HED designed, built and delivered four rack mounted units, each to control up to 8 ship-board Thales Power Amplifiers for United States Space and Naval Warfare Systems Command (SPAWAR).
The design required the development of a ten-layer custom circuit board based on the Coldfire processor and using Xilinx Field Programmable Gate Arrays (FPGAs), along with a custom card cage and enclosure with a fold-down front panel.
This product was designed and manufactured for Motorola SSTG. It allows
their new line of military radio transceivers to control peripheral
equipment in real time using either a 10/100 Base T or Fiber Optic
The External RF Controller is a PMC (PCI Mezzanine Card) design that
communicates with the radio transceiver via a PCI bus. It includes a
PCI bridge IC, a MPC860T PowerPC processor, 8 MBytes of Flash, 16
MBytes of SDRAM, serial EEPROM, a custom FPGA, and copper or fiber
optic Ethernet interfaces. In addition to passing Ethernet messages
between the host controller and external peripherals, this product can
format and transmit an Ethernet message in response to a changing
discrete signal faster than any product currently on the market. The
embedded software and gate array configuration are fully downloadable
via the PCI bus. This product is manufactured by HED in high volumes
|TPS-75 Transmitter Control Unit|
HED designed, built, and tested a custom Transmitter Control Unit to monitor and control the transmitter subsystems for the AN/TPS-75 Solid State Modulator Transmitter Upgrade.
The TCU is built into the door of the transmitter compartment and performs real-time analyses for each radar pulse, digitizing and analyzing the waveforms for critical signals in the transmitter, and inhibiting operation of the radar in the event of a fault. A microprocessor-based manual control panel provides back-up control in the event of the failure of the computer touch-screen.
The project involved the design of custom CCAs, control firmware, and a graphical user interface on a Linux platform, as well as the mechanical design of the door assembly.
This product is used in conjunction with the External RF Controller
shown above. The "CIA" is used as the physical interface to control
legacy military radio equipment in real time.
The CIA employs an embedded controller system similar to the External
RF Controller. It features a wide variety of I/O to communicate with
current and future equipment including RS232, RS485, Ethernet, TTL I/O,
Open collector drivers, and "FLEX I/O". The FLEX I/O is a custom
programmable I/O signal that can swing between any logic high and low
voltages between -30 and +30 VDC. The design also includes a
reconfigurable FPGA to accomodate the interface to future equipment.
The embedded software and gate array configurations are fully
downloadable via the Ethernet bus. The design is expandable and
includes an interface to an optional daughter-card that can house any
circuitry necessary to support future interfaces that can not be
supported with the current suite of on-board I/O. The CIA can be
powered from AC mains or from 10-32VDC using an external power supply.
This product is installed into an RF Power Amplifier chassis to allow
the PA to communicate with the General Dynamics DMR (Digital Modular
Radio) system via the GDDS proprietary Ethernet interface. The PEP
(Programmable Ethernet Port) board is a proven low-risk approach for
new power amplifier vendors and has already been qualified as being
compliant with the GDDS specifications in terms of timing, frequency
hopping, and proprietary Ethernet message protocol. The PEP board works
with HF and VHF/UHF PA designs.
The PEP board contains a PowerPC processor, Flash, SDRAM, FPGA,
Ethernet, and DPRAM interfaces. The FPGA provides for filtering and
processing of Ethernet messages necessary to comply with the GDDS
timing requirements for frequency hopping power amplifiers. The PEP
board communicates with the PA controller via a DPRAM interface and can
be easily incorporated into most PA designs. The PEP board requires
external 3.3V and 5.0V power and HED can design it to fit nearly any
desired board outline.
here to download the
'Ethernet PA Controller' brochure in PDF
format. (409 Kb)
|Air Defense Radar Display Consoles
This system was designed for the Taiwan Air Force (Republic of China) as a replacement for their
legacy display and control consoles. It provides display of the air traffic and Electronic Counter
Measures (ECM) threat environment, and allows for operation and control of the air defense radar system.
