Tesla coils are also called Tesla coils, because this is a direct transliteration of the English name “Tesla”. This is a distributed parameter high frequency series resonant transformer that can obtain high frequency voltages of millions of volts. The principle of the traditional Tesla coil is to use a transformer to boost the ordinary voltage, and then charge the resonant capacitor of the primary LC circuit. When the resonant capacitor is charged to the discharge threshold, the spark gap discharge is turned on, and the primary LC circuit undergoes series resonance, providing sufficient supply to the secondary coil. The high excitation power, followed by the frequency equal to the secondary LC loop, makes the inductance of the secondary coil and the distributed capacitance resonate in series. At this time, the discharge terminal voltage is the highest, so lightning can be seen. In layman’s terms, it is an artificial lightning generator. There are enthusiasts of Tesla coils all over the world, and they have made all kinds of devices to create blinding artificial lightning, which is very beautiful.
How Tesla Coils Work
The principle of the Tesla coil is to use a transformer to boost the ordinary voltage, and then discharge the device from the discharge terminal through the two-pole coil. The Tesla coil is coupled by two loops through the coil. First, the power supply charges the capacitor C1, when the voltage of the capacitor is high When the threshold value of the spark gap is exceeded to a certain extent, the spark gap breaks down the air spark, the path of the primary coil of the transformer is formed, the energy oscillates between the capacitor C1 and the primary coil L1, and is transferred to the secondary coil by coupling. Secondary The coil is also an inductance, and the connection between the top cover C2 and the ground can be equivalent to a capacitor, so LC oscillation will also occur. When the two-stage oscillation frequency resonates at the same frequency, the energy of the primary loop will surge to the secondary, and the discharge end will The voltage peak will continue to increase until discharge.
Tesla Coil Making
The first is the required materials.
[Enameled wire]The diameter of 0.2-0.3 can be used, about half a catty, depending on the size of the secondary coil, the price of 20-30 yuan can be purchased in the Electronic market;
[PVC pipe]A 50-75mm, length 30-50cm, a diameter of 100mm, a length of 10-20cm, a total price of 10 yuan aluminum exhaust pipe, as the top of the discharge, one meter in length, about 80mm in diameter, the price is 15 yuan The above two materials can be bought in hardware stores or building materials market
[Induction cooker capacitor]1200V 0.3UF, need 10-30 pieces, about 1.5 yuan a piece
【High-voltage power supply】You can use NE555, TL494 and other chips to drive the high-voltage package of the TV, and generate a high voltage of more than 20000V, but a better way is to use a ZVS driver, which has high power, less heat, and stable and reliable work.
Then there is the production process.
1. Wind the secondary coil, and use the enameled wire to wind 1000-1500 circles on the PVC pipe with a diameter of 50-75mm;
2. Make the top of the discharge, as shown in the figure below, use an aluminum exhaust pipe. For the convenience of fixing, you can clamp the aluminum pipe with two stainless steel bowls up and down, and drill holes in the middle to fix it with screws. Aluminum basins, stainless steel hollow balls, stainless steel bowls, plates, cans and other metal objects with large surface area can also be used as the discharge tip. It should be noted that the discharge tip should be connected with the enameled wire on the upper end of the secondary coil;
3. Connect the top of the discharge and the enameled wire on the secondary coil with a wire;
4. Make the primary coil, and wrap the thick wire around a 10cm diameter pvc pipe. In order to facilitate debugging, you can also peel the single-core copper wire and fix it on the pipe as shown in the figure below. Note that each turn must be left for quality inspection. There are gaps
5. Make a primary capacitor array. Every 10 capacitors are connected in series as a group, and multiple groups are connected in parallel as needed. For safety, each capacitor must be connected in parallel with a 1m resistor;
6. To make a lighter, fix two metal objects on the insulator with a distance of 3-5mm. In order to dissipate heat, several groups can be connected in series.
The key to making a Tesla coil is to resonate, that is, the primary LC frequency should be equal to the secondary LC frequency. After calculation, you will find that L1C1≠L2C2, you need to adjust the number of turns of the primary coil to get the required inductance value. The number of turns of the primary coil should not be too small. When the adjustment of the number of turns cannot meet the resonance condition, you can adjust the primary coil by increasing or decreasing the capacitor group, and then adjust the primary coil. After determining the approximate number of turns, connect the circuit well and power on to observe the discharge effect. , then power off, fine-tune the primary turns (eg 5.7, 8.2 turns) until the arc is the longest.
Tesla coils are high-voltage devices, and it is strictly forbidden to touch any part of the circuit when it is powered on!
After these steps, a simple Tesla coil is completed. Turn on the power, and the lightning made by yourself appears in front of you.