Electronics mini projects 2012

1. Telephone Operated Machine 
2. Locker Security Monitor 
3. DTMF BASED ROBOTIC CONTROL 
4. GPS Based train or bus or Aircraft Collision Avoidance 
5. ETHERNET BASED INDUSTRIAL MONITORING AND CONTROL SYSTEM 
6. WIRELESS SECURITY SYSTEM FOR APARTMENTS 
7. Accident identification with auto dialer 
8. Power Monitoring System for Motors 
9. Data Logger With Graphics Display 
10. Remote Mouse Controlled Automation 
11. Oscilloscope using Graphics LCD 
12. CDMA Based Mobile Communication 
13. Car security system 
14. Implementation of CAN communication between 8051 microcontrollers 
15. HOME AUTOMATION USING CAN 
16. INTELLECTUAL SPEED CONTROL USING PROXIMITY SYSTEM & RF 
17. TRACKING AND BREAKING SYSTEM FOR VEHICLES 
18. Intelligent Traffic Light Switching for Emergency 
19. Industrial monitor. 
20. RF Card Based Security Accessing. 
21. Scrolling message Display 
22. Home Automation System 
23. Centralized wireless monitoring in textile industries 
24. Glass Breakage Detector 
25. PC- printer communication through power line 
26. Motor Speed control using IR Sensor 
27. Quality Control System 
28. Tension control system 
29. Control Design for Vehicle Speed With Multilevel Using Wireless Communication 
Technology 
30. Portable Recording System for Monitoring Vehicle Speeds 
31. ETHERNET BASED PATIENT MONITORING SYSTEM 
32. DC Motor Speed controlled using Remote 
33. PC interfaced Data Acquisitions System 
34. Prepaid Card for Call Taxi 
35. Cryptography using Microcontroller 
36. Temperature Monitoring using Thremistor 
37. TOUCH SCREEN CONTROLLER BASED DRIVING SYSTEM 
38. Stepper Motor controlled By Remote Control 
39. Personal Safety And Tracking Through GPS 
40. TRANSFORMER MONITORING 
41. Digital IC Tester 
42. Embedded lift controller 
43. Machine control & fault recognition through telephone 
44. CAN BASED DEVICE CONTROL USING GSM 
45. Congestion Control In ATM Networks Using ASIC in VLSI 
46. Design of USB host 
47. Monitoring System for UPS. 
48. ZIGBEE BASED HEART RATE MONITORING 
49. INTELLIGENT LIBRARY MANAGEMENT SYSTEM 
50. Remote Dish Positioning System 
51. Telephone Switching 
52. Capacitance Meter 
53. OUTDOOR LOCATION TRACKING USING GPS AND RFID 
54. Programmable Serial Hub 
55. Attendance recorder 
56. Code Modulation Based Encryption and Decryption Technique for Secure 
Communication in Wireless 
57. SURVEILLANCE SYSTEM FOR RAILWAYS 
58. On-load Tap-change for power transformer 
59. Phone Book Dialer 
60. Air Leakage Detection Based on Pressure Sensor 
61. VOICE BASED GUIDANCE SYSTEM FOR VISUALLY IMPAIRED USING GPS 
62. Power factor monitor & control 
63. PROCURE SYSTEM FOR VEHICLE USING CAN PROTOCOL 
64. TCP/IP BASED STUDENT ATTENDANCE LOGGING SYSTEM 
65. SECURE SYSTEM FOR DOMESTIC PURPOSE 
66. CARGO MANAGEMENT SYSTEM 
67. Temperature Data Logger 
68. SMS Enabled Industrial Networking 
69. Digital Anemometer 
70. Mobile car Security System 
71. ETHERNET BASED PATIENT MONITORING SYSTEM 
72. Electricity theft Identification using RF Modems 
73. Security Integrated System Based On WAP For Remote Monitoring and Control of 
Industrial Process 
74. Railway Gate Management using GPS and GSM 
75. Priority for Emergency Vehicles in Traffic Signals 
76. WIRELESS SENSORY BASED ENERGY CONSERVATION SYSTEM 
77. Programmable Hopper Controller 
78. TCP/IP BASED ENERGY MONITORING SYSTEM FOR ELECTRICITY BOARD 
79. Wireless Temperature Monitoring and Controlling Using Embedded System 
80. GPS GSM based patient monitoring 
81. Security System for Remote Access using Telephone Line 
82. I2C EPROM Programmers 
83. Multi-channel Temperature Monitor & controller 
84. RF Based Embedded Virtual Highway Patrol 
85. Mail Transfer System 
86. Lift control System 
87. Tyre pressure monitoring system 
88. WIRELESS SECURE POLLING SYSTEM USING GPRS 
89. Accident identification system 
90. Pc to Microcontroller communication Through USART. 
91. Wireless Water Level Controller 
92. Traffic Priority for Ambulance 
93. Telephone interface security system 
94. VOICE BASED AUTO RECEPTIONIST FOR EDUCATIONAL INSTITUTION USING DTMF 
95. Inbuilt protector for motors 
96. Device Switching through Card System. 
97. Irrigation control system 
98. Motion Recorder & Play Back 
99. Time Annunciation 
100. Data feeding system through card

