A Single PCB Full-Bridge
Solid State Tesla Coil
Solid State Tesla Coil 4 Platform
My SSTC 3 project turned out to
be a good experience in developing my first single-PCB tesla coil. It went pretty
well, but I wanted a little bit more power and had several ideas I
wanted to improve upon for the design. As a result, I decided to modify the SSTC 3 to utilize SMD components,
and added another half
bridge to form a full-bridge for the main inverter. The result is SSTC 4 - a single PCB,
General Purpose Solid-State Tesla Coil Platform capable of
swappable interrupters like a graphics card on a computer, and
configurable for us as a DRSSTC with the addition of a tank cap.
- Note: this page is still under construction!
More to come soon.-
SSTC 4 Project Status: Tested at 120VAC and 240VAC! (Oct 2015)
*Boards for Sale*: I had a bunch of leftover boards
left from the development of this project. Please see my
sales page for more information.
SSTC 4 Specifications (July 2015):
- Compact footprint and mounting holes to fit and mount
exactly in almost all ATX power supply cases (only because they do make
for a cute box!)
- Laminated Full-Bridge topology with low bus
inductance, accepting 4 of your favourite TO-247 IGBTs or MOSFETs
- Robust discrete push-pull MOSFET driver
- Commercial drop-in GDTs for easy assembly, and great performance
- Generous heat-sinking for the full bridge
- General purpose feedback allowing Antenna, Primary Current, Secondary
Current or direct Secondary feedback
- On-PCB logic transformer with switch for easy dual voltage (120 or
240VAC input) operation!
- Swappable interrupters / controllers like GPUs on a motherboard -
compatible with SSTC 3
- Safety protection, bleeder resistors, Under Voltage Lockout, Fuse (5 x
- Add one resonant capacitor and an external bus cap to convert this
into a DRSSTC (has flip-flop for zero current turn-off!)
- Added spade-connectors for easy external connections
22 Sept 2015
The SSTC 4 single-PCB Tesla Coil was developed as a
full-featured all-purpose Solid State Tesla Coil platform for building a
compact yet powerful full-bridge coil, all on a single PCB. This
revision was developed as an improvement over my reliable and proven
SSTC 3 half-bridge platform, and builds upon it with many improvements.
Full-bridge operation allows significantly more power output compared to
Like the SSTC 3, the SSTC 4 platform was designed
primarily to be run from the sine-wave ramp from the mains ('ramped
mode'), but can be easily converted to regular SSTC operation with the
addition of a bus cap, and also into a DRSSTC with the addition of a
tank capacitor. The board was designed to be easy to hand-solder despite
using some SMD components.
Full schematics for SSTC 4 are available here. Hopefully this will be
useful to those looking to develop their own designs.
I also developed a very simple test interrupter to go along with SSTC 4.
SSTC 4 was designed primarily to be run in ramped-mode like SSTC 3. This
simple interrupter offers a dual functionality of a mains zero-crossing
detector (via the 12V transformer) and also allows of optical input from
an external controller. In order to reduce parts count, the analog
staccato interrupter used in SSTC 3 has been updated to use only an
optocoupler + a small Atmel microcontroller (ATtiny45/85). SSTC 4's
interrupter input has the same pin-out as SSTC 3 for compatibility.
The source code for the controller can be downloaded here (source
Swapping the DIP packages for SMD saved me a bit of
space on the PCB for the large heatsink and additional two IGBTs.
Some features include a laminated bus, multiple
footprints for input/output connections, and laminated gate drive lines.
Improvements from SSTC 3 include a more robust
discrete MOSFET push-pull drive for the GDTs, off-the-shelf GDTs for solder-and-play
operation (no more worrying if you got the phase right!), as well as an
integrated switch for both 120VAC and 240VAC universal operation.
Populating the boards
Finally I got the PCBs fabricated and I'm glad to say that it turned out
very nicely, and fits almost all ATX power supply boxes perfectly :-).
Admittedly, a steel ATX box is hardly the best enclosure for a SSTC
operating at a few hundred kHz, but nevertheless it makes for a cute
Building a Coil
One of the first few coils I built using the SSTC 4 platform was a very
simple and small SSTC running in 'ramped-mode' off the mains sine-wave
ramp, for my friend Philip. This coil runs on 120VAC and was designed to
be a simple, plug-and-play coil which could run reliably and fairly
quietly as a very simple demo unit with zero set up time. As a result,
the coil was not strictly optimized for performance, but nonetheless
produces decent, small sword sparks and effectively serves its purpose
as a good demonstration unit!
Phil helped to take the photo above of the coil in action!
More to come soon, do check back often for updates!
Back to main page
(c) Gao Guangyan 2020
Contact: loneoceans [at] gmail [dot] com