Sprague | Vishay Sprague
Sprague Electric was started by Robert C. Sprague in 1926 in Quincy, Massachusetts, as Sprague Specialties Company. R. C. Sprague is credited with inventing a tone control device that greatly improved the sound of radios. In 1929, the company decided to move to North Adams, Massachusetts. The move was completed in 1930.
At its peak, Sprague Electric employed 12,000 people worldwide, including over 4000 people in North Adams alone in five separate sites. The largest site (a former textile mill), called "Marshall Street," was composed of 23 different buildings, all linked by covered overpasses and tunnels. The site is now the home of Mass MoCA (Massachusetts Museum of Contemporary Art).
In the mid '60s, Sprague had plants in Scotland, France, Italy and Japan, in addition to multiple locations in the USA.
In 1976, Sprague Electric was acquired by General Cable (renamed GK Technologies in 1979). In 1981, Penn Central acquired all the stock of GK Technologies. In 1985, the Sprague North Adams operations were closed. At this time, Sprague was manufacturing a wide range of products including tantalum, aluminum, film, paper, and ceramic capacitors; resistor networks; pulse transformers; and filters. The major manufacturing sites for tantalum capacitors were located in Sanford (Maine), Concord (New Hampshire), and Tours, France.
In 1992, Vishay acquired the tantalum capacitor operations of Sprague Electric Company, while other product lines were spun off.
Vishay subsequently expanded its tantalum capacitor product portfolio by acquiring other companies and businesses, such as Roederstein (1993), Tansitor (2001), Mallory (2001), and a specialty tantalum capacitor product line from KEMET (2008).
Sprague is credited with developing the first wet tantalum capacitor in the late 1940s. At the time, these capacitors used tantalum foil as an electrode and dielectric medium with a sulfuric acid-based solution as an electrolyte. Other types were further developed using tantalum powder enclosed in a silver case. The solid tantalum capacitor was invented at Bell Labs in 1956. This type uses manganese dioxide particles as an electrolyte.
In 1975, a major improvement was made to wet tantalum capacitors with the introduction of the all- tantalum capacitor (tantalum case, tantalum cathode, and tantalum anode with glass to metal seal). This was developed for the NASA space shuttle program.
Sprague, Tansitor, and Mallory received a number of patents for tantalum capacitors. In the late 1970s, Sprague developed the first surface-mount conformal coated tantalum capacitor, the 194D (MIL style CWR06), which had metal end cap terminations. The 195D, a cost-efficient version, was developed by using plated terminations deposited by a batch process. New versions of this technology are in use today in wireless data card and module applications for laptop computers and eBook readers.
One of the most significant patents for Tansitor was for Super Tan® technology, which represented a major breakthrough in wet tantalum capacitor technology. Its unique cathode system provided the highest capacitance per unit volume. The patent for SuperTan technology was granted in 1998.
More recently, development work in the area of surface-mount tantalum chip capacitors has included Vishay's 292D Tantamount capacitor. It uses patented technology involving leadframeless terminations, enabling increased volumetric efficiency in portable electronics. This technology was greatly improved with the 298D. Based on patented technology, it combines the advantages of the 292D with high-speed packaging capabilities and efficient face-down terminations.
Sprague TVA Type Atom Axial Electrolytic Capacitors
These sturdy blue (the big ones...) or black (the little ones...) jacketed axial lead aluminum electrolytic capacitors are preferred by most craftsmen for authentic vintage guitar amp and hi-fi restorations. Many of the best sounding classic guitar amps by Fender, Ampeg, Magnatone, Valco and many others used Sprague Atom series electrolytics. Why not use 'em in your next project?