## Friday, October 20, 2023

555 IC Continuity Tester: Diode, LED, and Wire Checker

Looking to simplify your electronics testing? In this step-by-step YouTube tutorial, we've got you covered with a homemade Continuity Tester using the versatile 555 IC timer. Whether you're a beginner or a seasoned pro, this project is perfect for anyone!

What you'll learn in this video:

How to assemble a simple and affordable Continuity Tester circuit.

Testing diodes, LEDs, and wires for conductivity and functionality. Understanding the indicator LED and buzzer signals for quick and easy diagnostics.

Practical applications and troubleshooting tips for your electronics projects.

Don't miss this opportunity to upgrade your electronics toolkit and your diagnostics streamline. Hit that "Like" button, subscribe for more fantastic DIY projects, and let's get started on this informative journey!

Hi, i wanted to have a continuity tester (my multimeter doesn't have a buzzer) so i don´t have to look away from the circuit I am testing to see the multimeters display. Although i wanted a buzzer i also added a LED and an on/off switch for late night tinkering "stealth mode"

I don´t have any engineering or electronics background (actually i am a surgeon), but i love to make stuff and i am self teaching electronics with the help from Google and instructables.com. This is my first instructable and English isn´t my native tongue, so bear with me please...

DISCLAIMER: If following this guide anything/anyone/yourself damages i shall not be held responsible.Do it at your own risk. Take all the safety measures (goggles, gloves, etc)

-Highlighter (worn out)

-Pen

-Blue LED

-switch

-555 IC

-0.01uF ceramic capacitors= 2

-1uF electrolitic capacitor = 1

-180 k resistor = 1

-56k resistor= 1 (i did it on the weekend with no stores opened, so i used 47k + 10k series resistors)

-Piezo buzzer= 1 (i used a Hycom HY-07 that i took from an old modem)

-Button cell batteries= 3

-Battery holder (from a cheap pen/flashlight I had)

-Wires

-Soldering Iron

-hot glue gun

-xacto knife

First of all, I took apart the highlighter, threw away the tip and the ink cartridge by cutting the back end with an xacto knife. And I did the same to the flashlight/pen in order to take the battery holder away.

I found a buzzer circuit ( http://electronic-circuits-diagrams.com/alarmsimages/alarmsckt5.shtml ) the easiest and simple circuit I could find and tried it on the breadboard. It worked out fine, except I changed the 10k resistor (pins 7 and 8 of the 555 IC) for a 180k resistor because I liked the tone better.

i soldered all together over the 555 directly trying to make it as compact as possible (although i had plenty of room inside the highlighter, i did that way just in case i want to house it in a smaller pen someday)

-I stuffed some solder with the wires into a BIC pen tip (it´s a little messy because of the ink) and heated them with the soldering iron. -Then wired the tip to the (-) leg of the led and the pin 1 of the 555 IC.

-The (+) leg of the LED and the pin 4 of the 555 (through the on/off switch) to the positive pole of the battery pack.

-The secondary probe (another used pen) with a wire wrapped around the tip to the negative pole of the battery pack

When the two probe tips touch each other (or through a conductive material such as a wire or a circuit track) the circuit closes and the LED lights up and the buzzer vibrates with a nice tone.

The buzzer can be turned off with the switch, while the LED still lights up with continuity.

-I made a hole on one side of the highlighter so I could install the small switch I had

The buzzer and the battery holder are housed in the cap that clips on the end (that was reattached with a hole so wires can pass through and hot-glued). This allows me to change the batteries when they die.

555 IC Continuity Tester: Diode, LED, and Wire Checker

Looking to simplify your electronics testing? In this step-by-step YouTube tutorial, we've got you covered with a homemade Continuity Tester using the versatile 555 IC timer. Whether you're a beginner or a seasoned pro, this project is perfect for anyone!

What you'll learn in this video:

How to assemble a simple and affordable Continuity Tester circuit.

Testing diodes, LEDs, and wires for conductivity and functionality. Understanding the indicator LED and buzzer signals for quick and easy diagnostics.

Practical applications and troubleshooting tips for your electronics projects.

Don't miss this opportunity to upgrade your electronics toolkit and your diagnostics streamline. Hit that "Like" button, subscribe for more fantastic DIY projects, and let's get started on this informative journey!

Hi, i wanted to have a continuity tester (my multimeter doesn't have a buzzer) so i don´t have to look away from the circuit I am testing to see the multimeters display. Although i wanted a buzzer i also added a LED and an on/off switch for late night tinkering "stealth mode"

I don´t have any engineering or electronics background (actually i am a surgeon), but i love to make stuff and i am self teaching electronics with the help from Google and instructables.com. This is my first instructable and English isn´t my native tongue, so bear with me please...

DISCLAIMER: If following this guide anything/anyone/yourself damages i shall not be held responsible.Do it at your own risk. Take all the safety measures (goggles, gloves, etc)

-Highlighter (worn out)

-Pen

-Blue LED

-switch

-555 IC

-0.01uF ceramic capacitors= 2

-1uF electrolitic capacitor = 1

-180 k resistor = 1

-56k resistor= 1 (i did it on the weekend with no stores opened, so i used 47k + 10k series resistors)

-Piezo buzzer= 1 (i used a Hycom HY-07 that i took from an old modem)

-Button cell batteries= 3

-Battery holder (from a cheap pen/flashlight I had)

-Wires

-Soldering Iron

-hot glue gun

-xacto knife

First of all, I took apart the highlighter, threw away the tip and the ink cartridge by cutting the back end with an xacto knife. And I did the same to the flashlight/pen in order to take the battery holder away.

I found a buzzer circuit ( http://electronic-circuits-diagrams.com/alarmsimages/alarmsckt5.shtml ) the easiest and simple circuit I could find and tried it on the breadboard. It worked out fine, except I changed the 10k resistor (pins 7 and 8 of the 555 IC) for a 180k resistor because I liked the tone better.

i soldered all together over the 555 directly trying to make it as compact as possible (although i had plenty of room inside the highlighter, i did that way just in case i want to house it in a smaller pen someday)

-I stuffed some solder with the wires into a BIC pen tip (it´s a little messy because of the ink) and heated them with the soldering iron. -Then wired the tip to the (-) leg of the led and the pin 1 of the 555 IC.

-The (+) leg of the LED and the pin 4 of the 555 (through the on/off switch) to the positive pole of the battery pack.

-The secondary probe (another used pen) with a wire wrapped around the tip to the negative pole of the battery pack

When the two probe tips touch each other (or through a conductive material such as a wire or a circuit track) the circuit closes and the LED lights up and the buzzer vibrates with a nice tone.

The buzzer can be turned off with the switch, while the LED still lights up with continuity.

-I made a hole on one side of the highlighter so I could install the small switch I had

The buzzer and the battery holder are housed in the cap that clips on the end (that was reattached with a hole so wires can pass through and hot-glued). This allows me to change the batteries when they die.