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creating my own driver, sch attached

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MrMatt

Fri Oct 28 2011, 12:43AM

Registered Member #4156 Joined: Fri Oct 21 2011, 05:19PM
Location:
Posts: 15

Ok I am modifying my driver circuit for my SSTC / DRSSTC. I am using a lab DC supply of 2.8kw at 62 volts. Therefore i am going to use a FET based driver. I have the provisional circuit attached, i still need to add some bypass caps and a few other bits.

I looked over Steve Ward's driver circuit and hope mine will function in a similar way. My circuit has on board oscillator (555 plus FF), DRSSTC and external clock options. Interrupter and over current are also implemented. I will be putting fiber receivers for the interrupter and external clock options.

Have a look and any advice is appreciated.

thanks
Matt
]tesladriver.zip[/file]

LuceÅ¡

Fri Oct 28 2011, 12:11PM

Registered Member #4108 Joined: Sun Sept 25 2011, 11:43PM
Location:
Posts: 149

just letting you know, with 62 volts its not going to want to draw very much current, Most people put voltage doublers to get upwards of 200volts.

MrMatt

Fri Oct 28 2011, 06:04PM

Registered Member #4156 Joined: Fri Oct 21 2011, 05:19PM
Location:
Posts: 15

in preliminary tests i was pulling almost 40 amps rms in CW with 60 volts on the bridge and a somewhat de-tuned primary circuit (about 1.6 ohms, inductive). I know i wont be pulling huge amps at this voltage, but i dont see why i cant get a couple hundred if i tune me LC primary to near zero ohms when running with an interrupter

MrMatt

Fri Oct 28 2011, 06:06PM

Registered Member #4156 Joined: Fri Oct 21 2011, 05:19PM
Location:
Posts: 15

these are my coil parameters
J A V A T C version 12.5 - CONSOLIDATED OUTPUT
October-28-11 11:05:58 AM

Units = Inches
Ambient Temp = 68Â°F

------------------------------------------- ---------
Surrounding Inputs:
------------------------------------------ ----------
48 = Ground Plane Radius
60 = Wall Radius
80 = Ceiling Height

------------------------------------------ ----------
Secondary Coil Inputs:
------------------------------------------ ----------
Current Profile = G.PROFILE_LOADED
3 = Radius 1
3 = Radius 2
12 = Height 1
37.5 = Height 2
1020 = Turns
23 = Wire Awg

--------------------------------------------- -------
Primary Coil Inputs:
------------------------------------------ ----------
Round Primary Conductor
5 = Radius 1
8 = Radius 2
12 = Height 1
17 = Height 2
6 = Turns
0.25 = Wire Diameter
0 = Ribbon Width
0 = Ribbon Thickness
0.15 = Primary Cap (uF)
0 = Total Lead Length
0 = Lead Diameter

---------------------------------------- ------------
Top Load Inputs:
------------------------------------------ ----------
Toroid #1: minor=6, major=25, height=38, topload

----------------------------------------- -----------
Secondary Outputs:
----------------------------------------- -----------
148.33 kHz = Secondary Resonant Frequency
90 degÂ° = Angle of Secondary
25.5 inch = Length of Winding
40 inch = Turns Per Unit
0.00243 inch = Space Between Turns (edge to edge)
1602.2 ft = Length of Wire
4.25:1 = H/D Aspect Ratio
32.3486 Ohms = DC Resistance
30383 Ohms = Reactance at Resonance
2.47 lbs = Weight of Wire
32.6 mH = Les-Effective Series Inductance
34.352 mH = Lee-Equivalent Energy Inductance
33.535 mH = Ldc-Low Frequency Inductance
35.315 pF = Ces-Effective Shunt Capacitance
33.514 pF = Cee-Equivalent Energy Capacitance
52.966 pF = Cdc-Low Frequency Capacitance
7.55 mils = Skin Depth
29.52 pF = Topload Effective Capacitance
103.5821 Ohms = Effective AC Resistance
293 = Q

----------------------------------------------- -----
Primary Outputs:
----------------------------------------- -----------
114.2 kHz = Primary Resonant Frequency
23.01 % high = Percent Detuned
59 degÂ° = Angle of Primary
20.42 ft = Length of Wire
3.39 mOhms = DC Resistance
0.722 inch = Average spacing between turns (edge to edge)
1.864 inch = Proximity between coils
0 inch = Recommended minimum proximity between coils
12.948 ÂµH = Ldc-Low Frequency Inductance
0.08892 ÂµF = Cap size needed with Primary L (reference)
0 ÂµH = Lead Length Inductance
141.678 ÂµH = Lm-Mutual Inductance
0.215 k = Coupling Coefficient
0.135 k = Recommended Coupling Coefficient
4.65 = Number of half cycles for energy transfer at K
19.77 Âµs = Time for total energy transfer (ideal quench time)

Dr. ISOTOP

Fri Oct 28 2011, 09:06PM

Registered Member #2919 Joined: Fri Jun 11 2010, 06:30PM
Location: Cambridge, MA
Posts: 652

MrMatt wrote ...

in preliminary tests i was pulling almost 40 amps rms in CW with 60 volts on the bridge and a somewhat de-tuned primary circuit (about 1.6 ohms, inductive). I know i wont be pulling huge amps at this voltage, but i dont see why i cant get a couple hundred if i tune me LC primary to near zero ohms when running with an interrupter

Even if it pulls thousands of watts, it'll still have derpy sparks; SSTCs want voltage, not raw power.

MrMatt

Fri Oct 28 2011, 09:48PM

Registered Member #4156 Joined: Fri Oct 21 2011, 05:19PM
Location:
Posts: 15

How much of a restriction does low drive put on arc length?. When running CW right now i am getting about a 14" arc. I would imagine if I ran an interrupter at 10% or so and jacked up the current the arcs would lengthen quite a bit. Never the less this circuit could be used to drive GDT just as easy as the primary in the future. Another idea that pops into my head is a transformer, but that may be a headache to build one that would not survive such high peak powers

LuceÅ¡

Fri Oct 28 2011, 10:27PM

Registered Member #4108 Joined: Sun Sept 25 2011, 11:43PM
Location:
Posts: 149

why don't you post some pics and schematics

MrMatt

Fri Oct 28 2011, 10:46PM

Registered Member #4156 Joined: Fri Oct 21 2011, 05:19PM
Location:
Posts: 15

schematic preliminary is in first post, very similar to what i am using right now/ was using I did something dumb and blew the driver chip. i was just adding interrupter, better on board clock source, and drsstc options as well as over current protection.

would to nice to know if i am on the right track with self resonant driver in my circuit as attached above

pic attached of coil, and yes i did fry those alligator leads, was doing some low power tuning and forgot to take them off. oops

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