solar tracking using LM339

Discussion in 'The Projects Forum' started by greenJames, May 8, 2013.

  1. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Ok this is going to be my new home for my solar tracker made with the circuit from greenwatts LM339



    After some deliberation I have decided to build my circuit on a bread board first and the move on to a pcb cut on my CNC router

    First question I have in this circuit diagram we have the LM339 with a black dot with in the component (fig 1 Am I right in thinking this is pin one.

    fig 1

    [​IMG]

    If this is correct how do I find pin one on the component

    fig 2

    [​IMG]

    I should rename this post solar tracker for dummy's he he

    thank you james
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
  3. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Thank you for the post and the link

    James
     
  4. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Well Today I did start to TRY and make my circuit on the breadboard from circuit diagram and the pcb layout but I got very confused with Jumper wires go here and there this being connected to this and that being connected to this. so after about two hours I pulled everything out and turned my attention to drawing the PCB board

    I also found it hard to read the colour's on the resistors so diverted to using my multimeter! much better idea and I even found a good link for the math part http://www.hobby-hour.com/electronics/resistorcalculator.php

    has any one got any tips on making a breadboard circuit from a circuit diagram

    I've nearly finish drawing my circuit ready for cutting out.

    [​IMG]
    the above image is not to scale

    I do have other question regarding the LM339 chip and it's relationship with the circuit diagram but I will ask those questions later on in my project.

    Head spinning stuff this electronic and circuit building.

    James
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    That's a bad move. You really need to be very comfortable with your circuit on the breadboard before moving to the PCB. Even the pros will experience problems at that step, moving from breadboard to PCB. Solving the problem often requires a step back to the working breadboard circuit to tweak a resistor here or a capacitor there. Skipping the breadboard altogether makes it more likely you will build a nonfunctional PCB, i.e. a paperweight.

    IF you are strictly copying the PCB from a well-documented project, so that you don't really need to understand it so much as build it, I might be persuaded to skip the breadboard step. But most of the time it is invaluable. I don't think many here will say they regret time spent breadboarding before building.
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    I use a well-lit work area and a magnifying glass to speed up this chore. It's SO much easier.
     
  7. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    You may get a lot of comments on this, as I suppose everyone is different.

    For a small circuit like this, build it up around the "main" IC, in this case your LM339. Power connections come first, positive on top and negative below (assuming your breadboard is horizontal). Inputs to the left and outputs to the right. Leave plenty of room initially, condense it later if you need to. Remember that the numbered breadboard rows are interconnected on either side of the central valley. Leave the board unpowered until you've triple-checked things, and be prepared to disconnect quickly if something smokes! ;)

    Oh, and if the drawing gets complicated it helps to check off the interconnects as you reproduce them on the breadboard.
     
  8. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Ok I've started my breadboard AGAIN, I'm sure I will have many questions along the way but my primarily question is why is their two 12v power supplies (two 12v battery's).

    Hear is the link to the circuit diagram
    http://solartracker.greenwatts.info/solar_tracker_LM339_schematic.htm

    Can I split one battery with two positive and negative connections

    This may be a silly question but please remember I called my self greenJames for a reason
    James
     
  9. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    It's a way to get two directions from the same motor. Another - and more common - way is an H-bridge motor controller. It's a slightly more complex circuit but would eliminate the need for 2 batteries. It's widely used for robotics and and all sorts of DIY projects, so you'll have no trouble finding lots of information on it.
     
  10. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    so how would i add this to the circuit I'm building
    or should i be looking at a different circuit altogether ?

    James
     
  11. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    I can't comment on your second question, but you could keep the left hand side of the circuit and replace the right-hand side motor control with an H-bridge. The outputs of your comparator would drive the H-bridge instead of the darlington transistor arrangement shown there now.
     
  12. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Thank you wayneh I will build it first and then start playing around with different circuits I think as I have another solar tracker I want to build for the main tracker (this one is just for my 12 year old son) The other tracker uses arduino but I have yet to find the coding to make it work

    here is the link http://www.kokoras.com/solartracker/en/

    GreenJames
     
  13. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,985
    745
  14. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    so now I curious can this circuit be used as a stand alone solar tracker if not would some one explain how I integrate this into the LM339 circuit

    I've bought two 12v battery's today 12V-2.1Ah General purpose lead acid battery which I'm looking at a solar panel to charge it

    James
     
  15. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,985
    745
    Yes its a stand alone tracker, it wont work with the LM339 as it needs a collector load resistor, try an LM358

    http://www.electro-tech-online.com/members/kevinng-albums-op-amp-comparator-picture55793-2.jpg
     
    Last edited: May 10, 2013
  16. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Ok so I've taken the plunge and down loaded the eagle software I tried Designspark but found the library limited

    Now I've nearly finish the PCB but I cant find two items in the part library

    LM1458
    and a symbol for a motor

    Is there anyone that could help me

    James
     
  17. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Morning all well I've just about finished my drawing but I really do need some help on three Items first two are related to the schematic I have done.

    First I cant work out how to add a motor (work load) to my drawing and secondly I have two errors I cant solve please see images below

    [​IMG]

    [​IMG]



    I have spent most of the morning drawing this circuit plus eagle crashed once so I have to draw it again from scratch stupid me. Yes the wife is saying your spending to much time on that computer!!

    I have now included the drawing for help and advice

    GreenJames
     
    Last edited: May 12, 2013
  18. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,985
    745
    Looking at your drawing you have no motor just a short circuit link, is that one of the faults?
     
  19. greenJames

    Thread Starter Member

    Apr 24, 2013
    68
    3
    Yes Dodgy I cant work out how to get a motor from the Library (cant find it any where)

    but more to the point I cant work out the power connection conflict on the LM1458

    as you say it may have some thing to do with no load on the circuit

    James
     
  20. wayneh

    Expert

    Sep 9, 2010
    12,118
    3,043
    You could just use a lightbulb or low ohms resistor to stand in for the motor for now.

    It may be complaining that you're using the LM1458 with a single supply, so that the negative rail is at 0V instead of, say, -12V. You could try putting +6 on top and -6 below, to see if that is it.
     
Loading...