eastern microBrute User manual

microBrute Modulator
May 2010, Rev 1 − 1 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
m
mi ic cr ro oB Br ru ut te e M Mo od du ul la at to or r
I
In ns st tr ru uc ct ti io on n M Ma an nu ua al l
E
Ea as st te er rn n V Vo ol lt ta ag ge e R Re es se ea ar rc ch h, , L LL LC C

microBrute Modulator
May 2010, Rev 1 − 2 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Introduction to the microBrute Modulator
Thank you for purchasing the microBrute Modulator / Interrupter Kit. The microBrute
Modulator is a handheld controller (interrupter) that was specifically designed for use
with the microBrute DRSSTC system. It features two potentiometers which the user can
adjust in real time to control both the pulsewidth as well as the pulse repetition frequency
(PRF) of the modulation (pulsing).
The microBrute Modulator can also be modified by the user to utilize different ranges of
pulsewidths and PRFs to suit most any SSTC or DRSSTC system.
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 Modulator utilize two 555 Timer ICs to perform the pulse timing logic.
555 Timer, U1, runs in astable (continuous) mode, providing the PRF, of the modulation,
while 555 Timer, U2, is configured as a monostable (single pulse) one-shot. U1 produces
a continuous series of pulses, whose frequency is determined by the RC network
comprised of C2, R2, and R3, and is adjustable by the user by varying potentiometer R3.
The frequency of these pulses equate to the pulse repetition frequency (PRF) of the
interrupter. Each of these pulses then triggers U2 to produce a one-shot pulse of some
varying pulsewidth, which is determined by the RC network comprised of C7, R6, and
R5. The pulsewidth of this one-shot can be varied by the user by adjusting
potentiometer, R5. The figure on the next page shows the output timing of the
modulator.
When operating the microBrute DRSSTC, power output is controlled by varying the
pulsewidth, or R5. When pulsewidth is equal to “0”, the DRSSTC is in an OFF state.
When pulsewidth is increased, the DRSSTC output power is gradually increased.

microBrute Modulator
May 2010, Rev 1 − 3 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Kit Building Tips
A good soldering technique is key! Let your soldering iron tip gently heat both the wires
and pads simultaneously. Apply solder to the wire and the pad when the pad is hot
enough to melt the solder. The finished joint should appear like a small shiny drop of
water on paper, somewhat soaked in. If the pads have not heated up sufficiently, melted
solder (heated only by the soldering iron itself) will form a cold solder joint and will not
conduct. These cold joints appear as dull beads of solder, and can be easily fixed by
applying additional heat to the pad and wire. All components, unless otherwise noted,
should be mounted on the top side of the board. This is the side with the silkscreen
printing.
When installing components, the component is placed flat to the board and the leads are
bent on the backside of the board to prevent the part from falling out before soldering.
The part is then soldered securely to the board, and the remaining lead length is clipped
off. It is also extremely important to place the components as close to the board as
possible. This is necessary for proper operation over the wide frequency range of the
various kits we provide. Also be sure that component lead lengths are always as short as
possible. This will avoid adding any stray capacitances or inductances that can be
detrimental to circuit operation.
An alternative approach (which is actually the one I use) is to install the component into
the board and then apply a piece of masking tape on the topside to the hold the
component in temporarily. The leads on the backside of the board are then trimmed
leaving about 0.10” lead protruding through the backside of the board, and then soldering
from the backside. You can then remove the masking tape, apply a small amount of
solder on the top to complete the joint.

microBrute Modulator
May 2010, Rev 1 − 4 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
microBrute Modulator Parts List
RESISTORS
1 1.5k Resistor (brown-green-red), R1
1 51k Resistor (green-brown-orange), R2
1 1k Resistor (brown-black-red), R4
1 100k Resistor (brown-black-yellow), R7
1 100k Panel Mount Potentiometer, R3
1 10k Panel Mount Potentiometer, R5
CAPACITORS
3 0.1uF Capacitor, C1,C2,C5
1 0.015uF Capacitor, C7
3 0.01uF Capacitor, C3,C4,C6
DIODES
1 Diode, 1N4002, CR1
1 LED (red or green), Panel Mount, D1
INTEGRATED CIRCUITS (ICs)
2 555 Timer, U1,U2
MISCELLANEOUS
1 Connector, RCA, Female, J1
1 Plastic Enclosure
1 9V Battery Connector, BAT1
1 Panel Switch, ON-OFF, SW1
2 Knob, 1/8” Shaft
1 Front Panel Plate
1 Misc. Hardware
1 Misc. Hook-up Wire
REQUIRED, NOT SUPPLIED
1 9V Battery