The system is composed of three components; a desk-configured display and control console, a server system, and an optional table-top console.
The lower display of the desk system shows the air traffic and missile-threat environment. It can display a map outline with range rings and allows the operator to pan and zoom to locate a particular aircraft or target of interest. In addition to showing the processed air traffic data it can also display up to six channels of “raw” or semi-processed radar video. It allows the operator to filter any combination of target speed, heading, height, and can filter the targets of interest from the sea and cloud clutter.
The upper display of the desk system shows the ECM (radar jamming) environment and allows the user to control all aspects of the air defense radar. The jamming environment can be shown in either 2D or 3D (jammer azimuth versus frequency versus amplitude). The upper display also contains window panes which allow for radar maintenance. One pane shows a block diagram of the radar system where an individual block becomes highlighted during fault conditions. Clicking on the individual block brings up detailed information regarding the subsystem status and faults.
Another window pane allows special maintenance functions to be performed which allows operators to monitor radar performance and adjust parameters such as antenna alignment.
The Server Rack receives data from the radar system and feeds it to multiple display/control consoles. The server is based upon a Linux PC and the server can record and playback up to 90 days worth of air traffic data. This is useful in resolving disputes between civilian and military aircraft.
The table-top console replicates the functions of the upper display of the desk console and is typically located in a central air command center.
|Radar Data Analysis Software
This software package performs aircraft tracking and statistical analyses on radar target data collected by the Hughes Air Defense Radar (HADR).
The software accesses the database of target reports generated by the radar. A sophisticated tracking algorithm converts raw target reports into aircraft tracks which are analyzed to calculate hit/miss ratios and probabilities of detection for the radar.
Range, height, and azimuth errors are calculated and used to align the radar and improve performance.
HED designs all of its software to make internationalization easy -- this software package can switch between English and Mandarin with a single button click.
The software was written in C++ for both the MacOS and Windows platforms.
|Radar Transmitter Controller
HED designed, built, and tested a custom Transmitter Control Unit to the monitor and control the transmitter subsystems for the Taiwan Hughes Air Defense Radar (HADR).
The TCU is based upon a custom data acquisition and control system paired with a COTS touch screen computer. The control system is comprised of custom digital, analog, and CPU boards all communicating over a custom backplane. An Ethernet interface provides communication between the control chassis, the touch screen PC, and an optional remote display/control console.
Radars by their nature are pulsed systems and the DSP-based analog cards can perform real-time capture-and-intercept any pulse which might stress the transmitter. The captured waveforms can be later recalled on the display during troubleshooting and maintenance operations. The digital cards monitor a myriad of input signals and can turn off power and RF to prevent damage during real-time fault conditions. The digital output signals are used for normal mode and test mode control of the transmitter subsystem.
A special built-in-test mode allows this system to fully control the transmitter during maintenance operations and a variety of front panel test points allow maintenance personnel to quickly analyze and debug transmitter problems.
The touch screen GUI allows for intuitive monitoring and control of the transmitter. The GUI shows a block diagram of the transmitter subsystem where each component becomes highlighted during fault conditions. Touching a block diagram component brings up a detailed list of status and faults which allows operators to isolate and debug problems down to the LRU level. The GUI also contains a history of status and faults which can be viewed locally or on an optional remote display/control console.
A half-rack-height door covers the control chassis and power supply during normal operation.
|Radar Antenna Monitor
This system was designed for the Taiwan Air Force (Republic of China) to monitor subsystems inside of the radar antenna.
The Antenna Monitor added comprehensive remote monitoring of subsystems inside of the HADR antenna.
Temperature, pressure, and flow rate sensors were added to monitor status of the antenna cooling system.
Programmable fault limits prevent operation in the event of a cooling system failure, and time trending is used to detect degradation of performance and trigger preventative maintenance.
A vibration monitor predicts mechanical failures in the coolant pump and heat exchanger fan to allow for preventative maintenance and reduced down time.
