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Arlo Power Distribution Board - is this what you asked for? — Parallax Forums

Arlo Power Distribution Board - is this what you asked for?

Ken GraceyKen Gracey Posts: 7,389
edited 2015-06-03 11:24 in Robotics
Hey there,

A while back several customers asked for a clean power management system on the Arlo.

One of our forumistas (Phil Pilgrim) designed it quickly for us.

Details are here http://www.parallax.com/news/2014-03-28/arlo-power-distribution-board-arlo-robotic-platform-system-heading-kitting

Please leave us a comment on that page after you take a look.

Ken Gracey
«134

Comments

  • Roy ElthamRoy Eltham Posts: 3,000
    edited 2014-03-28 14:33
    This is excellent! Very nice work Phil!

    I'll be wanting two of these when they are available. One for my Arlo, and one to upgrade my older MadeUSA setup.
  • Ken GraceyKen Gracey Posts: 7,389
    edited 2014-03-28 17:24
    Roy Eltham wrote: »
    This is excellent! Very nice work Phil!

    I'll be wanting two of these when they are available. One for my Arlo, and one to upgrade my older MadeUSA setup.

    Seems John Abhsier is happy with the design, too. I can't tell you how much easier this board makes it to wire an Arlo.

    We'll be sure to set you up when they're in stock (please remind me).

    Ken Gracey
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-03-28 17:30
    I like this concept. Maybe you could expand and make these for other platforms also, including the Wild Thumper. I may buy one and attempt to retrofit on my WT.
  • NikosGNikosG Posts: 705
    edited 2014-03-29 14:04
    Extremely useful accessory for a large robot!!!!!!
    I wish I had one before design the Artist robot .
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-03-29 18:00
    @Phil Pilgrim, any chance of getting a schematic for this board? I have been wanting to make a PDB for some time now and I really like your design. http://forums.parallax.com/showthread.php/122225-Power-Distribution-Board?highlight=power+distribution
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-03-29 19:13
    I've sent an email to Ken to see if it's okay and will post the schematic if he says yes.

    -Phil
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-03-29 19:22
    Great. Thanks. My intention is not to copy the idea, just to breadboard something similar to make a proto type until these ones are available. If not it is no big deal. I have waited this long and can wait a couple months longer for their release. I know I will need at least a couple to start.
  • Ken GraceyKen Gracey Posts: 7,389
    edited 2014-03-29 19:30
    NWCCTV wrote: »
    Great. Thanks. My intention is not to copy the idea, just to breadboard something similar to make a proto type until these ones are available. If not it is no big deal. I have waited this long and can wait a couple months longer for their release. I know I will need at least a couple to start.

    You can copy it and sell it as your own if you wanted to. There are no restrictions on our designs - guess you could say they were open source before it was fashionable. We haven't posted the files but we will in due course.

    Ken Gracey
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-03-29 20:13
    Thanks Ken. I am looking forward to the release of this as I am quite sure Phil has done a much better job than I ever could.
  • jdoleckijdolecki Posts: 726
    edited 2014-03-29 20:17
    Mabee a kit form were we can solder it ourselves. Or sell bare boards.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-03-29 21:37
    Attached is the schematic. (Thanks, Ken!)

    -Phil
    pdf
    pdf
    arlo_pwr_dist_RevA.pdf
    13K
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-03-29 21:41
    Thank you sir!
  • SRLMSRLM Posts: 5,045
    edited 2014-03-29 22:38
    Out of curiosity, why did you use the V7806-2000 switching regulator rather than going directly to 5v with the V7805-2000 regulator? Is that so that systems that already have a 5v regulator can be powered off a lower source than the ~12v of the battery?

    The labeling might be a little bit misleading if there's no mention in the documentation. The AUX 12v is battery 12v, not regulated 12v. And the AUX6.5 has a 2amp fuse, along with the 1A 5v fuse, is more than the 2A maximum current rating of the V7806-2000 regulator. So that's something for users to be careful of.

    Also, another question: what is the diode for? It doesn't seem like it would help with reverse polarity protection, and if it's being used to drop the battery 12v down than isn't it reducing the overall efficiency of the design, negating some of the switching regulator benefit?

    I like the arc design for the screw terminals: that seems like something that would help prevent wires from getting in the way of each other.

    Have you considered adding holes for other standard battery connectors? I'm thinking mostly of Deans Plugs and XT60 connectors.

    It might also be interesting to make a version that has a buck/boost switching regulator for 12v for systems that require that. You could use the same board and have the regulated 12v be an "upgrade" (since the parts would probably be pretty expensive).

    I like the switches and the acrylic cover. That's a nice touch.