microBrute Modulator
May 2010, Rev 1 − 5 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
microBrute Modulator Component Layout Diagram

microBrute Modulator
May 2010, Rev 1 − 6 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
KIT Building Instructions
Now we will begin building the kit. There are just a few more important things to know
before we install the first components.
For each component, the word “install” always means the following:
1. Pick the correct value to start with.
2. Insert the component into the correct printed circuit board (PCB) location.
3. Orient the component correctly – especially when there is a right and a wrong
way to solder it in. (i.e. Electrolytic capacitors, diodes, ICs, transistors, etc…)
4. Solder all connections unless directed otherwise. Ensure enough heat is used to
allow solder to flow for clean, shiny, and completed connections.
Also, please be sure to take us seriously when we say that good soldering is the key to the
proper operation of your circuit!
•Use a 25W soldering pencil with a clean, sharp tip. DO NOT USE a high power
soldering gun such as those trigger activated units.
•Use only rosin core solder intended for electronics use
•Ensure your work area is clean, and has plenty of bright lighting
•Build your kit in stages, taking breaks to check your work. Be sure to clean the
board periodically with a brush or compressed air to remove any excess wire
cuttings, etc…
Okay, so lets begin!
1. Install R1, 1.5k resistor (brown-green-red)
2. Install R2, 51k resistor (green-brown-orange)
3. Install R4, 1k resistor (brown-black-red)
4. Install a jumper (short) in the R6 location. You can use the excess lead that
you cut off from another resistor to do this.
5. Install R7, 100k resistor (brown-black-yellow)
6. Install CR1, 1N4002 diode. The cathode band on the diode must match that
shown on the silkscreen.
7. Install C1, 0.1uF capacitor (marking BC104)

microBrute Modulator
May 2010, Rev 1 − 7 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
8. Install C2, 0.1uF capacitor (marking BC104)
9. Install C5, 0.1uF capacitor (marking BC104)
10. Install C3, 0.01uF capacitor (marking BC103)
11. Install C4, 0.01uF capacitor (marking BC103)
12. Install C6, 0.01uF capacitor (marking BC103)
13. Install C7, 0.015uF capacitor (marking BC153)
14. Add a jumper (short) from U3, Pin 1 to U3, Pin 4.
15. Install U1, 555 Timer. The 555 Timer IC may be soldered directly to the
PCB without worry, but you may use an 8-pin DIP socket (your own) if you
prefer. Use the same care in soldering such a socket and inserting the IC as you
would in direct soldering of the chip. Note that one end of the IC is marked by a
dot, notch, or band; this end MUST be oriented as shown on the PCB layout.
16. Install U2, 555 Timer. The 555 Timer IC may be soldered directly to the
PCB without worry, but you may use an 8-pin DIP socket (your own) if you
prefer. Use the same care in soldering such a socket and inserting the IC as you
would in direct soldering of the chip. Note that one end of the IC is marked by a
dot, notch, or band; this end MUST be oriented as shown on the PCB layout.
17. Solder approx. 3-4" of wire lead to each of the following locations on the
PCB board:
a. J1+
b. J1-
c. +9V
d. R3+
e. R3-
f. R5+
g. R5-
18. Using a utility knife or scroll saw, cut out a rectangular hole as shown in the
figure below. EXTREMELY IMPORTANT - First line up the both the top and
bottom piece of the enclosure and fit together. You want to ensure to cut the right
end of the top piece of the enclosure as there are two stand-offs which will
interfere with the battery compartment if you cut the wrong end of the top piece
of the enclosure.

microBrute Modulator
May 2010, Rev 1 − 8 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
19. Using a 1/4" Drillbit, drill a hole approximately 2/3rd across the top of the
end of the top piece of the enclosure, as shown in the figure below, for the RCA
connector, J1. Be sure not to drill in a location that will interfere with the internal
stand-off.
20. First, use rubbing alcohol to clean the top surface of the enclosure where the
control plate will be installed. Next, carefully peel away the adhesive backing on
the control plate, position it, and then press firmly to stick it in place. Apply lots
of pressure over all areas of the control plate to ensure good contact with the
enclosure surface.

