John J Randall, Jr

Title: John J Randall, Jr: Innovator in Aluminum Capacitor Technology

Introduction

John J Randall, Jr. is a notable inventor based in North Adams, MA. He has made significant contributions to the field of aluminum electrolytic capacitors, holding 2 patents that enhance the performance and efficiency of these components. His work is particularly relevant in the electronics industry, where capacitors play a crucial role in various applications.

Latest Patents

Randall's latest patents include a process for treating aluminum electrolytic capacitor foil and advancements in AC etching of aluminum capacitor foil. The first patent describes a method where aluminum electrolytic capacitor foil is treated after etching but before anodizing. This process involves contacting the foil with a phosphate solution and then heat treating it to form a thermal oxide layer of controlled thickness. This thermal oxide layer modifies the barrier oxide layer during anodization, increasing its dielectric strength and capacitance while stabilizing the barrier oxide layer.

The second patent focuses on the AC etching of aluminum foil in a hydrochloric acid electrolyte containing specific additives. The presence of 200 to 500 ppm sulfate allows for etching thicker foil suitable for higher voltage applications. The chosen additives, which include phosphoric, nitric, and tartaric acids or salts, contribute to producing a foil with higher capacitance and enable the use of lower temperatures and frequencies during the etching process.

Career Highlights

Randall has been associated with Sprague Electric Company, where he has applied his innovative ideas to develop advanced capacitor technologies. His work has not only contributed to the company's success but has also influenced the broader electronics industry.

Collaborations

Throughout his career, Randall has collaborated with talented individuals such as Trung H Nguyen and Allan B McPherson. These partnerships have fostered a creative environment that has led to the development of groundbreaking technologies in capacitor design and manufacturing.

Conclusion

John J Randall, Jr. stands out as an influential inventor in the field of aluminum capacitor technology. His patents reflect a deep understanding of materials and processes that enhance the performance of capacitors, making significant contributions to the electronics industry.