Voltage feedback

Now the component values can be calculated. The value of the input resistor (Rl) is known since it is the upper resistor in the feedback voltage divider. The value of the feedback components are found as follows ... 

Fig. 3. Optimal current fluctuations (left panel) and feedback voltage (right panel) versus time for different conductors and different values of 7th//f. Each line corresponds to one point on the curves in figure 2. Note the different voltage scales. The labels stand for (branch ith/7f) (a) b+ l/5, (b) b+ l/10, (c) t- 1 /3, (d) d- 1 /3, (e) d- 2/3, (f) t- 2/3.

Two different modes of imaging have been developed the constant current mode and the constant height mode. In the first experiment, the tip is scanned across the surface at constant tunnel current /T, maintained at a pre-set value by continuously adjusting the vertical tip position with the feedback voltage Vz. In the case of an electronically homogeneous surface, constant current essentially means constant tip-sample distance z (Fig. 7). 

The values of acoustic power obtained were correlated with the values of oscillation amplitude of an ultrasonic radiator. The latter were obtained using feedback detectors and valve voltmeter. In the following experiments, the values of feedback voltage give an opportunity to indicate the values of acoustic power at which the melt starts to cavitate. A decrease in acoustic power introduced in the... 

A constant-temperature Wheatstone bridge is shown in Fig. lb. The circuit bridge is balanced in advance under no-flow conditions using the variable resistor R2. Therefore, with the flow of the fluid, the hot wire or film is cooled, and its resistance decreases and unbalances the bridge. A differential amplifier would then balance the bridge with a feedback voltage [4]. Such electrical output correlates directly with the flow rate. 

The inductance of the lead common to both the output and input circuits has the desirable feature of providing voltage of opposite polarity to neutralize the feedback voltage of the residual plate to control grid capacitance of the tube. It should be noted, however, that the mutual coupling from the screen lead to the input resonant circuit may be a possible source of trouble, depending on the design. 

FIGURE 10.131 Common-stator UPS m-g set. The firing angle of the SCR inverters is determined by a feedback voltage from the generator output. 

Feedback is also used to provide a constant (controlled) voltage as shown in Figure 7.34. is the controlled voltage. The output is sampled by the voltage-divider network of and R2 and the feedback voltage Vj- is compared against a reference V. ... 

The amplitude of the DC (feedback) voltage,, that determines the frequency,, of the oscillator is equal to... 

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