Credit Card Sized Contactless Voltage Detector (555)

The idea came looking at other Instructable:

https://www.instructables.com/id/Contactless-Volta...

I have chose the design with the 555 because I had several 555 around and I like build small projects, like this other credit card sized project.

https://www.instructables.com/id/Credit-Card-Sized...

This is a screenshot from the project of :

https://www.instructables.com/member/Tarantula3/

The Component are:

• 555 Timer
• Credit card
• battery holders (recycled)
• 2032 coin batteries
• 10 kΩ resistor
• 220 Ω resistor
• 4,7 μF electrolytic capacitor
• buzzer
• led
• switch
• copper tape (antenna)
• epoxidic glue (few drops)

Tools:

• solder
• cutter

As you can see in the photo, pretty ugly.

But it was working, so I started to work to the final version.

As you can see in the video it is working and with good sensitivity, actually I had to keep the antenna very short due to the high sensitivity.

I used a 1kΩ resistor instead of 220Ωto reduce the sound of the buzzer .