INNOVATIVE MINDS exist in all competitive categories of our
hobby/sport. Finding out about new “stuff” is a particularly enjoyable
aspect of being a columnist. Many times the innovations come from
individuals who solve a problem. They do not stop there, however; they
continue to develop their idea and turn it into a product.
Many of the products I use today to start my glow engines did not
exist when I began flying RC in the early 1970s. Individuals developed
products that are now the flight-box “standard” for most of us, such as
battery-driven systems to electronically diagnose and light our glow
plugs and cordless electric starter motors to turn over our balky engines
and save our fingers in the process.
A great deal of new thinking is continually being applied to our
onboard flight systems, not the least of which is regarding the on/off
switch and the control of the batteries needed to keep our receivers and
servos operating safely.
Ed Alt is a longtime RC pilot who has built and flown International
Miniature Aerobatic Club (IMAC) and RC Aerobatics (Pattern)
airplanes. He has competed in both categories on the national AMA
level.
One area Ed has always felt could be improved is switch and battery
management in the RC airplane. He wanted to make a reliable switch
that, if it failed physically, would leave the receiver system turned on!
He also wanted a regulator system that would manage multiple and
backup batteries. Ed recommends that regardless of the switching and
regulator selected, we use the “right” batteries with the correct voltage
and capacity ratings to deliver current under the loads created by
multiple high-torque digital servos.
Ed also identified that you need to select a regulator system with a
high-reliability design, preferably with a fail-safe switch. Then he saw
the need to precisely program such niceties as low dropout ratings, fast
response to load demands, and high current-delivery capabilities. He
also wanted to prevent and provide protection against any reverse
current flow between the different capacity levels of two batteries in the
same system.
Ed met his own challenge by designing a programmable voltage
regulator with a fail-safe switch system that has all the key features to
meet the preceding requirements. Following, in Ed’s words, is a more
comprehensive and technical description of how his product works.
“Tech-Aero Designs offers a precision fail-safe/backup switch that
was designed with the RC Pattern and IMAC flier needs in mind. While
preparing for the arrival of two new Prestige Pattern airplanes for the
2006 contest season, I had exhausted my search for an off-the-shelf
regulator solution for a lightweight dual battery system.
“At a minimum I needed a simple, reliable system that would
provide a balanced flow of current from each of two Li-Poly batteries
simultaneously. None of the available fail-safe switch type of voltage
regulators would allow me to select from a range of output voltages to
fine-tune my setup in a way that would optimize servo speed and power
and still have enough precision to let each of the two batteries draw
down at similar rates during use while providing the safety backup in
case one should ever fail.
“In checking around with some top fliers in the NSRCA [National
Society of Radio Controlled Aerobatics] District 1 region, I found that I
was not the only one with that need. The only solution was to build my
own regulator system, thus the Tech-Aero Designs FlexReg was born.
“At first, there was no particular plan to go into business to sell these
units. I built 30 to divvy up between myself and my local Pattern friends
Also included in this column:
• NSRCA’s new slate of
officers
B e l o w : T e c h - A e r o
Designs’ new FlexReg
fail-safe switch can drive
two regulated batteries
and keep them balanced
at the same time.
Receiver switch works opposite of what you would expect. The off position turns on
power. The on position disengages all power. If switch fails the receiver stays on, hence
fail-safe.
Two light two-cell 900 mAh Li-Poly
batteries installed side by side and
connected to the balancing/regulator and
redundancy circuit.
“Tech-Aero Designs offers a precision fail-safe/backup switch that
March 2007 105
Derek Koopowitz of Benicia CA with his
first X-Treme Composite Astral-XX, at
the 2005 AMA Nats in Muncie IN.
The later and current Astral-XX Plus with
an anhedral tail, on the right, is shown
alongside its predecessor.
who expressed an interest. They’re now competition tested and have
fully lived up to the expectation that was set for their performance and
reliability.
“The product offerings from Tech-Aero Designs include
production versions of the original FlexReg, as well as a dual
redundant regulator that combines everything into one lightweight
and compact package that operates from a single switch.
“The FlexReg can also be used in a single battery, single regulator
solutions, since its 5A peak current output has more than enough
capability to handle any size Pattern airplane with ease.
“The main purpose of a fail-safe switch and dual redundant battery
system is to protect against loss of control due to the failure of a
battery or a switch harness. Mechanical switch contacts are much
more prone to failure than electronic switches.
