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ELECTRONICS DESIGN
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454-7648
Rockfield
Research has decades of experience in the design of electronics for
many applications. Let us help you solve your design problems
today.
ANALOG: Precision analog circuits require attention to grounding, parasitics, op-amp characteristics, leakage currents, and more. High dynamic range sensing can require logarithmic amps, high-side sensing can require high CMRR instrumentation amps, photodiode sensing requires ultra-low bias current transimpedance amps, etc. Rockfield Research is experienced in all these techniques.
One client example at right is the Energetiq EQ-99 laser driven plasma light source - Rockfield Research designed the electronics package for this product. Active controls maintain laser current to better than 100 ppm, and laser temperature to better than 10mK, for extremely stable light output.
At high speed, other analog considerations must rule - as the physical layout becomes a transmission line circuit element.
The
Energetiq EQ-99 laser driven light source uses ultra stable laser
current and temperature control.
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This high current, high speed pulse modulator component has careful design considerations for high current, high voltage, and transmission line effects.
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This high current, high speed pulse modulator component has careful design considerations for high current, high voltage, and transmission line effects.
the Transmitter Protection System for the
MIT Plasma Fusion Center - a klystron array fault protection system
with complex analog and digital controls, embedded CPU & CPLDs, and
ethernet interface - puts it all together.
DIGITAL: Digital electronics used to be the realm of discrete gates - however discretes are rarely used now. Modern digital circuits are a mix of programmable logic, microprocessers, communications protocols, and yes, a few discretes thrown in to glue it together.
Rockfield Research specializes in control systems for scientific instrumentation - often involving multi-disciplinary designs. Digital controls are indeed the glue that hold this together. This is our bread and butter.
Click here to read more specifically on control systems, and various topologies of embedded and external control logic.
POWER: At high power, we must consider the physical impact of circuit layout. High voltages require high clearances. High currents require more copper. High speed switching power supplies are noise monsters - and require strict bypass capacitor placement, noise shielding, and considerations of ground return currents.
Above all, power means heat -- good thermal design is often crucial.
In addition to compact power systems such as the example at right, Dr. Casey of Rockfield Research spent nine years designing power modulator components for Diversified Technologies. Click here for more details of some of the projects from this era.
The Energetiq EQ-800 product - a Rockfield Research circuit design - required 32 compact buck regulators with digital controls and autocalibration. The backside of the board, shown here, had all thermally dissipative elements, and was mounted against a water-cooled heatsink.
PHYSICAL LAYOUT: Once your circuit is done, and a layout functions, you still need a working product. The constraints of physical layout cannot be understated -- the board has to fit with the product, and choices of the proper connectors can have a huge impact on the economics of the product.
We can work with your mechanical engineers, or do our own mechanical design to finish the job and make the product work.
TEST FIXTURING: We can help you design, fabricate, and test your one-off or prototype build. For production, you are going to want a test fixture. A good test fixture will.....
>>> test every subcircuit to performance specifications
>>> program & verify all cpu, flash, cplds
>>> serialize board label and/or flash memory
>>> log all test results
>>> be operable by assembly vendor's technicians
Test fixturing can be simple or complex....depending on your needs. A simple example, below, was developed for in-house use for fully testing the DSQUIRT fiber-optic isolation products
A moderate test fixture, below, is the PROG04, developed for a client product. A single pushbutton initiates a test sequence to program an embedded microprocessor and test all functionality.
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A complex test fixture, below, was developed for Energetiq to place at assembly vendor locations for the EQ-99 product. A full program/test/serialize sequence qualifies the board, scripted by a partner application on a Windows platform which logs all results.
