Simple Polarity Tester

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Introduction: Simple Polarity Tester

In this instructable I will show you how to make a simple polarity tester capable of out to about 12vdc.

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Step 1: Materials

-4 diode (must at least withstand 12vdc)
-1 red LED
-1 green LED
-1 1k ohm resistor
-perf board
-solder
-soldering iron

Step 2: How to Know How to Position Diode on Circuit Board

You should notice a white, Grey or other color banned on your diode, this is were it goes on a schematic.

Step 3: The Circuit

-D1=Green LED
-D2=Red LED
-D4 to 7=Diode
-R1=1 k ohm resistor

Step 4: Now Your Done!

Now that your done you can use it for any circuit testing under 12vdc.

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    22 Discussions

    0
    GitarGr8
    GitarGr8

    12 years ago on Introduction

    Cool idea, this is a great project for a beginner. I don't think that D4 through D7 are needed in this case because you are using LEDs, which are themselves a type of diode. Try building a circuit like this:

    06 2008-03-23.jpg
    0
    camaney
    camaney

    Reply 9 years ago on Introduction

    I need to check the polarity on batteries of 2V, 6V, 8V and 12V will this simple design will work as well or do I have to implement a switch and add different resistances value?

    0
    GitarGr8
    GitarGr8

    Reply 9 years ago on Introduction

    You'd probably want a different resistor for the various voltages and LEDs, but I don't see why this wouldn't work for what you're trying to do. you might want to add a selector switch for the different voltages you are trying to test, each with the properly sized resistor for that voltage.

    0
    agis68
    agis68

    Reply 10 years ago on Introduction

     Yeah right LEDs are diodes. So we don't need the diode. BUT we need them if we have a non stable charger (PSU)...now we replace the diodes by Zeners . For example if you work with 4,5 V the need a 5v1 zener. Zener protects and reduce the Voltage but no the Amps.

    0
    Dr.Bill
    Dr.Bill

    Reply 11 years ago on Introduction

    this works good to 12v. or so with a 47 ohm resistor.

    0
    Ben The Builder
    Ben The Builder

    Reply 11 years ago on Introduction

    That's what I was thinking, you don't need more diodes you only need the two

    0
    steven123654
    steven123654

    Reply 10 years ago on Introduction

    1n4001 if I remember right but it doesn't really matter.

    0
    GorillazMiko
    GorillazMiko

    12 years ago on Introduction

    Cool, but you really want to use macro mode on your camera. It's a little flower icon-- it helps a lot.

    0
    steven123654
    steven123654

    Reply 12 years ago on Introduction

    I don't think I have it it's a really cheap camera.

    0
    computerwiz_222

    This is essentially a fancy lighting up multimeter. This is actually a really great idea! I can't tell you how many times I will be working in my car and I want to check polarity of some wires or something.

    0
    BrianKT
    BrianKT

    12 years ago on Introduction

    Try using macro mode on your camera next time you take pictures that close up. Btw, why do the pictures say they're from 2004? Great concept though.

    0
    Kiteman
    Kiteman

    Reply 12 years ago on Introduction

    It's either an old idea, or his camera's clock is set wrong.

    0
    Kiteman
    Kiteman

    Reply 12 years ago on Introduction

    (I'd guess the latter, since he apparently made the whole thing at twenty past midnight as well.)

    0
    lawizeg
    lawizeg

    Reply 12 years ago on Introduction

    i don't want to sound stupid...but what's polarity?

    0
    Kiteman
    Kiteman

    Reply 12 years ago on Introduction

    It's which way round the current flows (the + and - on batteries). Also, some components, like diodes (including LEDs) and some kinds of capacitor, only work when the current flows through them one and not the other.