This is an account of the Teal oil bath demonstration that was repeated many times as part of talks about the development of the new Texas Instruments silicon transistors. It was first presented by Gordon Teal at the IRE National Conference in Dayton, Ohio in 1954.
For the full history of Texas Instruments on this site please return to The Early History of Texas Instruments Semiconductors.
"On Wednesday evening, May 26, 1954, Dr. Adcock of Texas Instruments, Dallas, addressed the joint membership of the Houston Professional Chapter on Audio and the Professional Chapter on Instrumentation. The subject of Dr Adcock’s talk was the new silicon transistor, its construction, properties, and application.
The speaker presented his subject in a most lucid fashion, and the meeting was one of the highlights of this season. Dr. Adcock described, with the aid of slides, the principles underlying semi-conduction. After a review of the fundamentals of semi-conduction and the methods employed for controlled crystal growth, Dr. Adcock covered the properties of the alloy junction silicon diode.
The latter part of the program consisted of a remarkable demonstration of a five-stage, all-transistor, high impedance-input audio amplifier. A conventional crystal pickup was connected into the amplifier, and the output of the amplifier delivered a power of 250 milliwatts to a ten-inch loudspeaker, which was adequate for comfortable listening in the Southern States Auditorium.
Dr. Adcock then showed the thermal superiority of the silicon transistor over the germanium transistor. One of the silicon transistors on the amplifier was removed and inserted in an extension probe. While the amplifier was delivering full power, the transistor at the end of the probe was immersed in oil at 100 degrees C. The amplifier continued to deliver full power, with no loss in quality. The silicon transistor in the probe was then replaced b y a germanium transistor, and the same procedure repeated. As soon as the germanium transistor was immersed in the high temperature liquid, the output of the amplifier dropped to zero. When the transistor was removed from the high temperature oil, the amplifier commenced to deliver power again. The process was repeated again and again, to illustrate the superior thermal features of the silicon transistor to deliver power at high temperatures.
The meeting was extremely well attended with eighty members and guests present."
Geddes L 1954 Activities of the Houston Chapter, PGA, Audio, Transactions of the IRE Professional Group on 2 #5 131