“The idea that is employed by the FlexReg, as well as some other
regulators, is to use the switch to turn the regulator off when the
switch contacts are closed [external switch in the on position turns off
the battery power], thus eliminating the possibility of a failed contact
causing a loss of power to your receiver, etc.
“No current flows through the external switch when the regulator
is on and supplying power to the servos. In fact, the FlexReg will
operate without any switch attached at all! This is preferred by some
fliers with electric motor setups, since they are always reaching inside
to plug/unplug batteries anyway.
“With a dual battery setup, each regulator’s voltage output must be
set and maintained very closely to the other. If one is set just a small
fraction of a volt higher than the other, it will always be favored and
thus supply the bulk of the battery current.
“The key feature that makes the FlexReg unique for redundant
battery applications is its very precisely programmable voltage
output. Each regulator can be set to one of 32 different output
voltages in a range from 5.75 to 6.65, which lets you get them close
enough to achieve the goal of a well-balanced shared load.
“In the event that something does fail, the other regulator and
battery continue to supply the full load needed without the slightest
interruption and at the same voltage level. This happens without any
reverse flow into the failed battery since that path is completely
blocked by the regulator circuitry.
“The FlexReg is ready to run to fit most needs as supplied. For
different voltages, etc. it can be easily reprogrammed. There is a
programming port that connects to an optional programmer and
digital voltmeter (the E-Z Set). The E-Z Set port is also very useful
for preflight battery voltage checks via the battery/DSC port.
“The programming procedure is simple; just plug the regulator
output to the E-Z Set and then plug the programming lead into the
programming port. With the regulator switched on, you just “tap”
either the up or down programming button to make a change, which is
immediately shown on the digital display. To save the new setting,
you just turn the regulator off or disconnect it from the battery. It’s
that easy!
“The FlexReg is designed for a two-cell Li-Poly or Li-Ion battery
pack application. It will work just as well in five- and six-cell Ni-
Cd/NiMH battery applications.
“A Quick Start manual provides the key information to get going
right away. For those with more of a curiosity in the details, a full
manual is also downloadable at www.tech-aero.net.
“There is also a Tech-Tips section, which has a write-up to
explain redundant battery techniques in detail, including how to
easily reconfigure two regulators (or one dual regulator model) to
employ a ‘hot standby’ battery backup, which purposely holds the
spare battery in reserve, to come on line instantaneously if the
primary ever fails.”
The Tech-Tip makes for persuasive reading for why we should all
have a rock-solid redundant power-delivery system in our model
aircraft. Even though you can successfully fly with just one battery
and regulator, having a high-availability backup in case of battery
failure is great insurance.
The NSRCA, which is the AMA Pattern SIG, recently had an
unopposed election for the 2007-2008 national offices. For the next
two years Derek Koopowitz of California will be the NSRCA
president. He is a former NSRCA treasurer and is well versed in the
NSRCA Pattern SIG business.
Ron Van-Putte of Florida returns as the NSRCA vice president.
He is a former NSRCA vice president with many valuable years of
NSRCA and Nats experience. The two “rookies” are NSRCA
Secretary Jim Quinn from upstate New York and new NSRCA
Treasurer Ron Davies of California.
On the subject of Derek Koopowitz, I have the details of his
exciting new Astral-XX. This version of the model debuted in 2005,
and Tetsuo Onda of Japan flew it to a second-place finish at the 2005
F3A World Championships in France.
This model is the latest in a series of designs from Giichi Naruke
that have been proven repeatedly in competition. The airplane’s
specifications are: fuselage length, 1.97 meters; wingspan, 1.99
meters; weight, 4.7-4.9 kilograms.
Derek reports that there has been an additional upgrade to the XX,
and it is now called the Astral-XX Plus. The differences are in the
wing and the vertical fin/rudder. The wing is slightly smaller than the
XX’s and the fin shape is slightly different. In addition, the stabilizer
is configured win some anhedral.
Derek received his Astral-XX in January 2005 and said that it is
by far the best airplane he has ever flown. He got his model directly
from XTreme Composites in Thailand, but they are now being
imported into the US by Bob Violett Models at www.bvmprops.com.
This aircraft is extensively prefabricated and molded in a
lightweight vacuum sandwich composite and comes fully painted.
The Astral-XX has a one-piece wing and comes with a complete set
of fuselage and wing/stabilizer covers.
