In an attempt to increase the stable sensitivity of the direct current amplifier designed by Voorhis, it developed that the commercial tube, type 2A6, is particularly suited to such work. A single 2A6 in a circuit similar to that of Sallu gave a sensitivity of 3xl0-3 amps/mm. with a galvanometer of sensitivity, 10-8 amps/mm. An arrangement with a portable microammeter and an a.c. power supply resulted in a useful portable high impedance galvanometer with a sensitivity of 10-11 amps/mm. The circuit is discussed and methods of balancing explained. It is shown that adjustments are not critical and the amplifier is sufficiently stable.
Proceedings of the Iowa Academy of Science
©1935 Iowa Academy of Science, Inc.
Huntoon, R. D.
"An Inexpensive Direct Current Amplifier,"
Proceedings of the Iowa Academy of Science, 42(1), 151-151.
Available at: https://scholarworks.uni.edu/pias/vol42/iss1/60