IEEE SEMINAR TOPICS 2012

1.    Design of integrated meter reading system based on power-line communication 

2.    Non intrusive Load Monitoring and Diagnostics in Power Systems 

3.     A survey of communication network paradigms for substation automation 

4.     Automatic repeat protocol for distribution automation system through power line communication 

5.     Street lighting control based on Lon Works power line communication 

6.     Design of integrated meter reading system based on power-line communication 

7.     An Integrated Architecture for Demand response Communications & Control 

8.     Automatic Power Meter Reading System using GSM Network 

9.     Software Agents Based Home Automation An Intelligent Electrical Billing & Maintenance 

10.   Get on Digital Bus to Substation Automation

11.   Unified Architecture for Large Scale Attested Metering 

12.   GSM mobile system to monitor brain function using a near-infrared light sensor 

13.   A gain scheduling strategy for the control and estimation of a remote robot via Internet 

14.   Smart companion [contextual communication services] 

15.   Open architecture for contactless smartcard-based portable electronic payment systems 

16.   Optimized Autonomous Space In-situ Sensor-Web for Volcano Monitoring 

17.   A mobile web grid based physiological signal monitoring system 

18.   Bluetooth/GMRS Car Security System with a Randomly Located Movement Detect Device 

19.   Bluetooth Based Wireless Remote Device Controlling and Data Acquisition 

20.   Bluetooth Remote Control 

21.   Application of Bluetooth technology in ambulatory wireless medical monitoring 

22.   A Remotely Controlled Bluetooth Enabled Environment 

23.   Coupling between Bluetooth modules inside a passenger car 

24.   Remote-controlled home automation system via Bluetooth home network 

25.   Home appliance control system over Bluetooth with a cellular phone 

26.   Usage of Bluetooth TM in wireless sensors for tele-healthcare 

27.   Remote system for patient monitoring using Bluetooth 

28.   Using Bluetooth transceivers in mobile robot

Reference: http://seminarprojects.com/Thread-ieee-electrical-projects#ixzz1tA8uILR0

INFRARED ELECTRONIC SHOOTING GAME

TK. Hareendran

just trigger an infrared electronic gun and there goes one invisible bullet hitting the bull’s eye, if timed properly. The circuit is very simple, inexpensive and easy to construct. The game offers hours of fun and excitement. The target screen consists of a number of LEDs moving rapidly in a circular fashion. All the LEDs are red except one—the real target located in centre of the screen which is green. When a shot is fired by triggering the gun, all LEDs go off except one. If it happens to be the target (green LED) then you have made a hit which is indicated by lighting up of another green LED accompanied by a pleasing musicaltone. After a short delay the game restarts automatically. Infrared gun (transmitter) for this electronic game is built around IC1 timer (NE555) wired as an astable multivibra tor with a centre frequency of about 35 kHz. The frequency is determined by the timing components comprising resistors R1 and R2 and capacitor C2. When push-to-on trigger switch S1 is pressed, the astable multivibrator starts modulating the infrared beam with short pulses (See output waveform).

