------------------------------------------
Reply to:      rhempel at bmts dot com
------------------------------------------------------



Message has 1 Reply:
  Re: Solar-powered RCX?
 
I use a big transformer only type wall wart I had laying around. Pure AC output. The wall wart says it is 9VAC @ 3.2A but no load is about 10.5VAC. I'm sure this is more power than I need but it was free. If I look at the normally (battery) 8.2vDC (...) (26 years ago, 10-Nov-98, to lugnet.robotics)

Message is in Reply To:
  Re: Solar-powered RCX?
 
(...) I believe AC is okay, although most wall warts are DC. Look at the little 9-12 V ~ symbol right near the port :) -Kekoa (26 years ago, 10-Nov-98, to lugnet.robotics)

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