Passive output stages

The passive output stage is the traditional passive, semieonduetor reetifier-based design. It is used for many applieations that are not battery operated, and where switehing power supply effieieneies of between 72 and 84 pereent are aeeeptable. This would inelude many off-line applieations where the heat generated by the supply is easily handled within the power supply. 

The facilitation of entry into hypnosis by muscle relaxation and immobility is mirrored by sleep onset. Control of the motor system must be abandoned by subjects wishing to abet either process. This at first passive deactivation of the motor system can proceed to frank paralysis in the deepest stages of trance and emergent REM sleep when the active inhibition of motor output is instantiated. The suppression of movement in deep hypnotic trance appears to be caused by extreme defacilitation of motor networks rather than active inhibition, and hence it can be overcome by strong stimulation and strong effort. 

One simple approach has been that of Cole et al. who propose the use of two sensors run in a ratiometric mode [12]. Figure 9 shows a CMOS chip that drives a pair of resistive odour sensors one polymer sensor is active while the other is passivated. The output of the ratio of the resistances is amplified rather than the absolute resistance of just one sensor. This removes at the input stage of the amplifier any common mode signals, such as temperature drift. 

In the circuit, the analogue stage replaces the passive filter, which is often required by switching amplifiers. That is, it performs the tasks of an analogue filter at the power level. The ripple of the output signal of the switching amplifier can be dampened by more than 20 dB. A passive coil filter usually... 

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