Einstein
Temporal Engineer
- Messages
- 5,399
I've been attempting to get a Tesla coil to turn on and off with the use of electrical signals. Been trying to do this now for several months. I'm working with a free running feedback controlled oscillator using feedback from the secondary coil to drive the primary coil. So far apparent success has only been on a breadboard circuit. When I transfer the circuit over to a more permanent printed circuit board construction, the coil will not start up. There appear to be some unknown variables at work that I am trying to ascertain.
I have a homemade electrical field sensor that I accidentally discovered how to make. I thought I had hooked up my scope test leads to an old coil I had laying around so I could monitor the electrical field on my oscilloscope. But I later found out the coil was actually a bifilar coil. So my test leads were actually hooked up to a pair of coils that wound up being an open circuit. But I was getting an AC waveform in the 220KHz range. When hooked up this way, no magnetic field is picked up, just voltage. The sensor kind of works like a capacitor. Except the voltage comes out of space instead of one of the coils. Anyway instead of using the cob sensor I was using, I decided to make a dedicated sensor into a more durable format. So I wound 10 bifilar turns of magnet wire onto a 3" coil form and permanently attached a BNC cable to one end of the coil. Mounted this assembly onto an adjustable stand. This electrical field sensor has been immensely helpful in observing the behavior of the electrical field produced by a Tesla coil. I did gain some knowledge about the coil with this sensor that is not out there in the Tesla coil community. I always thought that a Tesla coil runs at its own fixed resonant frequency. But it turns out that any object within the radius of the Tesla coil field can affect the resonant frequency. The biggest change is observed when I walk toward the coil. The resonant frequency rapidly drops. I know adding an object with surface area to the output of the Tesla coil adds to the capacitance of the coil causing a drop in frequency also. But since I'm actually not connected to the coil, I suspect my body behaves like additional capacitance to the coil. I guess I could call it applied field capacitance.
I did experience some very odd behavior when troubleshooting my latest circuit board construction. One time when connecting the power wire, the Tesla coil fired up, but immediately turned off again when I pulled my hand away from the power wire. As I moved my hand back to disconnect the power wire, the Tesla coil started back up. How odd I thought. Same thing happened again as I pulled my hand away. Moved my hand close again and it started back up. So I slowly moved my hand away. That worked. But this is like playing cat and mouse. But it is a clue. Right now I'm attempting to find something that can act as a substitute for my hand. I do know that my presence in the voltage field will act like a capacitor. So finding a substitute method seems like my present course of action.
Then there was a very odd electrical discharge which I decided to record and have it here for you to see. When holding a metal rod close to the Tesla coil output. Both the coil and the metal rod discharge an arc toward a point in space. Making a distinct angle in the process.
After that I had my variable signal input set to 5 Hz and my field sensor started to oscillate back and forth. Seems to be a resonant frequency at work causing the apparent motion. But that would mean the coil is wirelessly attracting an object. Similar in some respects to gravity.
I have a homemade electrical field sensor that I accidentally discovered how to make. I thought I had hooked up my scope test leads to an old coil I had laying around so I could monitor the electrical field on my oscilloscope. But I later found out the coil was actually a bifilar coil. So my test leads were actually hooked up to a pair of coils that wound up being an open circuit. But I was getting an AC waveform in the 220KHz range. When hooked up this way, no magnetic field is picked up, just voltage. The sensor kind of works like a capacitor. Except the voltage comes out of space instead of one of the coils. Anyway instead of using the cob sensor I was using, I decided to make a dedicated sensor into a more durable format. So I wound 10 bifilar turns of magnet wire onto a 3" coil form and permanently attached a BNC cable to one end of the coil. Mounted this assembly onto an adjustable stand. This electrical field sensor has been immensely helpful in observing the behavior of the electrical field produced by a Tesla coil. I did gain some knowledge about the coil with this sensor that is not out there in the Tesla coil community. I always thought that a Tesla coil runs at its own fixed resonant frequency. But it turns out that any object within the radius of the Tesla coil field can affect the resonant frequency. The biggest change is observed when I walk toward the coil. The resonant frequency rapidly drops. I know adding an object with surface area to the output of the Tesla coil adds to the capacitance of the coil causing a drop in frequency also. But since I'm actually not connected to the coil, I suspect my body behaves like additional capacitance to the coil. I guess I could call it applied field capacitance.
I did experience some very odd behavior when troubleshooting my latest circuit board construction. One time when connecting the power wire, the Tesla coil fired up, but immediately turned off again when I pulled my hand away from the power wire. As I moved my hand back to disconnect the power wire, the Tesla coil started back up. How odd I thought. Same thing happened again as I pulled my hand away. Moved my hand close again and it started back up. So I slowly moved my hand away. That worked. But this is like playing cat and mouse. But it is a clue. Right now I'm attempting to find something that can act as a substitute for my hand. I do know that my presence in the voltage field will act like a capacitor. So finding a substitute method seems like my present course of action.
Then there was a very odd electrical discharge which I decided to record and have it here for you to see. When holding a metal rod close to the Tesla coil output. Both the coil and the metal rod discharge an arc toward a point in space. Making a distinct angle in the process.
After that I had my variable signal input set to 5 Hz and my field sensor started to oscillate back and forth. Seems to be a resonant frequency at work causing the apparent motion. But that would mean the coil is wirelessly attracting an object. Similar in some respects to gravity.
If I had to guess about the decay rate, I'd say the resistance probably changed when you took it off the breadboard. Decay rates are determined by capacitance, inductance, and resistance, and it seems unlikely that the first two of those changed unless you used different components.
