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 Robotics / Handy Board / 5143
5142  |  5144
Subject: 
RE: RESEND--Re: Help with Power Scheme, Please...
Newsgroups: 
lugnet.robotics.handyboard
Date: 
Fri, 15 Jan 1999 22:00:50 GMT
Original-From: 
"Graham, J. Todd" <grahamjt@Maritz.com>
Viewed: 
791 times
  
In the example, are there any advantages or disadvantages in using a voltage
regulator (such as a 7805) to dropping the voltage from 12v to 5v as opposed
to using a diode string?

Also, I guess no one had an answer on the earlier question of running the HB
in a continuous-power mode (ie from a wall-wart).  I would be intersted in
knowing an answer to this as well if anyone has an idea.  If the HB was
constantly doing something (or at some frequency, I assume the trickle
charge mode would be good to keep the battery going.  But, I can't imagine
it would be good for the unit to sit on the charger idle for days at a time.


Todd

-----Original Message-----
From: Will Bain [mailto:willbain@cs.umt.edu]
Sent: Friday, January 15, 1999 2:19 PM
To: Handyboard Mailing List
Subject: RESEND--Re: Help with Power Scheme, Please...


I apologize for having sent the following with extra line-feeds in it;
Here it is again:

The main problem I see is with how you label the voltages at various
points in the circuit.  If you have a 12 V battery, the low voltage end
is usually called zero volts and the high voltage end is called +12
volts (although the numbers are just relative to each other).  You show
-12 V at one end and +12 V at the other, which you could only get with a
24 V source (which wouldn't be appropriate).  Perhaps the following
would make more sense:


                                        +12V            +---------------+
           +--------------------------------------------|  Handy Board
+------+
           |                                            +----+-----+----+
|
           |  +---------------------+   + 9V                 |     |
|
    +------+--|     Diode String    |----------------+       |     |
|
    |      |  +---------------------+                |     + |     |-
|
    | +    |  +---------------------+   + 5V         |  +----+-----+----+
|
+---+---+  +--|     Diode String    |--------------+ |  | R/C DC Motors |
|
|  12V  |     +---------------------+              | |  +---------------+
|
|Battery|                                          | |
|
|  04A  |                                          | |  +---------------+
|
+---+---+                                          | +--| Video  Camera
|------+
    |                                              | |  +---------------+
|
    |                                     0V       | |  +---------------+
|
    +------+-----------------------------------+   | +--| Video  Transm
|------+
    |                                          |   |    +---------------+
|
  -----                                        |   |    +---------------+
|
   ---  Ground                                 |   +----|  R/C  Servos
|------+
    -                                          |        +---------------+
|

+-------------------------------+
                                          , ,
        __@_/             \_@__           |/
          |                /__,           o             @_/
          )\              )              ( \            (\/\\,
~~~~~~~~~ ' ` ~~~~~~~~~~~ ` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Wendy Parson,             The fellow who agrees with everything you say
Will Bain,                      is either a fool or he is getting ready
& Tatoosh                                   to skin you.  --Kin Hubbard



Message has 1 Reply:
  Continuous charging
 
Graham, J. Todd wrote: <snip> (...) If you use zap charge mode, you'll end up cooking your batteries unless the HB draws just the right amount of current. If you use any motors or other high current devices connected to the HB, trickle charge mode (...) (26 years ago, 16-Jan-99, to lugnet.robotics.handyboard)

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