On Electronic Voltage Stabilizers

Abstract

Voltage stabilizing circuits employing thermionic tubes can be classified into four groups, according to their derivation from (1) the transconductance bridge, (2) the amplification factor bridge, (3) the simple degenerative amplifier, and (4) combination circuits involving two or more of the foregoing classes or utilizing amplified control voltages. It is shown that the variational performance of a stabilizer is characterized by an internal output resistance and a stabilization ratio. The effect of source resistance on these performance parameters is discussed in the general case and expressions for these parameters are evaluated for ten stabilizer circuits, seven of which are original with the authors. All but two of the circuits can be adjusted to yield perfect stabilization and four have also a very low internal resistance. Glow discharge tubes are discussed as bias battery substitutes. A simple a.c. bridge technique which is convenient for the experimental determination of stabilizer performance under normal load conditions is described in an appendix.

Electrical Characterization and Modeling of a Gelatin/Graphene System

“…The corresponding values of the open circuit voltage ( OCV ) are 0.97 V and 1.13 V for the pure gelatin and the gelatin/graphene system, respectively. According to the Thévenin theorem [8], the linear electric circuit may be represented as a series connection between an ideal voltage source OCV and the internal resistance , as shown in Figure 3.…”

Amplifier Bandwidth Estimation Techniques

“…In this section, we will estimate the high-frequency roll-off f h using OCTCs. 5 We will assume that C C and C E are so large that the low-frequency breakpoint f L is well below the high-frequency breakpoint f h .…”

“…The low-frequency roll-off is due to the coupling capacitor C C and the emitter bypass capacitor C E . 5 Later on in this chapter, we will estimate the low-frequency breakpoint f L using the method of short-circuit time constants. In this section, we will estimate the high-frequency roll-off f h using OCTCs.…”

Very simple FET amplifier with a voltage noise floor less than 1 nV/sqrt(Hz)

“…The op amp A works as a transresistance amplifier with gain R, and sets the FET transistor in a cascode configuration [8,9] (which eliminates the Miller effect [10], thus enhancing the bandwidth). The drain-source voltage V DS is set by A at the voltage V B of the polarization battery B.…”