Engineering by Technology - Power Conversion

Project

Control Electronics

Application

Diesel-Fired Military Tent Heater

Customer Need

MIL-compliant electronic control of all aspects of a military tent heater including start/stop sequence, closed-loop temperature control, fuel/air mixture, fan motor control, power management and battery charging with system power provided by a Thermo-Electric Generator (TEG). Additional requirements included a remote temperature sensor and user-set point input, with CO monitor.

AVID's Solution

Our engineering services extended beyond board and firmware design to satisfy all of the needs listed above as it included system level operational aspects, use cases, diagnostics, addressing unit to unit variations of the burners and TEGs, and corner case conditions. AVID was responsible for the complete board level design, embedded and system firmware, and system verification to Military requirements. AVID assisted in electronics packaging, cable harness design, and release to manufacturing. We also created a real-time executable for the PC that allows test engineers to monitor and modify run-time parameters during system test without the need to reprogram the system.

Value Added or Technologies Applied

System Operation and Use Case
Control Architecture
Hardware and Firmware Design and Implementation
Prototyping and Validation
PC Application Development
System Qualification Support
Manufacturing Engineering

Project

System Electronics

Application

Volumetric CT/PET/SPECT Diagnostic System

Customer Need

Electronics to detect and collect sensor data from a large photo-sensor array excited by X-rays. Unique requirements were pixel sizes eight times smaller than previous generation systems as well as a large XY array instead of the prior single slice.

AVID's Solution

In addition to the quantity and execution speed that pushed the electronic design, there were also major challenges from power, signal distribution, and thermal management that needed to be addressed. Advanced packaging was required to achieve the circuit density, and special consideration for the mechanical design included the ability to remove heat from the electronics. A mass amount of parallel signal processing was implemented as stand-alone subassemblies with dedicated ASICs, DSPs, communication interfaces to centralized memory arrays, and power conversion. The memory data on the rotor side was then organized and packed for transmission across the rotating interface and stored on the stator side for use by the post processing imaging engines. The front end processing subassemblies provided a means for modular testing and system maintenance.

Value Added or Technologies Applied

Electronic System Requirements/Architecture
Data Flow Diagrams. Memory Architecture and Management, Speed Performance Analysis
Hardware Design; Advanced Packaging Concepts (Ceramic Carriers, COB, Rigid/Flex)
In-Line Real-Time Signal Processing and Combination, VHDL and DSP Techniques
Thermal Management; Fluid-Based and Thermo-Electric Cooling
High-Speed Data Transfer Method (20GBps) Across a Rotating Interface
Proof of Concept Modeling
Manufacturing Techniques and Process Research/Definition

Project

Advanced Electronics

Application

LED Lighting

Customer Need

A sporting series of portable flashlights that combines the latest rechargeable battery technology along with high-brightness white LEDs to give consumers the next level of advanced lighting solutions. The electronics provide the dimming, spot/flood control, and battery chemistry detection, monitoring and recharging functionality. With previous designs, the light dims as the battery voltage declines, but with smart electronics, a constant current can be maintained until the battery is exhausted and needs to be recharged. The electronics need to be small and efficient to fit in a handheld package while minimizing the production cost. Recharging alternatives include AC, vehicle power, and flexible solar panels.

AVID's Solution

Incorporating a switched-mode converter technology, the LED brightness can be maintained while the battery voltage is declining. By implementing a battery gas gauge and intelligent charging algorithms, the Li-Ion batteries can be recharged quickly within safe operating conditions. A variable current limit is implemented for multiple LEDs to control the light intensity and to provide various light patterns. Special thermal techniques including metal clad boards are implemented to address the heat rise of the electronics, and specifically the LED boards.

Value Added or Technologies Applied

Microprocessor Control for LED Dimming and Smart Charging Algorithms
Switched Mode Power Conversion to Maximize Light Output even as the Battery Voltage Declines
Special Charge Algorithms for Quick and Safe Charging, as well as Optimization Depending on the Recharge Power Source
Metal Clad Boards and Other Mechanical Thermal Packaging for Heat Rise due to Concentrated Power of the LEDs
AVID Supported the Product Specification with the Client, Completed the Hardware and Firmware Design and Prototyping, Validated the Design, and Supported Introduction to Manufacturing

Project

Li-Ion Battery Control/Charger Electronics

Application

Portable Appliance

Customer Need

The consumer appliance in this case is powered from a removable battery pack which requires a charger. A spare pack may be kept charged and a quick swap allows the user to continue use. The removable pack may also be used to power different appliances. Li-Ion batteries require special care to prolong their life as well as prevent dangerous flare up. Low cost is a key driver in the design.

AVID's Solution

A low cost microcontroller was implemented to perform the battery monitoring and charging functions. Provisions for various use cases involving plugging and unplugging, erratic contact during insertion, power draw from the battery during charge cycles, and temperature monitoring for safe operation were implemented. Additionally, a communication channel was added to allow specific battery data to be transferred for status indication.

Value Added or Technologies Applied

Hardware and Firmware Architecture
Hardware and Firmware Design and Documentation
Prototype and Validation
Production Test System Development
Manufacturing Support
Manufacturing Techniques and Process Research/Definition

Project

Multi-Output Power Supply

Application

Vehicle Electronics

Customer Need

Existing customer's product was in full production. Customer requested analysis for cost reduction targeted at 30%. Base requirement for as good or better performance, and form, fit, and functional replacement. The application was a power converter used to create various supply voltages as required by an instrument cluster with stepper motors, vacuum florescent display, backlighting, and other indicator devices. The supply produces five regulated DC and a single AC voltage from the 12V vehicle bus.

AVID's Solution

AVID re-evaluated the entire design architecture and implemented a Sepic topology with tightly regulated primary outputs and secondary outputs which follow the primary regulation. All parts were carefully evaluated to determine absolute requirements and if suitable lower cost replacements could be used. Efficiency was greatly improved allowing the elimination of a large heat sink saving board space and cost. Part count was reduced by one-third with similar BOM cost savings. Regulation, ripple, step response were improved. The new design was prototyped and validated against stringent automotive standards for EMC emissions and immunity. The design surpassed the cost savings goal, as well as out performed the existing design in several areas. AVID supported the production release and pilot builds.

Value Added or Technologies Applied

Existing Design Evaluation, New Design Architecture
Hardware and Packaging Design
Prototype and Validation
EMC Testing, Design Tweaks as Required
DV, PV Support as Requested From Our Customer
Ongoing Production Support as Requested