A companion Android application allows users to monitor the status of the antenna using a tablet device via a Bluetooth interface.
|Heat Exchanger Monitor
This system was designed for the Taiwan Air Force (Republic of China) to monitor and control two heat exchangers in the radar system.
The heat exchanger monitor samples sensor readings of flow, pressure, temperature and coolant resistivity at various locations in the cooling system and and inhibits operation of the radar in the event of a fault reading.
A touch-screen GUI enables the user to view the status of the cooling system and to control the operations of the pump, fan and chiller.
|Radar Data Converter
This system was designed for the Taiwan Air Force (Republic of China) to replace a PC based device that converts radar target reports in GFN-II format to DDL format, and to interface with the radar's Identification-Friend-or-Foe (IFF) system.
The Radar Data Converter contains an embedded Coldfire processor and interfaces to the radar system through a variety of serial and ethernet interfaces. The design includes a field-programmable gate array that implements a "de-fruiter" circuit to generate IFF video for display on the console
|Controller for Wine Industry
The Gen II Super Control is a user programmable industrial controller targeted to the wine industry. It is used to control the temperature of wine in fermentation tank as well as temperature, humidity, and CO2 levels in the areas where the wine is aged in barrels.
The controller can accommodate a variety of temperature, humidity, and CO2 sensors and provides on-off control to switch fans, pumps, humidifiers, heaters and valves. Up to five input sensors and five outputs are provided.
The control is housed in a water-proof enclosure and features a color graphics display and a non-contact capacitive sense keypad. The design uses the PIC24FJ256 processor for display control and user interface, a Cypress CY8C21434 to impement the capacitive sense keypad, and a PIC24FJ128 processor for the control algorithms.
HED designed this product for
Refrigeration Technology Inc
and has manufactured it in large quantities. The controller is in use at a number of wineries in Napa and around the world.
|Winery Control Software
Talking in real-time to all industrial controls over a Modbus interface, this software allows for master control of all tanks and climate zones in the winery. The software collects and stores all process data, logs events, and monitors alarms.
Users can be notified of alarms via text message or email, and the software serves up dynamic web pages for remote access from any smart phone or tablet device.
The software was written in C++ and is adapted to Windows, MacOS, and Linux platforms.
HED designed this software for
Refrigeration Technology Inc.
It is currently in use in a number of wineries in the Napa Valley area.
|Litecoin Mining ASIC
This custom chip implements the Scrypt algorithm used as proof-of-work required to mine the Litecoin digital currency.
The design features 128 cores each running the Scrypt algorithm for a total hash rate of 1.8 Mhash/second. The core implementation was designed using VHDL and tested on a Xilinx KC705 Evaluation board using the Kintex-7 FPGA.
HED worked with ASIC foundries to have the chip manufactured. Due to the collapse of value of Litecoin, the chip was never built. If it had been, it would have significantly out performed other Litecoin mining chips on the market at the time.
This product was designed for the electric utility industry. It allows
them to determine the phase (A, B or C) of an unknown overhead or
underground conductor in a three phase system. It is comprised of three
units; The Reference Unit, the Field Unit, and the Hotstick. The
Reference Unit gets installed (typically at a substation) on a
known-phase conductor (typically phase A). The Field Unit is the yellow
suitcase shown above and it is taken into the field where the utility
linemen touch the companion Hotstick unit to an unknown conductor. The
Hotstick sends wireless information to the Field Unit which in turn
communicates with the Reference Unit to display the phase of the probed
The Field and Reference Units both contain GPS receivers which are used
to measure the exact time between the zero-crossings of the AC voltage
waveform, where the Field Unit is connected on a known-phase waveform
to compare it against the unknown-phase waveform probed by the
Hotstick. The Field and Reference Units employ cellular and landline
modems respectively to exchange the timing information. The system can
display which phase
(A, B or C) is being probed and also the phase angle information (in
degrees) on an LCD screen on the Field Unit. For safety considerations,
the Hotstick is an inherently "ungrounded" system where the electrical
path is completed to earth ground via the tiny capacitance which exists
between the Hotstick enclosure and the earth.The Hotstick contains
microprocessor based auto-ranging circuity which allows direct contact
with voltages from 120V to 365kV.