 The whole circuit can be enclosed in a toy gun for giving it a professional look as illustrated in the figure. The infrared LED has to be fitted with a suitable reflector to ensure good sensitivity. When power switch S2 in the receiver is turned on, astable multivibra-tor wired around IC3 (NE555) generates clock pulses which are fed to clock input (pin 14) of decade counter IC4 (CD4017B). This IC has ten outputs, and each one goes high sequentially on the rising edge of successive clock pulse. As a result,  LEDs connected to the output appear to move from one to the other rapidly. You would notice that only nine outputs are used for driving LEDs. The tenth output (Q9) at pin 11 is connected to reset pin 15. When gun is fired, infrared bursts are received by the integrated infrared module and its output at pin 2 goes low. The resulting falling edge triggers monostable  IC2 and its output (pin 3) goes high. This makes clock enable (CE) pin 13 of IC4 to go high (normally held at a low potential via resistor R8) and it starts counting. When mono pulse ends, and if the last lit LED happens to be the target LED then both inputs of NAND gate N1 become high. As a result, the output of gate N2 also goes high. This in turn switches on transistor T2; thereby the ‘HIT’ LED lights up and the buzzer also sounds. At the end of the mono pulse period (about 5 sees), decided by resistor R5 and capacitor C5, the mono IC2 is again ready to receive another trigger pulse. Assembly and component layout is not very critical. 

The circuit may be assembled on a veroboard using IC sockets. A well regulated power supply is required for powering the unit. In place of the IR transmitter it is also possible to make use of the remote control used for TVS or VCPs/VCRs.

BUILD A BATTERY POWERED TESLA COIL

This is intended to be a how-to guide for a newbie to high voltage (like myself) looking for a quick, cheap, and relatively safe project. Although this is not a true tesla coil, as it does not utilize a resonant air-core transformer or operate at high frequencies, in effect it is similar. It still throws out plasma discharges from the top load and about 3.5 centimeter arcs to ground. Estimated output is about 100kv.

You need the following

Fig. 1

There aren't many parts to this build, and most can easily by scrounged from old TVs and other electronics or be bought for cheap. The following is needed:

Bug zapper racquet: This can be purchased from Ocean State Job Lot for about 5 bucks, and is nifty for fending of mosquitos or high voltage experiments. There are probably other types of devices very similar, but I would recommend finding the racquet pictured to insure the internal circuitry is the same.

Flyback transformer: Any flyback transformer will do, though the bigger the better. Don't kill yourself looking for an old non-rectified design, since there are no benefits of it for this circuit.

Random assorted hardware: This circuit requires a spark gap to be constructed. The design of the spark gap can vary, as long as the two ends where the arc jumps is rounded, and the gap adjustable. For mine, two Erector set brackets were used. One had a ball bearing soldered to it, the other a nut over top the hole, so a bolt with an acorn nut on the end can be threaded through. See the attached picture for the details. 

2xAA battery holder: Can be purchased from Radioshack or the bug zapper handle can be used to hold the batteries.

Optional: 

Additional Capacitors: Should be rated for at least 1.6 KV. The Bug zapper already contains one, but for bigger sparks more can be used.

Toggle Switch: The switch on the board of the bug zapper can be difficult to use, and because of the design of the bug zapper circuit, floats at high voltage, leading to a shock hazard when it is exposed. Because of this, a new switch is recommended.

Pen body or other plastic tube: To elevate the top load

Top load: I used a ball bearing, but anything smooth and without sharp edges or points can be substituted. 

Of course, solder and a soldering iron as well as other general tools are needed, and wire for connecting everything together

Dismantle the Zapper

The bug zapper is easy enough to open. First, pry off the battery cover, and then remove the screws. There are two up near the head of the racquet, two near the bottom of the battery compartment, and another at the top of the battery compartment. Once removed, the back half of the handle can be lifted off, exposing the back of the circuit board. Remove the screw in the middle of the circuit board, and snip the wires running to the head of the racquet as close to the head of the racquet as possible, and snip the wires where they attach to the battery contacts. Now that the board is removed, the rest of the racquet is not needed.

Prepare the Zapper Circuit

Now that the circuit is removed, it has to be slightly modified for our needs. First, remove the original momentary push switch, and in its place solder a jumper. Next, remove the negative battery wire from the board, and solder in its place the lead from the AA battery holder. Solder the positive battery wire on the board to the normally open lead on the toggle switch, and the positive lead from the battery holder to the common lead on the toggle switch. If you have extra capacitors, these can be used to make a capacitor bank. if you go this route, desolder the capacitor from the board, and set aside with the other capacitors. If you choose to not do this, leave the capacitor in its place. One of the black wires from the board's output can also be removed, since it is not needed. If you choose to make a capacitor bank, see below. Otherwise, the board is all set. The final product with capacitor bank is showed below, mounted on a piece of painted mdf.