All Derek needs now is an Ed Alt Tech-Aero Designs FlexReg to
keep his investments supplied with battery power. MA
Edition: Model Aviation - 2007/03
Page Numbers: 104,105
Edition: Model Aviation - 2007/03
Page Numbers: 104,105
INNOVATIVE MINDS exist in all competitive categories of our
hobby/sport. Finding out about new “stuff” is a particularly enjoyable
aspect of being a columnist. Many times the innovations come from
individuals who solve a problem. They do not stop there, however; they
continue to develop their idea and turn it into a product.
Many of the products I use today to start my glow engines did not
exist when I began flying RC in the early 1970s. Individuals developed
products that are now the flight-box “standard” for most of us, such as
battery-driven systems to electronically diagnose and light our glow
plugs and cordless electric starter motors to turn over our balky engines
and save our fingers in the process.
A great deal of new thinking is continually being applied to our
onboard flight systems, not the least of which is regarding the on/off
switch and the control of the batteries needed to keep our receivers and
servos operating safely.
Ed Alt is a longtime RC pilot who has built and flown International
Miniature Aerobatic Club (IMAC) and RC Aerobatics (Pattern)
airplanes. He has competed in both categories on the national AMA
level.
One area Ed has always felt could be improved is switch and battery
management in the RC airplane. He wanted to make a reliable switch
that, if it failed physically, would leave the receiver system turned on!
He also wanted a regulator system that would manage multiple and
backup batteries. Ed recommends that regardless of the switching and
regulator selected, we use the “right” batteries with the correct voltage
and capacity ratings to deliver current under the loads created by
multiple high-torque digital servos.
Ed also identified that you need to select a regulator system with a
high-reliability design, preferably with a fail-safe switch. Then he saw
the need to precisely program such niceties as low dropout ratings, fast
response to load demands, and high current-delivery capabilities. He
also wanted to prevent and provide protection against any reverse
current flow between the different capacity levels of two batteries in the
same system.
Ed met his own challenge by designing a programmable voltage
regulator with a fail-safe switch system that has all the key features to
meet the preceding requirements. Following, in Ed’s words, is a more
comprehensive and technical description of how his product works.
“Tech-Aero Designs offers a precision fail-safe/backup switch that
was designed with the RC Pattern and IMAC flier needs in mind. While
preparing for the arrival of two new Prestige Pattern airplanes for the
2006 contest season, I had exhausted my search for an off-the-shelf
regulator solution for a lightweight dual battery system.
“At a minimum I needed a simple, reliable system that would
provide a balanced flow of current from each of two Li-Poly batteries
simultaneously. None of the available fail-safe switch type of voltage
regulators would allow me to select from a range of output voltages to
fine-tune my setup in a way that would optimize servo speed and power
and still have enough precision to let each of the two batteries draw
down at similar rates during use while providing the safety backup in
case one should ever fail.
“In checking around with some top fliers in the NSRCA [National
Society of Radio Controlled Aerobatics] District 1 region, I found that I
was not the only one with that need. The only solution was to build my
own regulator system, thus the Tech-Aero Designs FlexReg was born.
“At first, there was no particular plan to go into business to sell these
units. I built 30 to divvy up between myself and my local Pattern friends
Also included in this column:
• NSRCA’s new slate of
officers
B e l o w : T e c h - A e r o
Designs’ new FlexReg
fail-safe switch can drive
two regulated batteries
and keep them balanced
at the same time.
Receiver switch works opposite of what you would expect. The off position turns on
power. The on position disengages all power. If switch fails the receiver stays on, hence
fail-safe.
Two light two-cell 900 mAh Li-Poly
batteries installed side by side and
connected to the balancing/regulator and
redundancy circuit.
“Tech-Aero Designs offers a precision fail-safe/backup switch that
March 2007 105
Derek Koopowitz of Benicia CA with his
first X-Treme Composite Astral-XX, at
the 2005 AMA Nats in Muncie IN.
The later and current Astral-XX Plus with
an anhedral tail, on the right, is shown
alongside its predecessor.
who expressed an interest. They’re now competition tested and have
fully lived up to the expectation that was set for their performance and
reliability.
“The product offerings from Tech-Aero Designs include
production versions of the original FlexReg, as well as a dual
redundant regulator that combines everything into one lightweight
and compact package that operates from a single switch.
“The FlexReg can also be used in a single battery, single regulator
solutions, since its 5A peak current output has more than enough
capability to handle any size Pattern airplane with ease.
“The main purpose of a fail-safe switch and dual redundant battery
system is to protect against loss of control due to the failure of a
battery or a switch harness. Mechanical switch contacts are much
more prone to failure than electronic switches.
