Integrators, current feedback

Mahattanakul, L, and Toumazou, C. 1996. A theoretical study of the stabihty of high frequency current feedback op-amp integrators. IEEE Trans, on Circuits and Systems I, Vol. 43, No. 1, pp. 2-12. 

As a specific example to study the characteristics of the controller, the problem involving four modes of longitudinal oscillations is considered herein. The natural radian frequency of the fundamental mode, normalized with respect to 7ra/L, is taken to be unity. The nominal linear parameters Dni and Eni in Eq. (22.12) are taken from [1], representing a typical situation encountered in several practical combustion chambers. An integrated research project comprising laser-based experimental diagnostics and comprehensive numerical simulation is currently conducted to provide direct insight into the combustion dynamics in a laboratory dump combustor [27]. Included as part of the results are the system and actuator parameters under feedback actions, which can... 

Fig. 11.5. A schematic of the feedback loop in an STM. The tunneling current, after the current amplifier and the logarithmic amplifier, is compared with a predetermined voltage, which represents the current setpoint. The error signal is processed by the feedback electronics, which typically contains an amplifier and an integration circuit. The output of the feedback electronics is applied to the z piezo, to keep the error between the actual tunneling current and the reference current very small. The voltage applied to the z piezo is recorded as the topographic image.

Figure 3. ITC-measurement of the complexation of (-)camphor by a-cyclodextrin in water. Left Primary heat pulse trace (CFB = cell feedback current) the saw-tooth shape arises from changing the aliquots of titrand solution. Right The time integral of the heat pulses furnishes the titration curve. The solid line represents the best fit to a 2 1 host-guest sequential binding model.

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