David Johns

• Leading a high performance new product development team of 8 engineers split between Austin and India providing mentorship, and task prioritization
• Managing complex team design tasks through delegation, establishing a culture of trust, accountability, and leadership development of team members
• Fostering team collaboration through regular communication and utilization of asynchronous work management tools
• Accelerating motivation and morale by contributing a combination of expert technical guidance, passion for problem solving, compassionate leadership, and modelling personal regulation during times of stress.

• Technical product design management of novel bidirectional 30 kW AC-DC-DC power converter
• Subject matter expert; troubleshooting problematic customer grid-tied and microgrid systems; 60 - 240 kW
• Product reliability and performance enhancement; design, implementation, and validation test
• Smart inverter certification coordination UL1741SA, AS4777, FCC Part15, IEC62109, IEC61000
• Management of design implementation through remote design team in India.

• Responsible for hardware design validation and improvements related to system losses, EMC emissions, failure modes, and performance envelope
• Worked with magnetics and power semiconductor manufacturers to modify and improve component designs
• Resolved various performance, manufacturing, or design related challenges with customers, suppliers, and regulatory agencies

• Led an engineering team of 7 individuals to develop a novel grid-interactive, bidirectional 30 kW 480 Vac / 1000 Vdc, 3-port AC-DC-DC power converter
• Responsible for leadership of electrical and mechanical engineers and CAD designers
• Established and tracked new product development schedule
• Established work priorities in support of various phases of new product development
• Specified and qualified major magnetic devices
• Assigned engineering technician work priorities for R&D support and product repair

• Led an engineering team of 11 to 13 individuals consisting of electrical and mechanical engineers, CAD designers, and technicians
• Established work priorities among various projects; tracked and reported project status to senior management and to the customer
• Assisted design engineers with solving various technical problems to maintain forward progress in product development
• Developed technical proposals for new custom high voltage power conversion products including system topology proposal, cost and schedule estimates
• Worked with customers to resolve technical product and systems issues

• Developed proposals for a variety of custom high voltage power conversion products for customers in medical, semiconductor capital equipment, and X-ray security inspection markets
• Communicated with customers to clarify or refine product specifications
• Directed mechanical and electrical CAD designers, laboratory technicians, and prototype assembly personnel during product development
• Developed solutions new to the organization; validated concepts through simulation and prototype testing
• Designed test platforms and created manufacturing test procedures
• Monitored the electronic components market for leading edge products which would improve or enable new designs, and introduced many of those components to the organization

Key products designed:

• 1.5 kW, +/-25 kV four-quadrant linear high voltage amplifier for ion implanter,
• 400 W, 20 – 150 kHz, 400 – 700 ns pulse power driver for novel dielectric barrier discharge excimer flash lamp
• 4 kW, single-stage, variable output voltage, active PFC power supply for medical laser. Invented / implemented novel analog power factor controller.
• 48 kW, 6 kHz, 8 J pulsed resonant charger for excimer laser
• 57 kW, 3 kHz, 19 J pulsed resonant charger for dense plasma focus Z-pinch 13.5 nm EUV light source

• One of two-man engineering team in 'think tank' environment to develop a new high repetition rate Marx bank charging system as prime pulse power to drive magnetic pulse compression for replacement of thyratron-switched excimer laser PFNs

• Power Systems group liaison to the product system development team for the ELS-6000, ELX-7000, and XLA-100 KrF and ArF excimer photolithography laser systems
• Authored the technical specifications for the outsourced prime power converters: 1.2 kV, 12 - 14 kJ/sec cap chargers, 800 V, 36 kW reservoir chargers
• Authored the technical specifications of the outsourced pulsed resonant chargers for the ELX-7000 and XLA-100 laser systems
• Managed outsource supplier project; commissioned power module prototypes, diagnosed and resolved both module and system level issues; final production power converter module qualification

Other Significant Contributions:

• General systems troubleshooting support of both R&D and production lasers in manufacturing
• Construction and troubleshooting support of dense plasma focus Z-pinch EUV light source
• Engineering support of a 50 Billion-pulse life test of the ELS-5000 pulsed power system
• Electrical design of the control PWB of the ELS-6000 and ELX-7000 commutator power modules
• Development of an analog timing compensation circuit for the magnetic pulse compression systems