“The idea that is employed by the FlexReg, as well as some other
regulators, is to use the switch to turn the regulator off when the
switch contacts are closed [external switch in the on position turns off
the battery power], thus eliminating the possibility of a failed contact
causing a loss of power to your receiver, etc.
“No current flows through the external switch when the regulator
is on and supplying power to the servos. In fact, the FlexReg will
operate without any switch attached at all! This is preferred by some
fliers with electric motor setups, since they are always reaching inside
to plug/unplug batteries anyway.
“With a dual battery setup, each regulator’s voltage output must be
set and maintained very closely to the other. If one is set just a small
fraction of a volt higher than the other, it will always be favored and
thus supply the bulk of the battery current.
“The key feature that makes the FlexReg unique for redundant
battery applications is its very precisely programmable voltage
output. Each regulator can be set to one of 32 different output
voltages in a range from 5.75 to 6.65, which lets you get them close
enough to achieve the goal of a well-balanced shared load.
“In the event that something does fail, the other regulator and
battery continue to supply the full load needed without the slightest
interruption and at the same voltage level. This happens without any
reverse flow into the failed battery since that path is completely
blocked by the regulator circuitry.
“The FlexReg is ready to run to fit most needs as supplied. For
different voltages, etc. it can be easily reprogrammed. There is a
programming port that connects to an optional programmer and
digital voltmeter (the E-Z Set). The E-Z Set port is also very useful
for preflight battery voltage checks via the battery/DSC port.
“The programming procedure is simple; just plug the regulator
output to the E-Z Set and then plug the programming lead into the
programming port. With the regulator switched on, you just “tap”
either the up or down programming button to make a change, which is
immediately shown on the digital display. To save the new setting,
you just turn the regulator off or disconnect it from the battery. It’s
that easy!
“The FlexReg is designed for a two-cell Li-Poly or Li-Ion battery
pack application. It will work just as well in five- and six-cell Ni-
Cd/NiMH battery applications.
“A Quick Start manual provides the key information to get going
right away. For those with more of a curiosity in the details, a full
manual is also downloadable at www.tech-aero.net.
“There is also a Tech-Tips section, which has a write-up to
explain redundant battery techniques in detail, including how to
easily reconfigure two regulators (or one dual regulator model) to
employ a ‘hot standby’ battery backup, which purposely holds the
spare battery in reserve, to come on line instantaneously if the
primary ever fails.”
The Tech-Tip makes for persuasive reading for why we should all
have a rock-solid redundant power-delivery system in our model
aircraft. Even though you can successfully fly with just one battery
and regulator, having a high-availability backup in case of battery
failure is great insurance.
The NSRCA, which is the AMA Pattern SIG, recently had an
unopposed election for the 2007-2008 national offices. For the next
two years Derek Koopowitz of California will be the NSRCA
president. He is a former NSRCA treasurer and is well versed in the
NSRCA Pattern SIG business.
Ron Van-Putte of Florida returns as the NSRCA vice president.
He is a former NSRCA vice president with many valuable years of
NSRCA and Nats experience. The two “rookies” are NSRCA
Secretary Jim Quinn from upstate New York and new NSRCA
Treasurer Ron Davies of California.
On the subject of Derek Koopowitz, I have the details of his
exciting new Astral-XX. This version of the model debuted in 2005,
and Tetsuo Onda of Japan flew it to a second-place finish at the 2005
F3A World Championships in France.
This model is the latest in a series of designs from Giichi Naruke
that have been proven repeatedly in competition. The airplane’s
specifications are: fuselage length, 1.97 meters; wingspan, 1.99
meters; weight, 4.7-4.9 kilograms.
Derek reports that there has been an additional upgrade to the XX,
and it is now called the Astral-XX Plus. The differences are in the
wing and the vertical fin/rudder. The wing is slightly smaller than the
XX’s and the fin shape is slightly different. In addition, the stabilizer
is configured win some anhedral.
Derek received his Astral-XX in January 2005 and said that it is
by far the best airplane he has ever flown. He got his model directly
from XTreme Composites in Thailand, but they are now being
imported into the US by Bob Violett Models at www.bvmprops.com.
This aircraft is extensively prefabricated and molded in a
lightweight vacuum sandwich composite and comes fully painted.
The Astral-XX has a one-piece wing and comes with a complete set
of fuselage and wing/stabilizer covers.
All Derek needs now is an Ed Alt Tech-Aero Designs FlexReg to
keep his investments supplied with battery power. MA