. The Bell System technical journal . Figs. 4—Some equivalent circuits. CONSTANT-CURRENTGENERATOR. HIGH-IMPEDANCEVOLTMETER Principle of measurement method. The principle of a method used for rapid measurement of the transistorimpedances is shown in Fig. 5, illustrating the measurement of forwardtransimpedance. A pair of terminals of the transistor is driven by a smallalternating current of a few thousand cycles from a high impedance gen-erator; the voltage developed is read by a high-impedance voltmeter. Bycalibrating the meter directly in ohms, one can read off the open circuitresistances of
. The Bell System technical journal . Figs. 4—Some equivalent circuits. CONSTANT-CURRENTGENERATOR. HIGH-IMPEDANCEVOLTMETER Principle of measurement method. The principle of a method used for rapid measurement of the transistorimpedances is shown in Fig. 5, illustrating the measurement of forwardtransimpedance. A pair of terminals of the transistor is driven by a smallalternating current of a few thousand cycles from a high impedance gen-erator; the voltage developed is read by a high-impedance voltmeter. Bycalibrating the meter directly in ohms, one can read off the open circuitresistances of the unit as rapidly as one can switch and read meters. Average values found by this method for the Type A transistor are shownon Fig. 6, together with data on the direct-current operating point. Since SOME CIKCL rr ASIKCTS Oi THE IKASSISlUR Hi development is still at an early stage, there are considerable variationsbetween units. Sinc;le Stage Amplifiers. ,Electron Tube Analogy An amplifier can be built in a straightforward manner by using the emitteras input electrode and collector
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