For more information or to purchase this product contact EDM International, Inc.
|2nd Generation Phase Identification System
This product was the 2nd generation upgrade to the
Phase Identification System
designed by HED.
The 2nd generation design added a user friendly color touchscreen and graphical user interface, along with improvements to the Hotstick design, better phase identification algorithms and a digital communications link with the Reference Unit.
For more information or to purchase this product contact EDM International, Inc.
This product measures the amount of
on a high voltage power line. The amount of sag can be used to estimate
the conductor temperature so that the line capacity can be maximized.
Although HED did not originally
design this product,
HED was enlisted
to redesign the circuit boards internal to the Camera Unit and the
Datalogger Unit. The redesign effort drastically reduced the amount of
cabling and decreased the recurring cost of the product.
For more information, or to purchase this product please visit www.edmlink.com/sagometer.html.
This USB-based urology system allows physicians to quickly assess the mechanics of urinary flow and to diagnose abnormalities in voiding patterns. The HED-designed controller interfaces with uroflow and urovolume transducers, patient EMG sensors, can control a variety of fluid pumps and controls a catheter puller motor. This system complies with EN60601-1, EN60601-1-2, FCC, UL, CSA, and various other regulatory requirements.
For more information or to purchase this product contact www.Life-Tech.com.
|Wireless Uroflow Transducer
This device measures the volume and rate of urine flow and transmits the data wirelessly in real-time to the urology system computer.
HED originated the innovative enclosure design along with a custom strain gauge measurement controller with a Bluetooth communications link. The firmware features a specialized digital filter to accentuate irregularities in the urine flow rate. The firmware handles all communication protocols and controls the safe recharging of the batteries
For more information or to purchase this product contact
This product was developed for a
specializing in urology. It upgrades their older ISA based data
acquisition board to a fully plug-n-play compatible PCI based design.
This board collects data from the clients “patient
unit” for display and analysis on a PC.
This data acquisition board features
16 channels of
analog input, each
with programmable gain and offset. An analog output plus a digital data
port and a one-shot output are used to interface with the customers
external Uropump. In addition to I/O circuitry this design includes a
68HC908 processor, a PCI interface chip, and a custom CLPD design.
On-board test signal generators and an audio monitoring port aid in
system installation and calibration, and a 32K FIFO ensures continuous
data transfer over the PCI bus. HED wrote a custom Windows device
driver and INF file conforming to WDF (Windows Driver Model) standards.
HED also supplied a custom Windows GUI to aid
in product testing and
For more information please contact www.life-tech.com.
This device replaces the expensive flash bulb used to verify detonation in high explosives training sessions.
The design features a number of high brightness white LEDs and uses an inexpensive PIC processor along with an innovative circuit to reliably detect the noisy, groundless detonation signal.
This product helps evaluate the training of telephone operators or
telemarketers. The audio from up to three handsets is routed to the
TAMS unit and a central monitoring office can call the unit to listen
to any of the three handsets. Typically the monitoring office uses a PC
to autodial all of the deployed TAMS units and automatically record the
audio. That audio is then later evaluated to determine the effectivness
of the training of the operator.
The TAMS employs an embedded controller coupled with a telephone
interface and audio switching circuitry. Selecting the desired audio
channel is accomplished using DTMF signaling from the monitoring office.
This product helps real estate agents sell homes. The agent can record
a voice message describing the home for sale and the message is stored
into digital memory and is transmitted on the FM band to passing
automobile traffic. The interested home buyer tunes his car radio to
the frequency posted on the for-sale sign to hear the message.
This product is superior to competitors products because it replaces
the older unreliable tape loop with digital memory. This product
digitizes the message using CVSD encoding and stores the data into RAM.
