Monday, 8 August 2011

Tesla coil; first attempt.

Tesla coil is a type of resonant transformer, where the voltage output from the secondary turn is not dependent on the turns ratio between primary and secondary turns, but dependent on the square root of the ratio between primary inductance and secondary inductance.

Here is my first attempt on building a mini Tesla coil. The secondary coil (where the sparks will be observed) is a 500-turn winding, wound around a kitchen naptkin's cardboard roll of 5cm outer diameter and of 20cm length. The primary coil is 8-turn winding, wound around a big glue tape roller of about 9cm outer diameter. I drive this coil using ZVS power oscillator (see schematic here) but using different type of capacitor (1uF, non polar). Like no other configuration of the ZVS, this new configuration of ZVS i ve been using rendered the MOSFETs very hot after 1 minute running time, forcing me to put heatsinks on each MOSFET.

Running on 12V, 3.16A power supply fed into the ZVS circuit. I am still researching on how to enlarge the spark and make them blue since the purple spark is not a spark, its a corona due to presence of water vapor around the carrying conductor.

I dont know why the camera suddenly perceived the spark as blue although it was purple.

In the dark.

I m using spark gap, so this tesla coil can be regarded as SGTC (spark gap tesla coil).

The capacitor i ve been using is a single homemade leyden jar, made from 275ml juice bottle, with brine in it and aluminium on the outer part as plates.

Here is the schematic of the tesla coil from the high voltage output. The diode is already in the flyback transformer that receives oscilated current from the ZVS circuit.

I m still improving the design to get larger spark and less hot transistors. See ya later.

No comments:

Post a Comment