    Anyway, this board directly addresses one of the most annoying issues in robotics: breaking out the power.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-03-29 23:12
    SRLM wrote:
    Out of curiosity, why did you use the V7806-2000 switching regulator rather than going directly to 5v with the V7805-2000 regulator? Is that so that systems that already have a 5v regulator can be powered off a lower source than the ~12v of the battery?
    Cost. The objective was to have two output voltages: an output greater than 5V for servos, and 5V. Two DC-DCs would have been prohibitively expensive. And running the '2940 directly from 12V would have led to thermal issues.
    And the AUX6.5 has a 2amp fuse, along with the 1A 5v fuse, is more than the 2A maximum current rating of the V7806-2000 regulator. So that's something for users to be careful of.
    That's a current topic of discussion. After the proto boards arrived, I realized that I could have run the '2940 from the 6.5V fuse, rather than directly from the DC-DC. But, truth be known, the DC-DC is fully short-circuit and overcurrent protected, so the fuse on the 6.5V output is somewhat superfluous anyway. 'Still, it's something that's not too late to change.
    Also, another question: what is the diode for? It doesn't seem like it would help with reverse polarity protection, and if it's being used to drop the battery 12v down than isn't it reducing the overall efficiency of the design, negating some of the switching regulator benefit?
    The diode is there to isolate the 1000uF cap from back-discharging during transients on the 12V supply and causing 6.5V and 5V brownouts.
    Have you considered adding holes for other standard battery connectors?
    No.
    I like the arc design for the screw terminals ... I like the switches and the acrylic cover. That's a nice touch.
    You can thank Matt Gilliland, Daniel Harris, and Ken for these features and for the overall concept. I just laid out the board from Matt's DXF drawing showing the board outline and general parts placement.

    -Phil
  • SRLMSRLM Posts: 5,045
    edited 2014-03-29 23:41
    I volunteer with a FRC robotics team, and one problem that we had this year was brownouts. Each robot has a 24v wireless router, and on occasion the router on the robot would reset during a match. As it turns out this was due to voltage drop. We're running 4 big CIM motors for the 4 wheels, and when the stall current got high enough the motors would drop the SLA battery voltage down to below 10v (from a freshly charged ~13v). This caused problems in the router power circuit.

    Anyway, probably not as big of an issue with motors that aren't as highly rated as the CIMs, but it's something that caught us all off guard.
  • PublisonPublison Posts: 12,366
    edited 2014-03-30 03:21
    The schematic was hiding in picture #7 in the link in Ken's first post. :)
  • SRLMSRLM Posts: 5,045
    edited 2014-03-30 06:44
    Publison wrote: »
    The schematic was hiding in picture #7 in the link in Ken's first post. :)

    You're right! I didn't even notice that the carousel had more images. The arrow blended in with all the noise of the ARLO that was behind it. Perhaps Parallax could make the arrow have a background, and also appear in the popup.

    right-arrow-icon
  • WhitWhit Posts: 4,191
    edited 2014-04-24 19:15
    Any further word on this item?
  • Ken GraceyKen Gracey Posts: 7,389
    edited 2014-04-24 19:33
    Whit wrote: »
    Any further word on this item?

    Happy Birthday, Whit!

    We found a mistake on the PCB and had to order a second run. Bottom line up front: June 1st, for certain.

    Ken Gracey
  • WhitWhit Posts: 4,191
    edited 2014-04-25 13:36
    Thanks Ken! And thanks...
  • rogersydrogersyd Posts: 223
    edited 2014-06-08 05:51
    UGH im so impatient! Take my money now parallax!
  • ChrisL8ChrisL8 Posts: 129
    edited 2014-06-11 08:55
    Yes, this is exactly what I want!
    I actually have a diagram for an Arlo power distribution system on my dry erase board right now which only serves to convince me that I do not really want to build one myself. I've been stalling for months on building an Arlo because of the power distribution system issue.

    I think if you can price it just under $100 it will be well worth it to those of us who don't build electronic projects on a routine basis.
    The saved time and money in designing the system and then buying all the little pieces and soldering them together is huge. Not to mention the peace of mind knowing some real engineers made the decisions and tested it ahead of me.

    Also, it is beautiful. Those of us not good with the drilling and cutting stuff and without laser cutters are very grateful for custom PCBs and acrylic plates!
  • ChrisL8ChrisL8 Posts: 129
    edited 2014-06-11 09:01
    Will the 5V line have enough amps to power a Raspberry Pi?
  • PublisonPublison Posts: 12,366
    edited 2014-06-11 09:16
    clofland wrote: »
    Will the 5V line have enough amps to power a Raspberry Pi?

    The Regulator will supply 1 AMP. Should be sufficient for a RPi. You would need to consider other 5 Volt devices also using the same power source.
    .
  • ChrisL8ChrisL8 Posts: 129
    edited 2014-06-16 15:01
    What charger should we use with this? Or will it include one?
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2014-06-17 13:52
    What charger should we use with this? Or will it include one?

    Hi clofland - Welcome to the Forums :-)

    The charger isn't on our website yet, but it should be in stock - it's #700-00240. I think it's about $50.

    However, you could use any standard 12 SLA battery charger, and if you wanted to use it with this new Power Distribution Board, it would need a center positive 2.5mm x 5.5mm OD jack, to fit into the receptacle.

    -MattG
  • Matt GillilandMatt Gilliland Posts: 1,406
    edited 2014-06-17 13:56
    Also, it is beautiful.

    Yep it is kinda cute ;-) - you should see it in real-life!

    I'm working on the documentation now and I'll let you know when it's available "RSN".
    -MattG
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-06-17 15:56
    Price???????
  • WhitWhit Posts: 4,191
    edited 2014-06-17 18:49
    @NWCCTV - all they've said so far is "less than $100"
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-06-17 19:54
    all they've said so far is "less than $100"
    I'd say that is a pretty wide spectrum!!! Any release date yet?
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