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Electronics / Re: Electric bicycle
« Last post by Schlayer on April 06, 2015, 04:44:22 PM »
Well... The max stall current should definitely be less than 220 Amps, yes. I highly doubt the continuous drain would be over 110A also, but those number seems extremely high for a MOSFET at that price. If its true to its datasheet, that should indeed work. I don;t know a ton about transistors, but if I were you I'd make sure you have a fuse between the positive lead of your battery and whatever circuitry you have in that pot/controller circuit. You'll want one that will trigger at 200A like this:
My concerns about the MOSFET are mainly due to its size. You see that fuse has 2 gauge wire on it. 2! That's gigantic. Considerably smaller would melt under the heat of 100-200A of current. I'm really unsure how a MOSFET with such tiny pins could handle 110A continuous, but you are right that in all likelihood the motor draws well under that. I guess you may as well go for it and test it, but make sure you trigger it from a distance in case the MOSFET explodes!  I'll talk to a friend who is more familiar with MOSFETs and get back to you.
Electronics / Re: Electric bicycle
« Last post by newbie_teach on April 06, 2015, 03:47:23 PM »
Frankly I never debate/argue with pro engineers/makers who have a ton of knowledge than me. But let me take a chance and clear this concept in my mind. I "need" to know the stall current you said,can't we make assumptions? How much can be the max stall current? Not more than 220A right? Just use a MOSFET IRF3205 has a drain current of 110A continuous and 220A burst VDS of 55v. Isn't that enough? By your potentiometer/rheostat method do u mean to power it up directly? No way that will be done. Your correct.
Basically a small potentiometer will be wired up with an arduino and just like the fade sketch where pot controls the LED's brightness instead of led there will be that motor driver circuit (no h bridge since only one direction is required).
Please correct me where I am wrong. I like being corrected.
Thank you for bearing and helping me :)
Misc / National Robotics Week at ServoCity!
« Last post by ServoCity on April 06, 2015, 12:55:57 PM »

We are excited about National Robotics Week and you should be too! There are all kinds of cool events happening across the states April 4th - 12th; be sure to check out the NRW site for events near you. Here at ServoCity, we’ll be celebrating all week with a variety of fun promotions, sales, tech tips, new product launches and more! So you don’t miss out on any of the week’s activities, we’ve provided the calendar of events below. We look forward to celebrating all things robotics with you! Be sure to like us on Facebook, follow us on Twitter, and subscribe to our e-mails!

To see a full calendar of events please visit!
Electronics / Re: Counting the pins
« Last post by Schlayer on April 06, 2015, 11:06:10 AM »
To figure out how to translate that display to an Arduino you'd need detailed spec sheets for that part saying what signals go to which pins, and match those to their analogs on the Arduino LCD display. I'm inclined to say it's possible, in theory, but in practice I have no idea how you might go about it... Sorry.
Electronics / Re: Can a stray Polystyrene strip cause static on a Motherboard?
« Last post by Schlayer on April 06, 2015, 11:01:00 AM »
It's certainly possible that somehow a bit of packaging material got inside the case. There are a lot of reasons when you buy a motherboard (I needed to replace one in my own desktop recently) they come in antistatic bags. Lots of PC parts companies won't accept returned items without them being packaged just-so, often requiring an antistatic bag among other things. It's completely possible that static might have arose from the shifting of packing peanuts during transit, and any kind of static charge can in the worst cases wreck something like a motherboard. This is why antistatic wristbands are recommended when handling such components. There are many reports of the static from wearing socks on a carpeted floor ruining a PC builder's day! I'd say you have every reason to complain to Apple about that being the fault of poor shipping/handling practices which were obviously out of your control. I hope you have some luck getting that resolved!
Electronics / Re: Counting the pins
« Last post by ThaAnarchist on April 06, 2015, 09:36:06 AM »
Thanks a bunch. That is the connector that I am looking for but is it possible to use it on an arduino board? All the tutorials I have seen are simply using Arduino LCD's.
Misc / HGR Industrial Surplus – Used Industrial Robots/Parts
« Last post by PTD on April 06, 2015, 08:11:08 AM »
We currently have in stock over 100 robotic items, from full industrial robots to parts, controllers, etc. that members of the forum may find useful.  You may follow this link for additional information:
Electronics / Re: Counting the pins
« Last post by bdeuell on April 06, 2015, 06:33:15 AM »
those are some blurry pictures...anyway

when trying to identify a connector i typically try the following:
- looking for any numbers or markings on the connector and google them
- count the number of pins (usually specd by the total number), count on both the plug and receptacle to double check
- measure the connector pitch
- search by the product and connector description

I simply searched "nintendo ds p3 connector" and got several hits (please confirm that you are looking for the P3 connector i made this assumption based on other pictures i saw). Here is an ebay listing that claims to be the P3 connector
Misc / Re: Analyzing the Axon series: Coding, Contruction, and Contraptions
« Last post by mklrobo on April 06, 2015, 05:23:34 AM »
Axon series: What is this thing?
Got the Project Designer to work; opened up the projects, could not find any,
so started a new one. Voila!  ;D a pretty picture of the board comes up in the
right frame of my screen. As I select any pin on the left, in a spreadsheet type
format, the associated pin that was selected blinks on the picture on the right.
(so I know which pin I am using, I think) There are several variables next to
the spreadsheet pin selection, and I guess, they are avaliable features for
that particular pin.( ??? ) Could not generate any code; do not know how to use this
at this time. working on it....  8)
Mechanics and Construction / Re: have you used Nachi 8600-A
« Last post by mklrobo on April 06, 2015, 05:15:08 AM »
Will try to help, if I can.
Your description;
Error 3: in IC Memories, Error 22: encoder LED is wrong and Error 155: This robot(or controller) type number is not registerd.
Back in the day, When I assembled computer boards by hand (Looong time ago!), when we did the
benchmark tests, as Error like the error 3   :-\ might pop up. Experience in those problems revealed
loose ICs' in the sockets, bad Ics', or (worse case   :'( ) traces that had been destroyed or improperly
made at the factory.  I would hazard a guess, that the other errors may be caused by the memory
problem; reason being, that if the computer (MCU) can not access memory, it might have problems
accessing devices.(such as the encoder). Depending on the schematic and programming, troubleshooting for
your model does not seem impossible, but will consume time/labor.
Troubleshooting the memory;
Each chip(for memory), if removeable, can be tested individually, or just replaced. Check out the sockets, if any, or
solder joints. Bad solder joints will have a ring aroung the soldered pin, and will not seem as shiny as
other pins. If they all seem that way, get some fish and chips, because it will be a job to resolder all the
pins.(shotgun effect) Bad solder joints can drop .5 volts,  :o which is enough to destroy a digital signal.  :'(
I would not recommend changing the ROM (if any) or MCU at this time. Those hardly ever fail.
I will try to dig up some more info if I can. Keep me posted..... ;D ;D ;D

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