microBrute Modulator
May 2010, Rev 1 − 9 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
21. First, using a multimeter, determine which switch position of the switch is the
ON position. This ON position will be the top of the switch. Press fit SW1, ON-
OFF rocker switch into the front control plate cut-out. The ON position will be
pointing up.
22. Press fit D1, panel mount LED into the front control panel hole. This hole is
directly to the right of the rocker switch. If the LED is loose, you may use epoxy
(not supplied) or a similar adhesive to secure it in place.
23. Install R3, 100k potentiometer, into the RIGHTMOST front control plate
potentiometer location. Secure in place using the included lock washer and nut.
Be sure not to overtighten the nut as you may damage the potentiometer.
24. Install R5, 10k potentiometer, into the LEFTMOST front control plate
potentiometer location. Secure in place using the included lock washer and nut.
Be sure not to overtighten the nut as you may damage the potentiometer.
25. Connect BAT1 and SW1 to the PC board as shown in the figure below. Be
sure to ensure proper polarity during connection, or you may damage the active
components such as U1 and U2.
26. Connect D1 to the PC board as shown in the figure below. The black lead of
the panel mount LED should be connected to the pad of D1 designated with a "K"
as this is the cathode.
27. Connect R3, 100k potentiometer, to the PC board as shown in the figure
below. Be sure to connect the wires to the potentiometer pins EXACTLY as
shown in the figure below to ensure that the PRF adjusts in the correct direction
when turning the potentiometer. This is VERY important.
28. Connect R5, 10k potentiometer, to the PC board as shown in the figure
below. Be sure to connect the wires to the potentiometer pins EXACTLY as
shown in the figure below to ensure that the PW adjusts in the correct direction
when turning the potentiometer. This is VERY important.
29. Connect J1 to the PC board as shown in the figure below. The center lead of
the connector should connect to the pad marked “+” on the PC board.

microBrute Modulator
May 2010, Rev 1 − 10 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual

microBrute Modulator
May 2010, Rev 1 − 11 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Congratulations! You have just completed your microBrute Modulator kit. Please take a
few moments to look over the board and ensure that all the components are installed
properly with the correct orientation. Since some of the parts may be unfamiliar to you,
you may want to be extra sure that they have been inserted correctly. After you are sure
that everything seems to be properly installed, move on to the set-up and testing section.
Set-up and Testing
Okay, so lets begin!
RECOMMENDED TEST EQUIPMENT, NOT SUPPLIED
1 Analog or Digital Multimeter
1 Oscilloscope (not required, but can be useful if you wish to verify timing)
1. Connect the 9V battery to the battery connector and turn the power switch ON.
Using a multimeter, verify the voltages below:
Check Component Measuring Point Voltage
U1 Pin 8 (Vcc) 9V ±0.5V
U1 Pin 4 (Reset) 9V ±0.5V
U2 Pin 8 (Vcc) 9V ±0.5V
Note: All voltages should be measured with respect to the GND screw terminal.
2. Verify that LED, D1, is illuminated. If it is not, and the voltages above are
correct, the LED may be installed backwards.
3. If you have an oscilloscope, connect channel 1 scope probe to the output of the
microBrute Modulator at J1. Verify that the pulsewidth adjustment of the
modulator is approximately from 0 to 180us. Pulsewidth should NOT exceed
200us.
4. If you have an oscilloscope, connect channel 1 scope probe to the output of the
microBrute Modulator at J1. Verify that the pulse repetition frequency (PRF)
adjustment of the modulator is approximately 50Hz to 150Hz.
Congratulations! Your microBrute Modulator is now completed and operational.

microBrute Modulator
May 2010, Rev 1 − 12 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Troubleshooting
PROBLEM: No output.
SOLUTION: Check to see that 9V battery connect is installed properly.
PROBLEM: LED is not illuminating.
SOLUTION: LED may be installed backwards.
Conclusion
We sincerely hope that you have enjoyed the construction of this Eastern Voltage
Research Kit. As always, we have tried to write this instruction manual in the easiest,
most “user friendly” format that is possible. As our customers, we value your opinions,
comments, and additions that you would like to see in future publications. Please submit
comments or ideas to:
Eastern Voltage Research, LLC
Technical Support
[e-mail]
Thanks again from the people here at Eastern Voltage Research.

