microBrute DRSSTC Tesla Coil Kit
November 2019, Rev 5
− 10 −
Copyright © 2011, Eastern Voltage Research, LLC
microBrute DRSSTC Instruction Manual
Introduction to the microBrute DRSSTC Tesla Coil Kit
Thank you for purchasing the microBrute DRSSTC Kit. The microBrute DRSSTC is a
smaller version of our miniBrute DRSSTC system, and is our entry level DRSSTC Tesla
Coil kit. It’s a popular choice for individuals building their first disruptive based solid
state Tesla coil. The small coil produces output arcs, similar to that of a disruptive spark
gap coil, in excess of 15" and with proper tuning can achieve arc lengths approaching
20”. It also features both a self-resonant feedback circuit which tunes the coil
automatically and an active current limiting circuit which protects the solid state
switching devices from being driven with too much current. The microBrute DRSSTC is
controlled through the use of the microBrute handheld controller.
Notice to Beginners: If you are first time kit builder, you may find this instruction
manual easier to understand than expected. Each component in this kit has an individual
check box, while a detailed description of each component is provided as well. If you
follow each step in the instruction manual in order, and practice good soldering and kit
building skills, the kit is next to fail-safe.
Please read this manual in its entirety before building, testing, or operating your kit!
Circuit Description
The microBrute DRSSTC is a relatively simple second generation DRSSTC system
comprised of only a few major subcircuits. The low voltage 18VAC transformer, T2,
along with bridge rectifier, BR1, and filter capacitor, C12, provide the DC voltage
required for the Tesla coil’s control circuitry. The 7815 linear regulator, U6, provides
+15VDC which is used to provide power to the gate driver circuits, while the 7805 linear
regulator, U7, provides the +5VDC to power the control logic devices. Rectifiers, CR43
and CR44, along with capacitors, C42 and C43, provide a voltage doubling network
which convert the input 115VAC to approximately 340VDC. This 340VDC is the bus
voltage of the half-bridge switching circuit. The self-resonating drive network is
comprised of current transformer, T1, and control logic devices, U1, U2, and U3. T1
samples the primary current of the DRSSTC, and converts this current to a voltage square
wave through the clamping network consisting of CR1, VR1, CR2, and VR2. This
dev5V square wave, which is at the resonant frequency of the Tesla Coil, is used
to drive the Tesla Coil into oscillation. The 9A gate driver ICs, U4, and U5, are driven
by this signal, and provide the +15V/-15V gate drive necessary to switch the half-bridge
switching circuit ON and OFF. Gate transformer, T41, simply provides voltage isolation
between the control circuitry and the half-bridge as the half-bridge is bouncing up and
