Design & Analysis of Small Signal Bipolar Transistor Model _Common-Emitt...

This model shows the use of a small-signal equivalent transistor model to assess performance of a common-emitter amplifier. The 47K resistor is the bias resistor required to set nominal operating point, and the 470 Ohm resistor is the load resistor. The transistor is represented by a hybrid-parameter equivalent circuit with circuit parameters h_ie (base circuit resistance), h_oe (output admittance), h_fe (forward current gain), and h_re (reverse voltage transfer ratio). Parameters set are typical for a BC107 Group B transistor. The gain is approximately given by -h_fe*470/h_ie =-47. The 1uF decoupling capacitor has been chosen to present negligible impedance at 1KHz compared to the input resistance h_ie, so the output voltage should be 47*10mV = 0.47V peak.

Design & Analysis of Noninverting Amplifier using Op-Amp_ MATLAB Simulink

This model shows a noninverting op-amp circuit. The gain is given by 1+R2/R1, and with the values set to R1=1K Ohm and R2=10K Ohm, the 0.1V peak-to-peak input voltage is amplified to 1.1V peak-to-peak. As the Op-Amp block implements an ideal (i.e. infinite gain) device, this gain is achieved regardless of output load.

Design & Analysis of Inverting Amplifier using Op-Amp_ MATLAB Simulink ...

    This model shows a standard inverting op-amp circuit. The gain is given by -R2/R1, and with the values set to R1=1K Ohm and R2=10K Ohm, the 0.1V peak-to-peak input voltage is amplified to 1V peak-to-peak. As the Op-Amp block implements an ideal (i.e. infinite gain) device, this gain is achieved regardless of output load.

Design & Analysis of Full-Wave Bridge Rectifier_Using MATLAB Simulink

    This example shows an ideal AC transformer plus full-wave bridge rectifier. It converts 120 volts AC to 12 volts DC. The transformer has a turns ratio of 14, stepping the supply down to 8.6 volts rms, i.e. 8.6*sqrt(2) = 12 volts pk-pk. The full-wave bridge rectifier plus capacitor combination then converts this to DC. The resistor represents a typical load.

The model can be used to size the capacitor required for a specified load. For a given size of capacitor, as the load resistance is increased, the ripple in the DC voltage increases. The model can also be used to drive an application circuit in order to assess the effect of the ripple.

Design & Analysis of Finite-Gain Op-Amp_Matlab Based Approach

    This example shows how higher fidelity or more detailed component models can be built from the Foundation library blocks. The Op-Amp block in the Foundation library models the ideal case whereby the gain is infinite, input impedance infinite, and output impedance zero. The Finite Gain Op-Amp block in this example has an open-loop gain of 1e5, input resistance of 100K ohms and output resistance of 10 ohms. As a result, the gain for this amplifier circuit is slightly lower than the gain that can be analytically calculated if the op-amp gain is assumed to be infinite. Plot "Finite Gain Op-Amp Circuit Voltages" shows the input and output voltages for the circuit. If the circuit used an infinite gain op-amp with no input and output resistances defined, the gain would be 1+R2/R1 = 51. Since this model uses an op-amp with finite gain plus input and output resistances, the circuit gain is slightly less.

Dining Philosophers Problem_Matlab Based Approach

    The Dining Philosophers problem is a classical problem, originally formulated by E.W. Dijkstra, to demonstrate classical problems in computer science and the programming of concurrent or parallel processes. Four philosophers are seated at a table, spending their lives in an infinite cycle of thinking and eating. A philosopher must pick up both forks before he can eat. You can think of the philosophers as concurrent processes and the forks as shared resources. The problem is to determine the policy or algorithm so that each philosopher gets to eat and does not starve. For example, one algorithm is for each philosopher to pick up first the fork to his right, then the fork to his left, before he eats. That this will eventually lead to a deadlock situation where all of the philosophers are holding one fork, waiting for each other to put down their forks.

Design & Analysis of Differentiator using OP Amp_Matlab Simulink

    This model shows a differentiator, such as might be used as part of a PID controller. It also illustrates how numerical simulation issues can arise in some idealized circuits. The model runs with the capacitor series parasitic resistance set to its default value of 1e-6 Ohms.

Design & Analysis of Band-Limited Op-Amp_Using Matlab Simulink

    This example shows how higher fidelity or more detailed component models can be built from the Foundation library blocks. The model implements a band-limited op-amp. It includes a first-order dynamic from inputs to outputs, and gives much faster simulation than if using a device-level equivalent circuit, which would normally include multiple transistors. This model also includes the effects of input and output impedance (Rin and Rout in the circuit), but does not include nonlinear effects such as slew-rate limiting.