A phase lock loop allows for precise setting of transmit frequency (88
to 108 MHz). A microcontroller handles all user input, PLL and CVSD
programming, and drives the 4-digit LED display. The RF power output is
kept low to allow FCC classification as an unlicensed transmitter. DC
Power is supplied by a Wall Cube whose power lead serves as the
The "TAG" is a motion detecting alarm system for laptop computers and
other high-dollar valuable items. It includes a keychain transmitter
and an alarm unit. Once armed, any motion will cause the alarm unit to
sound a piercing alarm tone that can only be reset using the keychain
The 315 MHz coded signal from the transmitter is decoded and validated
by an embedded microcontroller. If motion is detected while in the
armed state a 100 dB alarm tone is produced by a piezoelectric
annunciator. The wire tether attaches the alarm unit to the merchandise
and also serves as the receiving antenna. The alarm unit is powered by
a single AA battery which provides over 1 week of continuous use.
This product resides on the desk of the radio dispatcher for police,
fire, or public or private utilites and displays a four-digit numeric
ID of the person talking on the two way radio system. It is used to
uniquely identify each radio transmitter in the customers fleet of
vehicles or hand-held walkie talkies.
The ID1201 decoder processes the Motorola MDC1200 digital data burst
that accompanies the audio of the transceiver. A PIC processor is used
to decode the data stream and display the result on the four digit LED
display. The ID1201 also includes a Xilinx gate array to aid in data
decoding. The transceiver ID can also be sent to an optional printer or
serial port. The ID1201 contains an embedded real-time clock so that
the ID can be time and date stamped for printing.
For more information or to purchase this product, please visit www.controlsignal.com.
This product eliminates the need for the messy relief valve that expels
hydraulic fluid when the hydraulic actuator encounters a heavy load.
The ERV monitors the energy being consumed by the DC motor of the
hydraulic actuator and cuts off power if the motor load becomes too
great or if the integrated energy exceeds a preset threshold. The later
method of cut-off prevents motor overheating. The ERV is typically part
of a control system that includes actuator buttons (Extend and
Retract), a motor relay, and a DC power source such as a vehicle
battery. The wire supplying current to the motor is fed through the
circular torroid on the ERV which concentrates the induced magnetic
flux across a hall-effect sensor. The PIC processor monitors the hall
voltage which is in direct proportion to the current consumed by the
motor. The ERV will open the external motor relay if the load becomes
too great. The ERV can accomodate different sized motors from 20 to 100
This product controls the electronic "shutter" of a high digital CCD
video camera used primarily for microscopy.
This product incorporates a processor, high speed gate array, and
precision D/A. The companion Windows based interface allows the user to
control the Image Intensifier Gate, Gain, and Gate Delay. The Gate
(shutter duration) can vary from 20nS to 1mS and can be delayed from an
external trigger input (Gate Delay) which can vary from 0uS to 2mS in
increments of 20nS. The Intensifer Gain can be set between 2500 and
80,000 foot-lamberts-per-foot-candle to equate to a 0V to 5V output.
For more information or to purchase this product contact www.VideoScopeIntl.com
This product was designed for wind tunnel applications to accurately
measure the amount of dust or dirt which might blow across a surface.
Comprised of an infared transmitter and reciever, this product can
measure dust density over a 80dB scale (ratio of 1-to-100e6). The
infrared transmitter LED can be either pulsed or on continuously and is
controlled by circuitry housed in an enclosure shown in the bottom of
the above photo. The receiver is based on a highly sensitive and large
aperature infrared photodiode paired with a low noise logarithmic
amplifier. The vertical tube in the assembly dispenses a known amount
of "dust" and the electronic system measures the "down-wind" dust
For more information or to purchase this product contact www.cppwind.com
This device was developed for audio laboratories (and for university
physics laboratories) and allows the user to demonstrate the acoustical
properties of various materials. By placing a test material inside the
SWR resonance tube and measuring the standing wave minima and maxima,
the absorption properties of the test material can be determined.
