Driving circuits

Figure 3-23 Examples of transformer-coupled base and gate drives (a) single MOSFET drive circuit (b) dual MOSEET drive.

The design philosophy behind the fixed-base drive circuit is to draw current from a relatively low voltage source (3 to 5 V) which is usually provided by an auxiliary winding on the power transformer. The resistor directly in series with the base (R2 as shown in Figure 3-33) should be on the order of 100ohms. Its... 

Figure 3-33 Fixed base drive circuits (a) quasi-totem-pole drive (b) totem-pole drive (c) transformer-coupled drive.

Figure 3-34 Proportional base drive circuits (a) the Baker clamp (b) transformer-coupled proportional base drive.

Figure 3-38 MOSFET drive circuits (a) passive turn-on (b) passive turn-off (c) bipolar totem-pole (d) MOS totem-pole (e) transformer-isolated drive.

The quartz balance is a tool for detecting the increase (or decrease) of the film mass deposited onto the surface of a quartz resonator, connected to the driving circuit, and registering the shift in a frequency. The dependence is expressed by the Sauerbray equation (Sauerbray 1964) ... 

We can never hope to converge to a valid and optimum solution if we are unwilling to do what was initially suggested develop an ability to look at any practical problem through the eyes of its supporting theory and vice versa. I think that s how I eventually succeeded. First I created a rather textbook base drive circuit (not expensive). But to do that I had to go back to first principles and educate myself further on what is the best way to drive NPN power transistors, the exact waveshape required, and so on. Then I created a balun drive, which was, I still think, a rather clever trick to produce symmetrical drive waveforms for both... 

Bao, Z. Lovinger, A. Cherniavskaya, O. 2000. Material issues for construction of organic and polymeric driving circuits for display and electronic applications. Macromolecular Symposia 154 199-207. 

The dual-function utility (photon emission in forward bias and photon detection in reverse bias) can be employed to fabricate smart display matrices [148]. By presetting the device in the photodetecting mode (zero or reverse bias), each pixel can sense an optical signal and transfer that signal to the memory in the driving circuit, similar to the process in a photodiode... 

ESD (electrostatic discharge) for integrated circuits, hard disk drives, circuit boards. Parts for high-speed electronic printing and reproduction equipment... 

ESD for integrated circuits, hard disk drives, circuit boards. .. 

One approach to achieving higher current capability is to combine several individual switches in large modules. The disadvantages of multidie modules are that the module package may introduce significant inductance, the gate drive circuit may... 

Because of its piezoelectric properties, synthetic CC-quartz is used for frequency control in electrical oscillators and filters and in electromechanical transducers. When mechanically stressed in the correct direction, CC-quartz develops an electric polarization. The opposite is also tme an applied electric field gives rise to a mechanical distortion in the crystal. Thin sections of quartz are cut to dimensions that produce the desired resonance frequency when subjected to an alternating electric field the vibrating crystal then reacts with the driving circuit to produce an oscillation that can be narrowly controlled. Quartz is ideal for this application because it is hard, durable, readily synthesized, and can be tuned to high accuracy, for example, quartz crystal clocks can be made that are stable to one part in 109. 

UC1846 50% Duty Cycle Gate Drive Circuit... 

Figure 9.1 Schematic of UC1846 fixed duty cycle gate drive circuit.

Figure 9.2 SPICE equivalent schematic of UC1846 MOSFET drive circuit.

Figure 9.5 PSpice equivalent schematic of UC1846 MOSPET drive circuit.

Figure 9.7 Schematic of pulse-shaping gate drive circuit.

The electronic control circuitry is situated in two levels below the MCB layer with the modules. It is based on a microcontroller system for the micro liquid handling and the chemical analysis data. Implemented in the electrical circuitry are driving circuits for the micro pumps, sensing circuits for the flow sensors, optical absorption measurement circuitry, power management and communications using an RS232 interface. 

In a small display it is feasible to individually connect each display element, or pixel, to an external driving circuit. As the number of display elements increases, however, the number of connections quickly becomes prohibitive. For example, a display with a resolution typical for a television set (300 X 300 pixels) would require 90,000 external connections. Matrix addressing reduces this number to 600 connections, a much more feasible number. 

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