Bessel-Thompson filter

A Bessel-Thompson filter was designed to have a delay close to 500 /us. The design procedure followed gave exact values for all of the capacitors and resistors. These values are rounded to the nearest value of capacitor available. The SPICE packages are used to determine what the implemented delay will be. Measured values of all the components used in the hardware are used. The schematic and the breadboard results are shown as Figs. 3.23 and 3.24, respectively. 

A quick modification to the Bessel-Thompson filter leaves us with a high pass filter. This filter does not have the built-in delay like the low pass version, but it does provide an interesting response. The schematic and the breadboard results are shown in Fig. 3.36 and Fig. 3.37, respectively. The measurements that will be made for comparison purposes are the step response height and the time until the second cross of the zero axis. 

Bessel-Thompson Delay Low Pass Filter with Pulse Shaper... 

A simple pulse-shaping modification can be added to the Bessel-Thompson delay filter by using an additional operational amplifier. Resistors are used to divide down the supply voltage to half the output voltage of the delay filter, and its response is then compared with the delay filter s response, which results in a time-delayed square wave. The schematic of this circuit is shown in Fig. 3.31. This simulation also allows us to compare the operational amplifier models that came with each software package. The response of this circuit is driven from rail to rail, providing the saturation voltages of the models. Also, the slew rate of the output should be consistent with the measured and... 

Figure 3.31 Bessel-Thompson delay filter with shape reformation.

Inverted Bessel-Thompson Delay High Pass Filter... 

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