This circuit is an Electrostatic Polarity Detector, it is able to detects electrostatic charges and indicates their polarity with two LEDs (Red LED = Positive charge, BLUE LED = Negative charge). The core of this circuit is a CD4011, a Gate NAND IC.
For this project I decided to make the circuit on a prototyping board, and as box I used a glass jar, which gives it a particular look with a vintage tone given by the amber LED that constantly lights up the base.
Operation controls on the cap of the glass jar:
- ON/OFF/ON Switch - Turns the device on and off in normal or low power mode, the low energy consumption mode is possible thanks to a 180-ohm 1/2-watt resistor placed on the power line.
- ON/ON Switch - used for select internal or external antennas.
- ON/OFF Big Red Button - Used to select one of the two resistances placed in series with the antennas, you can choose between 3M ohm and 1K ohm.
- RCA Female connector - Used to connect a custom-made external antenna.
Operation of the LED display:
🔴Red = Positive charge
🔵Blue = Negative charge
🔴RED + 🔵BLUE at the same time = AC Voltage⚡️
Components:
1x Small Antenna DIY (made with metal wire)
1x Big Antenna DIY (made with metal wire and male RCA)
1x 4011 IC
2x 68pF Ceramic Capacitors
2x 330 Ω Resistors 1/4 Watt
1x 180 Ω Resistor 1/2 Watt
1x 3 MΩ Resistor 1/4 Watt
2x 1 KΩ Resistor 1/4 Watt
1x Red LED (for Positive Charge)
1x Blue LED (for Negative Charge)
1x LED as power LED (any color)
2x 1N4148 Diodes
1x 1N4007 Diode
1x Stripboard
1x ON/ON Switch (for select antennas)
1x ON/OFF/ON Switch (for power on)
1x ON/OFF Button
1x RCA Female connector
1x RCA Male connector
1x Glass jar
Other material needed:
- Hot glue
- Soldering tin
- Spacers for electronics
- Screws for spacers
- Heat shrink tubing
- Wire foe electronics
- Metal wire
- 9 Volt Battery
Extra material i used (NOT NECESSARY):
- I added a second 9 Volt battery connector directly on the board
- I added a second ON/OFF switch on the board
A bit of theory📚 (from www.wikipedia.org )
Electrostatics is a branch of physics that studies electric charges at rest.
Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber was thus the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law.
There are many examples of electrostatic phenomena, from those as simple as the attraction of plastic wrap to one's hand after it is removed from a package, to the apparently spontaneous explosion of grain silos, the damage of electronic components during manufacturing, and photocopier & laser printer operation. Electrostatics involves the buildup of charge on the surface of objects due to contact with other surfaces. Although charge exchange happens whenever any two surfaces contact and separate, the effects of charge exchange are usually noticed only when at least one of the surfaces has a high resistance to electrical flow, because the charges that transfer are trapped there for a long enough time for their effects to be observed. These charges then remain on the object until they either bleed off to ground, or are quickly neutralized by a discharge. The familiar phenomenon of a static "shock" is caused by the neutralization of charge built up in the body from contact with insulated surfaces.
- Electric field:
The electric field, in units of newtons per coulomb or volts per meter, is a vector field that can be defined everywhere, except at the location of point charges (where it diverges to infinity). It is defined as the electrostatic force in newtons on a hypothetical small test charge at the point due to Coulomb's Law, divided by the magnitude of the charge in coulombs.
Electric field lines are useful for visualizing the electric field. Field lines begin on positive charge and terminate on negative charge. They are parallel to the direction of the electric field at each point, and the density of these field lines is a measure of the magnitude of the electric field at any given point.
Consider a collection of particles of charge, located at points (called source points), the electric field at (called the field point).
- Friction Electrification:
Is a method of electrification which consists in the transfer of electric charge (electrons) from one body to another.
The body that gives up electrons becomes positively charged while the one that receives them becomes negatively charged.
The electrification by friction is obtained substantially by rubbing the two bodies together and the passage of the electrons present on the surface derives from the friction that the rubbing produces.
Chapters:
00:00 - Intro
01:00 - Explanation
02:45 - Test
03:40 - AC & HV
03:48 - Extra
03:56 - Circuit
04:04 - END
⚠️WARNING: This video is only for demonstration. I don't take any responsibility.
#Detector #Electronic #EMF
8 июл 2024
