. Electronic apparatus for biological research. Electronic apparatus and appliances; Biology -- Research. TRIODE charge limited conditions and cannot be made to saturate unless: (1) the cathode temperature is reduced below that intended, which we have seen to be bad; or (2) the anode voltage is excessive, which is also bad. TRIODE When Lee de Forest put a grid between the anode and cathode of a hard diode he produced the key device from which the whole technology of elec- tronics has grown up, the triode valve (Figure ). Not only does this Figure device amplify, which facilitates the de
. Electronic apparatus for biological research. Electronic apparatus and appliances; Biology -- Research. TRIODE charge limited conditions and cannot be made to saturate unless: (1) the cathode temperature is reduced below that intended, which we have seen to be bad; or (2) the anode voltage is excessive, which is also bad. TRIODE When Lee de Forest put a grid between the anode and cathode of a hard diode he produced the key device from which the whole technology of elec- tronics has grown up, the triode valve (Figure ). Not only does this Figure device amplify, which facilitates the detection of weak effects, but it does so whilst imposing a load on the effect which is for many applications quite negligible—that is, its input resistance can be made very high. This distin- guishes it from the other amplifiers used in electronics, the transductor and the transistor. At present its field of application is much wider than that of the transductor and transistor, though it is neither as robust as the former nor as small and economical in power consumption as the latter. If a triode be set up as shown in Figure , and the anode current plotted as a function of anode voltage for various values of negative grid bias, then a series of diode-like characteristic curves are produced, each one displaced further to the right as the grid bias is increased {Figure ). The mechanism \ v_ I^T + \'. reasing Figure Figure of this is that the negativity of the grid reinforces the effect of the space charge in reducing the anode current, and a higher anode voltage is necessary to achieve the same anode current. Figure is called the 'anode charac- teristic' of the valve. There are three fundamental 'valve parameters' which describe the per- formance of a triode. They are: (1) ,a, the ampUfication factor; (2) g„„ the mutual conductance; and (3) r^, the anode incremental resistance. jLi is defined as {SVjdVg)j^ and is the most nearly constant of the valve parame
Size: 1569px × 1592px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
