Effective input

For 4-20 milliamp inputs, the resolution is not quite as good as stated above. For a 12-bit bipolar A/D converter, 1-volt converts to a digital value of 400. Thus, the range for the digital value is 400 to 2000, making the effective input resolution 1 part in 1600, or 0.0625 percent. 

Bolus administration is usually characterized by a normalized injection function that effectively inputs the dose in a bell-shaped curve manner. Since bolus administration is not instantaneous, this approach is considered more realistic. I(t) for bolus administration is... 

The effective input resistance of a DC amplifier may be greatly increased by the use of negative feedback. This principle is illustrated for charge measurement in Fig. 7.4, where a feedback capacitor is connected across an amplifier with k high input resistance Rm and gain —N. To make a measurement, the amplifier is first unshorted whilst the input probe faces an earthed shield. The shield or cap is then removed and the probe taken near to the charged surface in... 

The effective impedance of media 2 (or the effective input impedance at the boundary) is represented in a similar manner, but with the angle of transmission in media 2, < 2 replacing y These two angles are related by Snell s law (which might be familiar from geometric optics) ... 

If we look into the gate, from the viewpoint of the ac drive signal, the effective input charging capacitance is the parallel combination (arithmetic sum) of Cgs and Cgd. We are going to call this simply the gate or input capacitance Cg in our discussion. So... 

An alternative system of writing the capacitances is in terms of the effective input, output, and reverse transfer capacitances — that is, Ciss, Crss, and Coss respectively. These are related to the interelectrode capacitances as follows... 

Basically, we are using the gate charge factors to tell us what the effective capacitances are (and the voltage swings from 0 to Vin). We see that the effective input capacitance (Ciss), for... 

Note that the voltage source must be able to supply the input current, so that the effective input impedance of the whole circuit is R. Typical values are 1 to 100 kfi. 

There is very little loading effect of the current follower circuit. Because the input current source is connected between point S and arinmon and point 5 is kept at virtual common, the input-signal. source senses virtually zero resistance at its output terminals. The effective input resistance R, is the error voltage divided by the input current, i, that is, / , -- v ii.. Because - c,.M atid from Equation 3-4/, - -i jR,. we can write... 

A PE has one or more inputs. If the PE is not in the input layer, these inputs are the outputs of other PEs and will have weights associated with them. The first step in PE operation is to sum the inputs with a summation function. The result of the summation function may be thought of as the effective input to the PE. This effective input is then transformed via a transfer function, which depends on the effective input and an arbitrary but adjustable parameter typically referred to as gain. (In some instances, noise may be added to the effective input to a PE before the transfer function is applied. Typically a random number within a specified range is added to the effective input to each PE within a layer. The distribution of random numbers is either uniform or Gaussian.) The result of transformation, T, is then scaled linearly according to... 

We have used the phrase winning PE rather glibly, without explaining what it means. Usually the PE with the largest value of T in a layer is the winning PE. However, if the Euclidean distance or city block distance summation function is used, the opposite holds true, that is, the PE with the smallest value of T, is the winnen These summation functions are usually used with special-purpose transfer functions (an example is a radial basis transfer function), which perform a monotonic inversion of the effective input. ... 

Fortunately, the bandwidth-dictated load resistance, R, can be supplied by the amplifier and the net noise decreased substantially because of the gain in the amplifier first stage. One of the preferred amplifier types is the transimpedance amplifier, which presents an appropriate input resistance using negative feedback, but has an equivalent input noise current smaller than that of a real resistor. Commercial low noise amplifiers for optical detection are usually characterized by an effective input noise current, sometimes called the spot noise current, (/ )usually quoted in pA/VHz, with 1 pA =10 A. Since the amplifier now includes the load resistance, R, of Fig. 2(b), its contribution is included in the effective input noise current. The amplifier limited noise equivalent power, NEPal, is then... 

Fig. 4. Impedance converters for measuring e.m.f. of a cell, (A) using a voltage follower (the effective input resistance, equals the common mode resistance of an FET-type operational amplifier), (B) using voltage feedback (Reff R-Ao, where R is the input resistance, Aq is the OA gain without feedback), (C) by means of an instrumentation amplifier (typical differential gain A = 1 + lO /Re t)- Abbreviations OA, operational amplifier AZ OA, automatically zeroed OA lA, instrumentation amplifier S, shielding.

Calorimeters are physical objects that can be described in different ways. The steering theory treats a calorimeter as a dynamic object, in which the generated heat effects (input signals) are transformed to the quantity measured directly in the calorimeter, e.g. temperature (output signal). Let us describe the input signals by the functions>>i(0,. ..,... 

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