microBrute Modulator
May 2010, Rev 1 − 13 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Terms and Conditions of Sale
Privacy
We do not provide any information to anyone for any reason.
Shipping
We will make every attempt to ship all orders received within 48 hours of order receipt with the exception of custom ordered
components and / or kits. This excludes weekends and holidays. Regular ground service is handled via USPS or UPS. Backorders - all
partial shipment backorders will be shipped via regular ground service at our expense.
International Orders
All foreign orders are shipped via USPS International Priority service unless otherwise noted. You are wholly responsible for any
custom duties, brokerage fees, import restrictions, etc... that are imposed after the sale.
Order Cancellations
Before you submit your order, please make sure you really want it. Once we have begun processing an order, a 25% restocking fee
will be applied, prior to any refund. If you do not agree with this policy, please do not order.
Legal Status of Products
It is the responsibility of the Buyer (not Eastern Voltage Research, LLC) to ascertain and obey all applicable local, state, and federal
laws in regard to the possession and the use of any item or kit that is offered for sale. Consult your attorney regarding local, state, and
federal laws prior to ordering. By placing an order, the buyer represents that he / she is of legal age and that the products will be used
only in a lawful manner.
Electronics Kit Limit of Liability
Our range of electronics kits are intended for educational and demonstration purposes only. They are not intended for use in
commercial applications. If they are used in such applications, the purchaser assumes all responsibility for ensuring compliance with
local laws. When a product is supplied in kit form and assembly or construction has commenced or the inner component packages
have been opened, we are unable to offer any form of refund, replacement, exchange, or free repair. This is because we cannot
guarantee the labor you provide and components can be damaged during assembly. Component packages should be checked against
the components list supplied and any shortages or damaged components must be advised to us within 7 days of delivery date to ensure
free component replacement.
It is recommended that if a kit builder does not have enough knowledge to diagnose faults, that the project should not be started unless
assistance can be obtained. (Unfortunately, an improperly installed component or bad solder joint or wiring mistake can take many
hours to diagnose and at normal service rates, the service charge could well be more than the total cost of the electronics kit.)
Mains Powered Projects
To ensure your safety, please observe these safety measures. In no way are these complete. As safety requirements vary, please check
with your local authorities, in order to comply with local requirements. If in doubt, seek the help of a qualified person.
Due to their nature and function, some electronics kits require MAINS power (115VAC) to be connected directly to the Printed
Circuit Board (PCB). Extreme care should be taken when assembling and testing these kits. MAINS power must be treated very
carefully. It is strongly recommended that you have previous experience of working with MAINS power equipment and / or circuits
prior to attempting assembly of these kits. MAINS power can cause serious injury or death and must therefore be treated with extreme
CAUTION. Construction, testing, and use of these kits should only be attempted by competent persons, and / or under the supervision
of someone fully experienced in this field.
To ensure electrical safety, and also protection from fire or personal injury, make sure your MAINS operated equipment complies
with the safety recommendations below:
- Use a suitable non-
conductive enclosure (wood, plastic, etc...) If you use a metal enclosure, be sure that the enclosure is
properly grounded to earth ground.
- Use a power switch for any device that consumes more than 10W of power. A do
uble throw switch should be utilized for
MAINS operated, transformer-less connections.
- A fuse should be utilized in series with the MAINS switch.
- Use a suitable MAINS input connector, and / or a UL three-conductor power cord which is clamped to your enclosure.
- Use properly insulated and sized wire when making any MAINS power connections inside an enclosure.
We accept no responsibility for injury, loss, or damage of any kind as a result of the purchase, assembly, or use of any of our products.
Limitation of Liability
The Customer will be responsible for ensuring the fitness for purpose of the Goods for the Customer's application. Eastern Voltage
Research, LLC accepts no liability whatsoever or howsoever arising in respect to loss, damage, or expense arising from errors in
information, or advice provided whether or not due to Eastern Voltage Research, LLC's negligence or that of its employees, agents, or
sub-contractors save for any loss or damage arising from personal injury. Eastern Voltage Research, LLC shall not be liable to the
Customer by reason of any representation (unless fraudulent), or any implied warranty, condition or other term, or any duty at