Capacitor Bank:
This is relatively simple to make. Find as many high voltage capacitors as you want to use and wire them in parallel. In my case, I chose to use six, for no apparent reason. They can be mounted on a perf board as shown for a neater appearance. 

Spark Gap

One of the wires from the zapper capcitor/capacitor bank feeds directly to the flyback transformer, which will be addressed in the next step, the other through the spark gap. The spark gap works to allow the capacitors to charge to the point when the electricity jumps the gap, and continues into the flyback. This creates short, powerful pulses to feed the flyback. The design of the spark gap can vary, but there are some general requirements:
It has to be adjustable for the width of the gap.
The ends of each electrode should be rounded.
The rounded shape is to prevent corona leakage between the electrodes. For my spark gap, one electrode is a ball bearing, the other a bolt with an acorn nut on the end. The electrodes are then mounted on Erector set pieces, and each nailed to the mdf that my whole setup is mounted on. the bolt can be screwed in or out to adjust the width of the gap. The wider the gap, the slower but more powerful the pulses, the narrower the gap, the faster but weaker the pulses. The gap then feeds into the flyback transformer. 

Flyback Transformer

This is easily the most time consuming and tedious part of the build. While many other people might rewind their own primary coils on the flyback, I prefer to use the ones already available, since they are already nicely potted in the flyback. Unlike most flyback driver circuits, which use a primary and feedback coil, this just uses one primary coil. To find the primary coil, its down to trial and error. Using a multimeter, measure the resistance across each pair of pins. I find that in a majority of flybacks, the primary coils (as there are usually more than one) are situated so that their inputs are next to each other. That being said, this is not always the case. As you measure across each set of pins, take note of their resistances, as the one with the lowest resistance has the fewer number of coils. This is the one we are after. However, make sure that this is an independent coil, and that there isn't a third pin connected to it. Once this coil is located, the secondary coil needs to be located. Part of this is already done, since one "pin" is the fat (usually red) wire that comes out of the top of the transformer and has a suction cup on the end. The method for locating the second pin is relatively crude. Connect a 9 volt battery to one of the primary coil pins with an alligator clip, and to the other primary coil pin, connect an alligator clip. Don't connect this alligator clip to the battery yet. Take fat the red wire, and with the suction cup removed and the end stripped, place it close to one of the unused pins. Tap the disconnected terminal of the battery with the loose alligator clip, and look for a spark between the wire and pin. If there is none, move it closer and try again. If there is still no spark, move onto the next pin. If the wire doesn't spark to any of the pins, reverse the polarity of the battery and try the whole process again. Eventually, you will come across the pin you are looking for. Before disconnecting the battery from the flyback, take note of the polarity of the primary coil pins. If you are using one of the new flybacks, the polarity is important, since they contain a rectifier and voltage multiplier circuit. Once the primary coil is located, solder two long wires to it, and to the pin that the fat red wire sparks to, solder another wire. Then, just to be safe, pot the pins in hot glue. Make sure to use plenty of glue, and fill all gaps and spaces. This prevents unwanted arcing. Once this is done, the coil is all set. 

Putting it All Together

The flyback is now ready to be wired into the rest of the circuit that we prepared. In my circuit, the positive output from the capacitor bank goes thought the spark gap, then to the flyback. The negative output from the capacitor bank goes directly to the flyback. In this way, the spark gap is wired in series with the flyback. Once this is all set, the circuit is ready to be tested. flip the circuit on, and the red LED that was already on the zapper board should light up. This means the circuit is running and the capacitors are being charged. If you don't get a spark across the spark gap, check the width of the gap. If the electrodes are touching, back the bolt out (or however your spark gap is set up) until a spark is achieved, or if they are too far apart, make the gap smaller. DON'T MAKE ADJUSTMENTS TO THE SPARK GAP WHILE THE CIRCUIT IS ON!!!!! If you do so, you will be shocked. Once you have a spark, put the fat red wire close to the wire soldered to the other pin of the secondary. You should have an arc jump the gap. If not move the wires closer. If you get an arc from the secondary coil of the flyback, give yourself a pat on the back, your circuit is done! if not, time for troubleshooting. Check all connections, make sure the capacitor bank is charging by using a high voltage multimeter to check the voltage across the capacitors, check the spark gap width, check the polarity of the primary coil connections to the flyback, and check to make sure you are using the proper pins. Once the circuit is working, it's time to package it all up. Below, the picture is after its been mounted to a piece of mdf and a top load added, which is addressed in the next step.

