Gained output ratio

Efficiency to gain higher input/output-ratio by utilize synergistic effects. 

Power gain A ratio of the output power to the input power. The ratio can be expressed by a number, in decibel, or in neper. 

GAIN The ratio of the amplitude of the output signal of an ampler to the amplitude of its input signal. 

The gain (amplitude ratio AR) is the ratio between the amplitude of the input signal and output signal of a transfer function G(fi>). This is equal to the norm of the transfer function ... 

In the second development, the emphasis is on taking advantage of the increa.sed specific work associated with evaporative intercooling and of the increased mass flow and work output of the turbine. Any gain on the dry efficiency is likely to be marginal, depending on the split in pressure ratio. 

In some commercial devices, the proportional gain is defined as the ratio of the percent controller output to the percent controlled variable change [%/%]. In terms of the control system block diagram that we will go through in the next section, we just have to add gains to do the unit conversion. 

The overall ability of a power supply to attenuate disturbances at its input is expressed as its PSRR (power supply rejection ratio). In graphs, PSRR is usually plotted as a function of frequency. We will invariably find that the rejection ratio is very low at higher frequencies. One reason for this is that the Bode plot cannot really help because the open-loop gain is very small at these frequencies. The other reason is, even a tiny stray parasitic capacitance (e.g., across the power switch and inductor) presents such a low impedance to noise frequencies (whatever their origin) that almost all the noise present at the input migrates to the output unimpeded. In other words, the power stage attenuation (which we had earlier declared to be Vo/Rin) is also nonexistent for noise (and maybe even ripple) frequencies. The only noise attenuation comes from the LC filter (hopefully). 

The ratio of the change in the steadystate value of the output divided by the magnitude of the step change made in the input is called the steadystate gain of the process K,. 

The steadystate gain is the ratio of output steadystate perturbation over the input perturbation. 

The stead ystate gain Kp is easily obtained from the ratio of the final steady state change in the output Sx over the size of the step input Am. The deadtime can be easily read from the x, curve. The time constant can be estimated from the time it takes the output to reach 62.3 percent of the final steadystate change. 

The steadystate gain of the transfer function is G(o> or just the ratio of the areas under the input and output curves. 

Such amplifiers are commonly used with a feedback connection curve B of Figure 7.3 illustrates the relation between input and output for a ratio of feedback resistor Rfto input resistor Rj of Equation 7.10. Under this condition, a gain of -10 is obtained to about f = 10 kHz, beyond which the gain drops and the phase lag commences. The same results would be obtained with the control circuit of Figure 7.1 if Rs/Ru = 10 and if Cdl is shorted. Curve B can be calculated from the equation... 

Thus, the signal gain depends upon the ratio Rf/R. Figure 6.626 represents a buffer amplifier or voltage follower in which V0 = V,. This has the high input and low output impedances necessary to obviate the kind of inter-element loading problems illustrated in Section 6.11.6. For a more detailed treatment the reader is referred to Smith 881. 

Consider the control loop shown in Fig. 7.44. Suppose the loop to be broken after the measuring element, and that a sinusoidal forcing function M sin cot is applied to the set point R. Suppose also that the open-loop gain (or amplitude ratio) of the system is unity and that the phase shift xj/ is -180°. Then the output JB from the measuring element (i.e. the system open-loop response) will have the form ... 

The output of the element represented by equation 7.155 lags the input. However, the destabilising effect of this additional lag is more than offset by an associated decrease in amplitude ratio. This decrease is more pronounced as the difference between r, and tj is increased. Lag compensators can be designed to produce different total open-loop stability specifications (e.g. in terms of allowable gain margin, phase margin, etc.) in a manner similar to that for lead compensators. 

The steady-state input/output relationship for a hearing-aid compressor is shown in Fig. 6.14. For input signal levels below the compression threshold, the system is linear. Above the compression threshold, the gain is reduced so that the output increases by 1/CR dB for each dB increase in the input where CR is the compression ratio. 

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