Plasma Speaker Audio Modulated Solid State Tesla Coil

 

ABSTRACT:

This paper explicates the simple design of the Plasma Speaker: Audio Modulated Solid State Tesla coil that have advantages compared to the typical Tesla Coil. The proposed design has a similar functionality with the typical Tesla coil where it is able to produce high voltage with high frequency current at the secondary circuit side. The significant part of the proposed design is that it works on direct current voltage as the input voltage unlike typical Tesla Coil. The design only needs a low direct current voltage as an input for the primary circuit. According to the LT Spice simulation, it proved that the schematic design has the capability to step up the energy and voltage at the secondary winding at least 100-150 times greater compared to the input voltage. The input to the primary circuit of Tesla Coil is an audio signal which acts as a source of low direct current voltage, at the output i.e. at the secondary coil an amplified audio signal is generated. Eventually, at the output side the charge accumulated gets so high that it breaks free in a spectacular burst of electric current in the form of audio signal.

 

 

 

I. INTRODUCTION:

In 1981, Nicola Tesla designed a system consisting of two coupled resonant circuits-primary circuit and secondary circuit. The primary circuit can be charged to a desired voltage level or high voltage level. When the capacitor gets fully charged and the spark gap is completed the primary circuit has current flowing through it. By the faradays electromagnetic induction law a secondary voltage is induced in the secondary circuit. Thus energy is transferred to the secondary circuit. When the energy transfer is complete the spark gap is turned off and the complete cycle repeats again. In this way the resonance is achieved.

 

This arrangement was earlier used to generate high secondary voltage in the form of corona discharge or sparks. Also this was conceived as a wireless transmission circuit to transfer the power wirelessly. On the secondary end of the arrangement a load is connected to complete the RLC circuit.

 

Although this type of tesla coil has got limited applications, the modern solid state tesla coil has more applications and efficient output.

 

Fig 1. Spark Gap Tesla Coil

 

II. SOLID STATE TESLA COIL (SSTC):

These uses power semiconductor devices usually transistors such as MOSFETs or IGBTs to switch pulses of current from a DC power supply through the primary winding. They provide pulsed (disruptive) excitation without the disadvantages of a spark gap: the loud noise and high temperatures. They allow fine control of the voltage, pulse rate and exciting waveform. This type is used in most commercial, industrial, and research applications as well as higher quality entertainment coils.

 

If a solid state inverter is used to feed energy into the sys   -tem, the primary coil no longer needs to be driven by a resonant circuit. In fact, it can even be eliminated entirely this is known as the base feed drive method. It has some major shortcomings, but   provides a starting point foranalyzing the behavior of the more practical two-coil SSTC.

 

The base-fed   SSTC is nothing more than an air-core

Inductor connected to a signal generator that is set to the

coil’s resonant frequency. A simple low power experiment can demonstrate the behavior of such a system. In the following circuit, a 1V RMS, 637 kHz sine wave is used to power a 100W Bulb. The resonator coil is wound with a single layer of 32 SWG copper magnet wire on a PVC pipe.

 

Fig 2. SSTC Driver

 

III. CIRCUIT DIAGRAM:

 

Fig 3. Slayer Exciter Circuit

 

Turning the circuit on, R drives the base of the transistor Q

Q turns on and drives current into the primary of the transformer. The current is limited by the limited available base current.

 

The created magnetic field drives the secondary of the transformer.

 

The secondary voltage wants to grow large. But the tiny stray capacitance on the output resists the change, although very small, against the rise of the output end and so in return the voltage on the other end of the transformer goes down, pulling the base of the transistor low.

 

Diode D prevents the base voltage to fall more than 0.7V below ground, which in return pushes the output end of the secondary high.

 

The transistor turns off and so the magnetic field starts to reduce.

The base voltage rises again and Q turns on and the cycle repeats.

 

IV. SIMULATION:

 

Fig 4. Voltage at the input side

 

Fig 5. Voltage at the output side

 

The simulation of our project was done on lt spice software. The circuit using solid state tesla coil was considered (as shown in figure) .the input voltage was an audio signal with 9v direct current voltage. The output obtained was 5.6kv dc voltage. This concludes the required very high level output voltage as compared to conventional tesla coil with spark gaps that produces 2KV output voltage.

 

V. PLASMA SPEAKERS:

The plasma speakers are a form of loudspeaker which varies air pressure via a high energy electrical plasma instead of a solid diaphragm. The audio input given to the plasma speaker circuit is amplified at the output and produced in the form of electric arc or glow discharge. The produced effect is based on two principles.

Firstly, ionization of gases causes their electrical resonance to drop significantly, making them extremely efficientconductors, which allows them to vibrate sympathetically with magnetic fields.

Secondly the involved plasma, itself a field of ions, has a relatively negligible mass. Thus as current frequency varies, more resistant air remains mechanically coupled with and is driven by vibration of more conductive and essentially massless plasma,radiating a potentially ideal reproduction of the sound source.

Conventional loudspeaker uses transducer electrical frequencies to vibrate a substantial mass. This plasma speakers are more appealing and more efficient than the conventional loudspeakers. Also it has exceptional transient response over conventional loudspeaker.

 

VI. CONCLUSION:

Although the solid state tesla coil has independently got its own wide application by using it in plasma speaker’s circuit will give more significant and effective results. The output voltage is 2 times more than using a basic tesla coil circuit that uses old spark gap concept. Moreover the disadvantages of spark gap are removed by using solid state tesla coil. It can produce more audio voltage output with quality sound.

 

VII. References:

1.        James Corum and James Daum,"Tesla Coil Research" ,1992

2.        George F. Haller,"The Tesla High Frequency Coil",1910

3.        R. C. Weast, CRC Handbook of Chemistry and Physics, 62nd ed., CRC Press, Inc., 1981.

4.        Sean Soleyman, “Solid State Tesla Coils and Their Uses”,http://www.eecs.berkeley.edu/Pubs/TechRpts/2012/EECS-2012-265.html, December 14, 2012.

5.        Nikola Tesla, “Tesla Coil”, US Patent 512340 A, 1894.

 

Received on 14.12.2015            Accepted on 04.08.2018      ©A&V Publications all right reserved Research J. Engineering and Tech. 2018;9(4): 293-296. DOI: 10.5958/2321-581X.2018.00039.9