Q3: I can't simulate a Logic Component like Operational Amplifier or Multiplier (AD632). In fact, when I go to Mixed Mode Simulation, EDWin says that it's a not simulated component. But in Database filter, there is no problem. Do you have an answer?

To know whether a component can be simulated or not, open Library Browser. From View/ Options menu, check the option ‘Simulation Function’ and search for the component. If the component is having a simulation function, the information will be listed in the table corresponding to ‘Simulation Function’ below after the search.
AD632 does not have simulation functions assigned to it. The only OPAMP that has simulation primitives assigned to it in mixed mode is OPAMPA in the library file a_linop.SYMBOL. The same simulation primitives may be assigned to any other opamp that has matching number of pins

Q4: How can LED’s and 7 segment displays be simulated?

You can assign the simulation function for Diode to LED symbol and do the simulation in Mixed Mode Simulator. In EDSpice, there are Model parameters for LED's in LED.sparam.

Q5: What is written in clock generator string to output 15 KHz clock pulses? How can 15KHz clock pulses be detected?

(H20,L47)[?s] as generator string, will produce a Pulse train, starting with a Mark of 20 micro seconds and a Space of 47 micro seconds, the time period is 67 micro seconds (for 15Khz, it is 66.67 micro seconds, To increase the precision, choose time in nano seconds, ns instead of ?s, and give appropriate values). For a pulse Train of 100, the generator string is 100(H20,L47)[?s]. Add ‘Logic state TP’ right at the pin where you assigned the Generator String and when Transient analysis is done, you get the Pulse Waveform in the diagram.

Q6: Can custom Mixed-Mode simulator models be created?

Yes, custom mixed mode simulator models may be created provided simulation primitives are available. If the symbol works like any other symbol for which a simulation primitive is already available, you can assign the same primitive to it. If not, you will have to write the DLL (simulation primitives) for simulating it and then assign it. The DLL primitive source code is written in C programming language. The creation or updation of the primitives requires some knowledge and practice with the C programming language. You may find the necessary documents for this on the EDWin XP/2000 CD under the directory named Simmodel.kit.

Q7: I'm trying to add a new component to Edwin and have some questions. When creating a new Part, you can assign a simulation function to it. But I can't find the way of specifying it's electrical characteristics and save them within the Part. Where can I enter these parameters?

You can assign simulation function to a symbol. After assigning the simulation function to the symbol, load it into the project. Invoke Mixed mode Simulator and select the tool "Set parameter" (option tool of the functional tool “Set parameter/ Models”) in the tool bar and click on the symbol. You will get a window where you can edit/ enter the values. Save the edited parameters into a separate library.

Q8: Making changes to schematic circuit and preprocessing does not appear to re-configure the 'nets' correctly i.e., have to re-edit the nets?

Always see that you edit the net and not the wire connection. For example if you delete a wire in schematic, the wire gets deleted but the net remains. So after preprocessing, the net still remains. Before making any changes to nets you should confirm that you deleted the net or a part of it. Deleting wire connection will not delete net connection. It only deletes physical representation.

Q9: I am trying to use the mixed mode simulator to calculate power on a resistor. In the waveform viewer, I click ADD to add a trace, then type in a formula PWR (R9) that generates an error when I try to APPLY it. The plot shows zero power. How do you get a plot of the power in a resistor?

To calculate the power in a resistor, you should place two markers for voltage and current at the resistor node and from the equation generator, explicitly enter the variables in the format Voltage* Current and then calculate the power.

For e.g.: enter in the expression list box:

V1 (GEN) * I1 (Unpck16: PIN1)
to calculate the power at a resistor. And in the Units list box enter the unit to which the diagram should be displayed, i.e. W.

The PWR function is unused for calculate the X raised to the power of Y.
For e.g.: PWR (3,2) which will give you 9 as output.