The Audio SWR analyzer is comprised of two components: the electronics
module and the resonance tube. The electronics module contains a very
high fidelity sine wave generator which drives a speaker via a low
distortion amplifier. The speaker sets up a standing wave inside the
resonance tube where a movable microphone inside the tube can locate
the minima and maxima. The test sample is placed at the end of the tube
and, depending on its acoustical properties, changes the minima,
maxima, and phase when compared to a perfectly solid (reflective) test
sample. The signal from the microphone is processed prior to being
displayed on an analog meter. A microcontroller controls all frequency
setting, frequency counting, and 5 digit LED display updates.
This circuit board allows for custom processing of discrete I/O signals
in a Compact PCI computer system.
This product includes a Compact PCI interface and a custom gate array
which allows the user to process discrete I/O signals in a variety of
ways. It is housed on a PMC (PCI Mezzanine Card) circuit board and is
compliant with IEEE1386. This circuit board typically resides on a VME
form factor carrier.
This system allows two (redundant) computers to communicate on a single
RS232 interface. It overcomes the "one DTE per interface" limit by
incorporating bridge circuitry. The system can handle up to eight RS232
interfaces and is housed in a 19 inch rack mount panel.
This product was developed for a railroad remanufacturing company. This
circuit is part of a control loop which allows a PC computer to set the
current in an exciter coil of a DC generator.
This relatively simple analog circuit uses a precision current
monitoring technique and provides excellent linearity and temperature
stability. It is designed to be mounted inside the customers generator
Built for the electric guitar industry, the "HeadRoom" product can
greatly enhance the artistic ability of the musician.
This device restores the dynamic range which is lost when an electric
guitar is played through a distortion box. It employs precision analog
multiplier circuitry which samples the raw guitar input and varies the
distortion box output accordingly. The ratio of input to output (the
slope of the response) is adjustable to accomodate user preferences.
Other controls allow for compatibility with all types of guitar pickups
and distortion box outputs.
This device was designed and mass produced for the United States Postal
Office and is part of a vehicle identification and location system.
This circuit contains a highly sensitive motion detector whose output
is processed by an 8 pin embedded microcontroller which implements a
custom filtering algorithm that reliably declares motion in a variety
of deployment situations (parked with engine running versus actual
driving). The output is used to enable power to a cellular data link
and GPS based vehicle tracking system. The circuitry includes
automotive regulators and surge supression devices to ensure reliable
operation in an automotive enviornment.
This product was developed for the countersurvellience industry and
will "buzz" the user when a UHF or VHF body wire transmitter is
operated nearby. It is the worlds first pager sized RF detector. Also
available in a discrete black plastic enclosure.
This device is a wideband RF detector and boasts the industry's best
sensitivity of -70 dBm at 500 MHz due to a logrithmic RF detection
scheme. It contains a microcontroller which handles duty cycling of the
receiver circuits, and can run for over 2 weeks on a single AA battery.
This product was developed for Raytheon Technical Services and is used
to aid in upgrading their radar installations in Taiwan and Germany.
The I/O Transfer Panel is housed in a 1U rack mount enclosure and
allows the installer to reroute hundreds of signals and serial
interfaces using a jumper field.
The Smart Sign is a safety product that plays audible safety messages any time nearby motion is detected. It can be placed wherever a safety hazard might exist, such as on a “wet floor” sign, door knob to a quarantined room, or other location. It includes an auto-shutoff feature which turns off power after a user-preset time of 30, 45, or 60 minutes has elapsed. This allows time for the floor to dry or hazard to be removed. The auto-shutoff can be disabled for use in areas that don’t need to be timed such as on-going construction sites. The absence of the flashing white light and audio message indicates to passers-by that it is safe to enter the area.
