Welcome all concerned to the high-voltage discharge!
As you know, electronic lamp appeared in the first half of last century and long before the advent of semiconductor devices used to create different devices. Lamp, in contrast to the usual transistors and circuits have a fairly large size (especially the high powered bulbs, they can be truly gigantic), fragile glass casing are extremely hot and in the process, and require high supply voltages, along with power-hungry filament. If you combine all these factors, it becomes clear pretty quickly why the lamp went out of use. However, their relevance today still remains – enthusiasts around the world create designs collected exclusively on the lamps. This approach does not carry any benefit in terms of a saving, or space saving in the housing, on the contrary, tube road design to manufacture and bulky. But they have one important advantage – unmatchable authenticity and vintage appearance, which can not boast of modern semiconductor devices. In addition, when assembling the lamp design there is a touch of something special, elitist, and perhaps not quite deservedly forgotten. The lamps quite often collect a Tesla coil – after the first coil was collected on the lamps in those days, when semiconductor elements simply did not exist. Vacuum tube Tesla coil is quite simple in the repetition scheme, it is presented below.
As you can see in the right part of the diagram shows directly the coil itself – its secondary and primary winding, and the winding connections necessary for proper operation of the circuit. The secondary coil – a particularly important element of the scheme, it largely will depend on whether the start of the scheme, and the size of a corona discharge. The maximum that can be achieved with this scheme is 5-7 cm, which is quite good considering the simplicity of the scheme. The secondary winding should contain 600-1500 turns of thin copper enameled copper wire, wound turn to turn. It seems that to produce such a coil is a long and time-consuming activity, but actually, the coil is wound in just one evening, if you collect pre-small winding machine. Just need to ensure free rotation of the secondary frame below, rotating it quickly to wind the wire which will come from the roll. Wound coil can be coated transparent dielectric varnish, if the coil is wound smoothly, turn to turn, and without bias, only one form of this reel is already impressive. As the primary in the diagram you can see two windings, the upper contains 20-30 turns, and the bottom, respectively, 15-25, it is possible to use copper enameled wire with a diameter of about 1 mm. They need to be wound only in one direction.
In the diagram you can also see the lamp itself – as it is possible to use a 6P45S, or GU-50. The first lamp used in tube TVs, in horizontal scan, and therefore it is possible to look for together with old TVs. Or you can buy in specialized stores lamps but unfortunately, the prices these lamps are not cheap. Note that the intensity of the 6P45S is powered by a voltage of 6.3 V, the current consumption is about 3A, and the intensity of GU-50 should be powered from 12.6 V, it will consume a current of approximately 0.7 A. filament need to consider when choosing a power source for the circuit. At the same time to supply voltage to the intensity of the above provisions is not necessary – the filament inside the lamp might just burn out, and if the voltage is less than nominal, the circuit will not start.
In the left part of the diagram shows the input voltage, it can be 200-250V. It is not recommended to connect the circuit directly in the socket – in this case, the current will not be nothing limited, in the case of incorrect Assembly schemes are possible unwanted pyrotechnics 🙂
Also in this case will be no galvanic isolation from the mains, and therefore is very easy to get an electric shock from this design. The ideal option is to use a decoupling transformer, the output of which is the same 220V, with a power of 100-200W. Or you can obtain the necessary voltage by connecting the secondary windings of multiple transformers in series. The circuit can operate in two modes – directly from the power source, or with the multiplier and a circuit breaker which is shown at the bottom of the diagram. In the first case the breaker is not used, and the voltage is fed directly to the input of the schematic of the Tesla coil. Switching between modes is accomplished by the simultaneous switching of all the keys in the diagram. The capacitor C1 on the circuit – trimming, is used to configure a resonance scheme, i.e. to achieve the most powerful level. Here you need to use a capacitor with an air dielectric, designed for high voltage – to find a capacitor at any tube radio and record. The diodes in the rectifiers need to use a voltage at least 1500 V, current 1A.
The picture above shows the circuit breaker, it is based on the NE555 chip. It is powered with DC voltage 6-12V, and the output provides a continuous sequence of rectangular pulses. Pulse frequency of the output signal is regulated by a trimming resistor PR1. Also on the diagram you can see four jumpers, each of which corresponds to the capacitor – this part of the circuit provides a discrete switch between different frequencies of operation of the breaker. If desired, it can not be used, leaving only one capacitor with a capacitance of 1-10 pF.
Vacuum tube Tesla coil generates and radiates strong electromagnetic fields, crosstalk, and therefore in the diet will not prevent high-frequency filter diagram is shown below. Its use is not required, but if the coil is not working properly, it is necessary to put.
Also, this design can be improved by replacing a simple circuit breaker on ionion – in this case, the Tesla coil will be singing, that is able to play sounds. Diagram of the console of ionophone shown below, connects it instead of the breaker. This circuit is powered from 12-15V and generates rectangular pulses at the output, but does so to the beat of the music. Input for audio on the diagram shown under the designation “Audio jack”. Here you can submit an audio signal, for example, player or phone.
The whole construction of a Tesla coil going in the enclosure from the computer power supply. The metal housing ensures good strength and coil will certainly current fight, if not to the beginning of the secondary winding earthed.
In the upper part of the body is drilled a large hole for installing the panels under the lamp. The anode of the lamp 6P45S – at the top of the container, connect to it, you can just twist the wires, or clip-crocodile. Also on the diagram you can see the transistor, through which the circuit breaker “connects” with the schema of the coil as it is possible to use any sufficiently powerful NPN transistor. You need to place it on the radiator, if the casing is metal, the radiator may be even the body wall. Control knob frequency interrupter and an air condenser in the circuit of the coil are brought out of the housing.
The design of the lamp coil is rather capricious, and therefore can not start the first time. In this case, do not worry, you need to try to change the relative position of the primary coils, their distance from the secondary. To validate the installation, and when you have painstaking the scheme is definitely working, if everything is assembled correctly.
One of the interesting experiments with the Tesla coil ion motor. Made of thin iron or copper wire is manufactured rotor with two ends of the taper, looking in different directions. This rotor fits over the top of the secondary winding so that its free unwinding. When you turn the coil corona will be formed on the tapering of the rotor, thereby spinning it. This phenomenon, when a corona discharge pushes the rotor, called the ion winds, in the dark looks awesome, this can be seen by watching the photo below. A good build!
Welcome all concerned to the high-voltage discharge!