Grid resistors

Figure 5.3(c) Al-Cr alloy steel punched grid resistor in multitier arrangement (Courtesy BCH)... 

Fig. 13.6 (a) CNT array with lateral ballast resistors to the square grid, (b) honeycomb patterned mesh structure of CNT emitters (courtesy W. I. Milne). 

Figure 7.12 A network of resistors can be used to perform the last step of the algorithm, i.e. the integration. Each point of the grid is connected to its immediate neighbors by a resistor of resistance R. It is also connected to its diagonal neighbors by a resistor of resistance 4R.

Let us consider the one-dimensional case again. Figure 10.14 shows a linear network of resistors. If we carry out the same derivation as mentioned earlier but now for a onedimensional resistive grid, we arrive at the following equation (Jahne 2002) ... 

Resistance heating usually involves the highest electricity costs, and may require circulating fans to assure the temperature uniformity achievable by the flow motion of the products of combustion (poc) in a fuel-fired furnace. Silicon control rectifiers have made input modulation more economical with resistance heating. Various materials are used for electric furnace resistors. Most are of a nickel-chromium alloy, in the form of rolled strip or wire, or of cast zig-zag grids (mostly for convection). Other... 

The final step required to demonstrate the validity of the polymer grid triode implementation of local contrast enhancement is to show that it computes the center-surround difference in Eq. 2. The equivalent circuit of the PGT demonstrated previously (3, 4) is that of two coupled diodes connected back-to-back, like that of a bipolar transistor (5). This is achieved by using semiconducting polymer in layers (2), (3 and (4). For the prototype array sketched in Figure 2c, layer (2) was fabricated with a material with sufficient conductivity to make an ohmic contact to the grid so that the equivalent circuit is simplified to a diode in series with a resistor. In the initial experiments, polyvinylcarbazole (PVK) was used for this resistor layer (2). In forward bias,... 

As shown in Fig. 5.30, the addition of a 12.5-k 2 resistor from screen to ground provides a path for screen grid emission (20 mA for the circuit shown). In the circuit of Fig. 5.31, plate current flows through the screen power supply, swamping the screen supply. The screen power supply must, obviously, carry the normal screen and plate currents. This scheme is used extensively in circuits where the screen is operated at DC ground potential. The plate-to-cathode voltage is then the sum of the Ei and Ecj power supplies. 

Place a small cod and resistor combination in the plate lead between the plate of the tube and the tank circuit, as shown in Fig. 5.63(a). The resistor-cod combination is usually made up of a noninductive resistor of about 25-100 S2, shunted by three or four turns approximately 1/2-in diameter and frequently wound around the resistor. In some cases it maybe necessary to use such a suppressor in both the plate and grid leads. The resistor-cod combination operates on the principle that resistor loads the VHF circuit but is shunted by the cod for the lower fundamental frequency. In the process of adjusting the resistor-cod combination, it is often found that the resistor runs hot. This heat is usually caused by the dissipation of fundamental power in the resistor, and is an indication of too many turns in the suppressor coil. Just enough turns should be used to suppress the parasitic and no more. Once the parasitic has been suppressed there wdl be no parasitic voltage or current present. Therefore, there is no parasitic power to be dissipated. 

Circuit Failure Type Fixed Grid Bias Resistor Grid Bias Fixed Grid Bias Resistor Grid Bias... 

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