Top Load and Mounting the Circuit

To make the circuit function more like a classic Tesla Coil, one end of the secondary coil needs to be grounded. This is done by simply attaching it to a grounding post or cold water pipe. The pin of the secondary that should be grounded is the one on the bottom of the flyback. The fat red wire is connected to the top load. The top load is simply something metal and smooth, without any edges or points. A large ball bearing works well for this. I then glued the top load to a plastic pen body, with the wire running up the inside. to make the whole set up neater, it was mounted on painted mdf (medium density fiberboard). The wire running to the top load enter the side of the board, then takes a right turn up inside the pen body. The other wire from the secondary coil enters the board from the side, but then connects to a binding post, so that a grounded wire can be attached to it. You can choose to do it as I have done, or mounted everything in a box, or however. 

Using the "Tesla Coil": Turn the switch on, and with a grounded wire attached, plasma discharges will leave the top load. Because the discharges are low amperage, they are difficult to see in the light. In a dark room, once your eyes adjust, they are visible as white, mini lightning bolts. A wire can be attached to the grounding post, and placed near the top load, so it arcs to it. The longest arc I have recorded was about 3.6 cm long. The spark gap can be adjusted to achieve different results as well. Making the gap bigger leads to fewer pulses, as low as 1 a second, but leads to the most powerful discharges out of the top load. This is best when trying to achieve the largest arc to ground. Making the gap smaller leads to faster, but less powerful pulses. This is best for making plasma discharges into the air. Making the gap too small, however, will severely weaken the discharges. Finally, don't run the circuit for too long, no more than about 30 to 35 seconds at a time, as this can lead to the zapper circuit overheating and failing. 


Congratulations on your new AA battery powered "Tesla Coil"!. Have fun with it, show it off to family members and friends, and experiment with high voltage! Remember, just remember to use common sense and be safe.

For more details click on this link:

http://www.instructables.com/id/AA-Battery-Powered-Tesla-Coil

Plasma globe

Plasma globes, or plasma lamps (also called plasma balls, domes, spheres, tubes or orbs, depending on shape), are novelty items that were most popular in the 1980s.^[1] The plasma lamp was invented by Nikola Tesla^[2] after his experimentation with high-frequency currents in an evacuated glass tube for the purpose of studying high voltage phenomena, but the modern versions were first designed by Bill Parker.^[1] Tesla called this invention an inert gas discharge tube.^[3] 

Working principle

Most commonly, plasma globes are available in spheres or cylinders. Although many variations exist, a plasma lamp is usually a clear glass orb filled with a mixture of various gases (most commonly neon, sometimes with other noble gases such as argon, xenon and krypton) at nearly atmospheric pressure. They are driven by high-frequency alternating current at approximately 35 kHz, 2–5 kV, generated by a high-voltage transformer. A much smaller orb in its center serves as an electrode. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light (see corona discharge and electric glow discharge).

Placing a hand near the glass offers an attractive place for the energy to flow. The capacity of the body to accept radio-frequency energy is greater than that of the surrounding air. The energy available to the filaments of plasma within the globe will preferentially flow toward the better acceptor. The energy is flowing through the filaments, so the filaments move too. This flow also causes a single filament, from the inner ball to the point of contact, to become brighter and thinner.^[1] The filament is brighter because there is more current flowing through it and into the 150 pF capacity, or capacitance, presented by an object the size of a human. The filament is thinner because the magnetic fields around it, augmented by the now-higher current flowing through it, causes a magnetohydrodynamic effect called self-focusing: the plasma channel's own magnetic fields create a force acting to compress the size of the plasma channel itself.

An electric current is produced within any conductive object near the orb. The glass acts as a dielectric in a capacitor formed between the ionized gas and the hand.

The globe is prepared by pumping out as much air as is practical. The globe is then back-filled with neon to a pressure similar to one atmosphere. If the radio-frequency power is turned on, if the globe is "struck" or "lit", now, the whole globe will glow a diffuse red. If a little argon is added, the filaments will form. If a very little xenon is added, the "flowers" will bloom at the ends of the filaments.

The neon available for purchase for a neon-sign shop often comes in glass flasks at the pressure of a partial vacuum. These can not be used to fill a globe. Tanks of gas, each with its specific, proper, pressure regulator and fitting, are required: one for each of the gasses involved.