microBrute Modulator
May 2010, Rev 1 − 14 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
common law, or under express terms of Contract with the Customer, for any indirect, special, or consequential loss or damage
(whether for loss of profit or otherwise), costs, expenses, or other claims for compensation whatsoever (whether cause by the
negligence of Eastern Voltage Research, LLC, its employees or agents or otherwise) which arise out of or in connection with the
supply of the Goods or their use or resale by the Customer. The entire liability of Eastern Voltage Research, LLC under or in
connection with the Contract with the Customer shall not exceed the price of the Goods except as expressly provided in these Terms
and Conditions of Sale.
Parts Substitutions
Eastern Voltage Research, LLC reserves the right to substitute components in all electronics kits offered provided that the functional
performance of a kit is not diminished in any way.
Miscellaneous
Prices are subject to change. Product styles and parts lists may vary. New Jersey orders must add 7% sales tax. If tax exempt, please
include a resale certificate. We assume no liability associated with product usage. The buyer is liable and responsible for any loss,
damage, or expense of any kind, arising out of the use or misuse of the products. By placing an order, the buyer signifies agreement to
these Terms and Conditions of Sale.
Warranty Information
Defective Components
Its always easy to blame a component for a problem with your kit. Before you conclude that a component may be defective, please
thoroughly check your work. Today's semiconductors and passive components have reached incredibly high reliability levels, and its
sad to say that our human construction skills have not! However, on rare occasions, components which are defective may be shipped
and included in your kit. All of our kit parts carry the Eastern Voltage Research, LLC Warranty that they are free from defects for a
full ninety (90) days from the date purchase with the exception of power semiconductors (see below). Defective parts will be replaced
promptly at our expense. If you suspect a component to be defective, please mail it to us for testing and replacement. Please send only
the defective component(s), not the entire kit. The component(s) MUST be returned to us in suitable condition for testing. Please be
aware that testing can usually determine if the part was truly defective or damaged by assembly and / or usage. If you did damage or
"blow-up" a component through testing, don't be afraid to tell us. We're all human and in most cases, replacement parts are very
reasonably priced.
Power Semiconductors
Due to the nature of the kits, we cannot offer any warranty or replacement for defective or damaged power semiconductor
components. This includes both MOSFETs and IGBTs. That said, all power semiconductors are thoroughly tested prior to shipment to
ensure that you have a power semiconductor that is non-defective and in NEW, unused condition.
Missing Parts
Before assuming that a component value is incorrect, or missing, check the parts listing carefully to see if it is a critical value such as a
specific semiconductor or IC, or whether a RANGE of values is suitable (such as "10uF to 47uF"). Sometimes, a different value
component may be substituted in a non-critical application. Eastern Voltage Research, LLC electronics kits are assembled and packed
with pride in the USA. If you believe we packed an incorrect part or omitted a component clearly indicated in your instruction manual
as supplied, please contact us with information on the component so we can send a replacement as soon as possible.
Factory Repair of Assembled Kits
In the event you are having difficulty with your kit and need assistance, we do offer a factory repair service. However, to qualify for
an Eastern Voltage Research, LLC factory repair, electronics kit MUST:
- NOT be assembled with acid core solder or flux
- NOT be modified in any manner
- BE returned in full-assembled form. Kits partially assembled will not be accepted and you will lose your repair deposit.
- BE accompanied by the proper repair fee. No repair will be initiated until we have receive the MINIMUM repair fee (1/2
hour labor) of $20.00.
- INCLUDE a written description of the particular problem and legible return address inside the SAME shipping carton.
Please do not include your own hardware such as non-Eastern Voltage Research power supplies, transformers, batteries,
cables, etc... Eastern Voltage Research, LLC, reserves the right to refuse repair on ANY item in which we find excessive
problems or damage due to construction methods. To assist customers in such situations, Eastern Voltage Research, LLC,
reserves the right to solve their needs on a case-by-case basis.
The cost of repair for any kit is $40.00 per hour, regardless of the cost of the kit. Please understand that our technicians are not
volunteers and that set-up, testing, diagnosis, repair, and repacking and paperwork can take nearly an hour of paid employee time even
on a simple kit. Of course, if we find a component that was defective in manufacturer, there will be no charge to the repair of your kit.
(But please realize that our technicians know the difference between a defective component and parts burned out or damaged through
improper use or assembly.)

microBrute Modulator
May 2010, Rev 1 − 15 − © 2010 Eastern Voltage Research, LLC
microBrute Modulator Instruction Manual
Electronics Kit Return Policy
If you feel, for any reason, that you will have difficulty building any kit-based product purchased from us (and you cannot get
assistance from a friend), you can return it for a refund (minus shipping costs) provided a Return Authorization (RA) number is
obtained first from us by email. The items must be returned to use (insured against damage in transit) at the customer's expense and
received by us in original condition (with all product packaging, documentation, and a copy of the original sales invoice) within 14
days of original invoice date. The RA number must be clearly stated on the shipping carton. Kits may not be returned for any form of
refund or credit once the inner component packages have been opened or construction has been started.
Components Return Policy
Individually purchased components may not be returned for any reason. If you do not agree with this policy, please do not order.