The Smart Sign can store up to four different messages where each message can be a maximum of eight seconds in length. Each time motion is detected the recorded messages are played back, one at a time, in a rotating fashion. Multiple messages can be beneficial in multi-lingual environments. For example, message #1 could be the English Caution, Wet Floor followed by message #2 in Spanish Cuidado, Piso Mojado
A bright white light flashes every 5 seconds providing a visual indication of the nearby hazard. If only one message is recorded, that single message will be played back each time motion is detected. So as not to unduly annoy passers-by, five seconds of silence is enforced between the message(s) being played back.
This product is mounted to a generator control panel where it
continuously monitors the three phase generator output to determine
whether the stand-by generator successfully performed its periodic
auto-start self test. If the generator failed to start in the
prescribed interval an audible alarm is sounded and accompanying relay
is closed. The internal relay may be connected to a remote monitoring
system to alert maintenance personnel of the generator fault condition.
An embedded microcontroller samples the analog voltage output from the
generator and in addition to the generator start/no-start condition it
also serves as an undervoltage/overvoltage detector. The self test
interval is jumper programmable for 8/15/22/32 days and the expected
generator output is programmable for single phase or three phase
systems ranging between 120-480 VAC.
This product is currently manufactured by HED in high volume for
Transtar Products, Inc.
For more information or to purchase
The GSV300 represents a substantial technology improvement over the previous model, the GSV200. The new model features a large LCD display, easier setup, and greatly enhanced features. The GSV300 monitors a standby generator and determines whether it fails to perform it's periodic self-test. It works on any generator with voltage output between 120-480VAC and also works with “Low-RPM” or “Quiet” type generators.
This system contains an embedded microcontroller, real-time-clock, LCD display,
and analog signal conditioning. It samples the analog voltage output from the generator and utility to
determine whether the generator failed to perform it’s periodic self-test. The system also serves as a
voltmeter, frequency meter, oil change reminder, and run-time hours meter. It has four relay outputs
which can be connected to an external monitoring system to remotely inform the owner of generator health
This product is currently manufactured by HED in high volume for Transtar Products, Inc.
For more information or to purchase this product contact www.GeneratorVerifier.com.
This product was developed for a gas
and oil drilling company. The
circuit controls a latching solenoid which bleeds off accumulated water
when the water float switch reaches a predetermined height. The
solenoid open-to-close duration is adjustable between 1 and 20 seconds
using a potentiometer.
This circuit contains a DC/DC
converter, H-Bridge, and microprocessor.
The circuitry was designed to have extremely low power consumption and
will last for more than three years when powered from a standard 6V
alkaline lantern battery.
This product was developed for an
environmental engineering company.
The circuit converts the signal from an oxygen sensor to a 4-20mA
current loop signal for remote monitoring. The sensor zero and span are
adjustable using potentiometers.
HED manufactures a variety of test fixtures and test “boxes” to support our in-house projects, or as separate projects where the test equipment is designed and built per customer specifications. Test systems can be basically passive (containing only switches, connectors, controls, etc) or active (containing custom circuit boards in addition to passive circuitry).
This circuit board is a good example of HEDs capability to reverse engineer and redesign obsolete circuit boards or systems. We address obsolescence issues and redesign using current technology (the circuit board shown above was originally a wire-wrap design comprising two separate circuit boards).
This device is a high precision, rack mount, 16 channel, USB-based strain gauge measurement and data logging system. The system features programmable DSP-based filtering of the strain gauge signal so that any customer-defined filter can be implemented.
Other features include a programmable strain gauge excitation voltage of 5V, 10V, or 20V with extremely small excitation ripple, and can accommodate any strain gauge between 350 and 2000 Ohms. The amplifier gain can be varied between 1 and 10000 in 1:2:5 step increments with the resulting noise being less than 20mVp-p at max gain of 10000. Any offset inherent to the strain gauge can be zeroed using coarse and fine offset adjustment controls.
BNC outputs of the pre-filtered signal allow for external signal filtering and an optional external sample rate clock can be injected for synchronization with other subsystems. The system employs industry standard XLR connectors for the strain gauge interface.
For more information or to purchase this product contact www.cppwind.com.