Of the noble gasses, radon is radioactive, helium escapes through the glass too quickly, and krypton is quite expensive. Other gasses can be used. The plasma will take apart any molecular gas.

Caution

Caution should be taken when placing electronic devices near or upon the plasma lamp: not only may the glass become hot, but the high voltage may place a substantial static charge on the device, even through a protective plastic casing. The radio frequency field produced by plasma lamps can interfere with the operation of touchpads used on laptop computers, digital audio players, cell phones, and other similar devices.^[1] Some types can radiate sufficient RFI to interfere with cordless telephones and Wi-Fi devices several feet away. If a medium-sized lamp is wrapped in grounded metal foil, capacitive coupling can transfer tens of milliamperes to ground through the foil, enough to light a small lamp or give a small arc burn. This is possible because the glass acts as a capacitor dielectric: the inside of the lamp acts as one plate, and any conductive object on the outside acts as the other capacitor plate.^[3] Ozone, which is harmful to humans, may also accumulate outside of the surface of the glass orb after a few minutes of constant operation.^[1]

Plasma globe

Plasma globes, or plasma lamps (also called plasma balls, domes, spheres, tubes or orbs, depending on shape), are novelty items that were most popular in the 1980s.^[1] The plasma lamp was invented by Nikola Tesla^[2] after his experimentation with high-frequency currents in an evacuated glass tube for the purpose of studying high voltage phenomena, but the modern versions were first designed by Bill Parker.^[1] Tesla called this invention an inert gas discharge tube.^[3] 

Working principle

Most commonly, plasma globes are available in spheres or cylinders. Although many variations exist, a plasma lamp is usually a clear glass orb filled with a mixture of various gases (most commonly neon, sometimes with other noble gases such as argon, xenon and krypton) at nearly atmospheric pressure. They are driven by high-frequency alternating current at approximately 35 kHz, 2–5 kV, generated by a high-voltage transformer. A much smaller orb in its center serves as an electrode. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light (see corona discharge and electric glow discharge).

Placing a hand near the glass offers an attractive place for the energy to flow. The capacity of the body to accept radio-frequency energy is greater than that of the surrounding air. The energy available to the filaments of plasma within the globe will preferentially flow toward the better acceptor. The energy is flowing through the filaments, so the filaments move too. This flow also causes a single filament, from the inner ball to the point of contact, to become brighter and thinner.^[1] The filament is brighter because there is more current flowing through it and into the 150 pF capacity, or capacitance, presented by an object the size of a human. The filament is thinner because the magnetic fields around it, augmented by the now-higher current flowing through it, causes a magnetohydrodynamic effect called self-focusing: the plasma channel's own magnetic fields create a force acting to compress the size of the plasma channel itself.

An electric current is produced within any conductive object near the orb. The glass acts as a dielectric in a capacitor formed between the ionized gas and the hand.

The globe is prepared by pumping out as much air as is practical. The globe is then back-filled with neon to a pressure similar to one atmosphere. If the radio-frequency power is turned on, if the globe is "struck" or "lit", now, the whole globe will glow a diffuse red. If a little argon is added, the filaments will form. If a very little xenon is added, the "flowers" will bloom at the ends of the filaments.

The neon available for purchase for a neon-sign shop often comes in glass flasks at the pressure of a partial vacuum. These can not be used to fill a globe. Tanks of gas, each with its specific, proper, pressure regulator and fitting, are required: one for each of the gasses involved.

Of the noble gasses, radon is radioactive, helium escapes through the glass too quickly, and krypton is quite expensive. Other gasses can be used. The plasma will take apart any molecular gas.

Caution

Caution should be taken when placing electronic devices near or upon the plasma lamp: not only may the glass become hot, but the high voltage may place a substantial static charge on the device, even through a protective plastic casing. The radio frequency field produced by plasma lamps can interfere with the operation of touchpads used on laptop computers, digital audio players, cell phones, and other similar devices.^[1] Some types can radiate sufficient RFI to interfere with cordless telephones and Wi-Fi devices several feet away. If a medium-sized lamp is wrapped in grounded metal foil, capacitive coupling can transfer tens of milliamperes to ground through the foil, enough to light a small lamp or give a small arc burn. This is possible because the glass acts as a capacitor dielectric: the inside of the lamp acts as one plate, and any conductive object on the outside acts as the other capacitor plate.^[3] Ozone, which is harmful to humans, may also accumulate outside of the surface of the glass orb after a few minutes of constant operation.^[1]