LM386

Discussion in 'The Projects Forum' started by frenchie29, Dec 6, 2008.

  1. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    I am using a LM386 for a project I want to change the slider switch for a 12v rocker switch with LED built in


    http://www.wiringproducts.com/index...get=d35.html&gclid=CNK6kbKkrZcCFRJexwodiWSyig


    How do I wire it to the pcb? Where is the ground on the LM386 for the on/off switch??I did a continuity test and and the rocker switch doesn't break the circuit I still have tone even when the switch is on the off position.
     
  2. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    Also I'd like to know where is the is the return? I want to use a 9v battery I found the positive lead but can't find the negative. Here's the kit I am using.

    http://www.kitsrus.com/pdf/k17.pdf
     
  3. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    The negative is the ground pin.
     
  4. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    Why do you want to change the switch and make mess on the board?

    Which one do you want to use?
     
  5. Wendy

    Moderator

    Mar 24, 2008
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    I always like the datasheet myself.

    Leave the circuit as is, just leave the slide switch on. Wire the rocker switch in line with the power supply. I'm not sure how the light in the rocker switch is wired, you might be able to remove the LED and wire the switch LED in place.
     
    Last edited: Dec 7, 2008
  6. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    I want to use it in a project box so I can actually use the amp and the switch that comes with it is rectangular and cannot cut it out plus it's way too small here's the switch that I want to use. http://www.nfauto.co.uk/images/feb2007/mini_rocker_led.jpg It has a + , A , GROUND symbols on the body for the 3 leads. What does the A means? I would assume that the + gets connected to the positive pole of the 9v and the ground to the ground of the kit, but not sure about the A lead.


    Do you know how to wire it to that kit??? There's 3 really small holes in the PCB top is OFF and bottom is ON with a white square that covers the 2 bottom holes.
     
  7. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    I believe it's the lead with the A on it

    I will try (where it says ON on the PCB) to the + of the switch- the other ON position to the A (which I think is the LED in the switch) and the OFF position to the ground of the switch. Is that make sense???

    BTW what is the best way to solder wire to a PCB??? I went from underneath by putting the point of the iron on both the pad and the wire itself and putting solder all the way around (got that from youtube videos) but the top where the drawing is, all the connectors have no strain-relief and are all getting loose and wobbly.

    Just as a FYI I am taking an online electronic course and learning electronics with small projects as I take my course.
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    Use the holes, they offer better strain relief. Pay special attention how the LED in the switch is wired vs. the one in the schematic.
     
  9. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    Should I put some solder on the top as well ? The wire goes trough the hole and sticks out at the bottom (with solder) but the top is not solid at all. I could see the wire breaking off easily.
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    You have to handle any board with wires coming off with some delicacy, this is pretty much true of everything in this class. The real problem is rigidity, if you put too much solder into the wire it can't flex, so it will break. You DON'T want solder anchoring the wire too tightly, just enough for good electrical contact. Try not to flex the wires excessively. Plan what you are going to do, then do it with a minimum of fuss. Oh yeah, use stranded wire too.

    Wire is designed to flex, just not back and forth many times.
     
  11. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    Is there a product that would cover the joints and re-inforced them? Like silicone? It will sit in an ABS plastic box but probably will be bang around a bit.
     
  12. Wendy

    Moderator

    Mar 24, 2008
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    Just mount the board, it can be with 2 sided foam tape. Is this going to be in a rugged environment like a car?
     
  13. frenchie29

    Thread Starter Active Member

    Nov 28, 2008
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    No for work I do audio for broadcast TV I have a Q box but want to build my own so I can really understand what's in the box.
     
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