Builds a simple non-contact voltage detector

[Dino] is back with another installment of his Hack a Week series, and in this episode he is taking on what he promises will be the last transistor-based project ???at least for a little while.
In the video embedded below, he shows off a homemade voltage detector circuit that he constructed using a trio of BC547 NPN transistors. The circuit is pretty simple though very useful all the same. At one end, the device has a small copper strip, which is connected to the base of the first transistor. The emitter of that transistor is daisy chained to the base of the second transistor and so on, until reaching the indicator LED.
As noted by one of [Dino’s] viewers, the circuit functions as follows:
“The front end copper strip forms one side of a capacitor, and then when you bring it near a voltage potential a super tiny current flows between air dielectric of the “cap??? This is mega amplified with the high gain BC547′s and viola, the LED lights up.???
Since the small bit of current is amplified many times over, the LED lights up even when very small voltages are present. While we might not necessarily trust our lives to [Dino’s] voltage detector, we’re sure it would come in handy now and again.

Share this post
About the Author

Admin
How to Send Micro:bit Data to ThingSpeak IoT Platform
January 11, 2018
VC0706 Camera Module DIY Guide
December 18, 2014
nRF24L01 Module Demo for Arduino
May 6, 2011
Topics
- Curriculum
- Course
- Micro bit supplier
- Wholesale Suppliers
- Micro bit tutorial
- Micro bit classroom pack
- Mcorbit Environment Monitoring
- Temperature-controlled
- Motor
- Fan
- TPBot car
- TPBot
- Micro:bit car
- AI Lens
- Micor:bit AI Lens
- Micro:bit LEDs
- BBC micro:bit
- Micro:bit Manipulator
- Wukong board
- Cutebot
- Micro:bit Motorcycle
- Nezha breakout
- Micro:bit DIY
- 360° servos
- AI Lens
- Retro Arcade
- Ecode
- PlanetX
- Microbit programming
- Your:bit
- Do your:bit
- IoT:bit
- Octopus
- Rainbow LED Ring
- Joystick:bit
- Wonder Building Kit
- Sensor:bit
- Downie
- Wenjie
- Laser Engraver Tutorial
Tags
Micro:bit
DIY
micro bit course
micro bit curriculum
micro bit supplier
micro:bit supplier
micro bit classroom pack
micro:bit classroom pack
micro bit tutorial
micro:bit tutorial
TPBot
micro:bit car
AI Lens
micro:bit AI Lens
microbit gyroscope
Micro:bit LEDs
BBC micro:bit
Micro:bit Manipulator
Wukong board
Cutebot
micro:bit Motorcycle
nezha breakout
micro:bit music
360° servos
AI Lens
Retro Arcade
ecode
PlanetX
sonar:bit
Microbit programming
your:bit
do your:bit
IoT:bit
Octopus
Rainbow LED Ring
Joystick:bit
Wonder Building Kit
Laser Engraver
Laser Engraving Machine
Wish List
Comments