How to make a continuity tester

I have two multimeters; one which gives a reading but no audible beep when the contacts are made, and the other multimeter which is broken but works for continuity testing, however doesn't always beep if the level it reads isn't quite high enough.

I wanted something more reliable!

A continuity tester is a gadget that literally tests "continuity" or continuence, in other words, you use one to check where traces lead to on printed circuit boards.

There are several guides on YouTube and Instructables, however they all seem to use 3v battery (as run an LED to show when continuity is present) or more, if move voltage, then they use a resistor to stop the LED from frying. Ok, 3v is probably ok for most work, however if you are prodding about with finding traces on microchips, it isn't always a good idea to have 3v running through parts of a board.

My method is different because it only uses 1.5v to achieve a similar result; less voltage = safer for a motherboard. 

The result I think looks quite professional, a light on one of the ends of the gadget illuminates, at a place you are looking at anyway (ie the tip); and made using the following:

2 x pens
1 x light from a GameBoy light unit
Some thick single core wire (for the probes)
Black electrical tape
1 x AAA battery
About 60cm of flexible wire

Scissors
Soldering iron and solder
Flux (so you can solder to the battery terminals)
Glue / hot glue

Step 1 The pens

What pens you use are entirely down to what you have available; what you want are clear ones so when the light is installed, you will see it shining. Most disposible pens seem to be almost exactly the same circumference as an AAA battery, which is handy.

Step one: find two similar pens

Step two: disassemble

The looks of the pens you use may look different, however most have a screwable tip and end

 

Comments

[MODDEDbyBACTERIA]

Use probes instead of the metal ends.

[kylerock96]

how would i make this with probes from a multimeter?