As described in the license agreement, you are permitted to run one copy of the orcad software on one computer at a time. Question regarding voltagecontrolled resistors in pspice. The currentcontrolled voltage source actually implements two individual devices, as can be seen from the netlist template. In the subcircuit, the time derivative, dvtdt, is measured by applying a copy of the voltage across gout to a known capacitance, cref, and monitoring its current. For example, if we desire to know the voltage across a capacitor whose leads connect between nodes 4 and 7, we might make out. To insert and configure a switch in ltspice insert the symbol for the voltagecontrolled switch in your schematic press f2 and type sw in the search field of the symbo. The following will be a brief introduction to digital analysis using pspice, you should consult the online pspice manual if you are unsure about any of the following properties. Hi i am designing a feedback circuit for the resonant converter and in the feedback loop i planned to use a voltage controlled oscillator vco before going to the hardware i want to simulate that in pspice, i am new to the pspice and could not figure out whether vco is available or not, can any one please help me to find the vco in pspice, i am using student 9. Mar 01, 2012 here is a zip file for ltspice that has the subcircuits and the. Hello everyone, just a video explaining how to reproduce an example simulation from standard pspice learning modules in the orcad trial and the orcad lite 17. The capacitor is chosen to be large to provide an early roll off f 12. I am designing a feedback circuit for the resonant converter and in the feedback loop i planned to use a voltage controlled oscillator vco before going to the hardware i want to simulate that in pspice, i am new to the pspice and could not figure out whether vco is available or not, can any one please help me to find the vco in pspice, i am.
Recommended citation mupparty, durga bhavani, capacitor switching transient modeling and analysis on an electrical utility distribution system using simulink software 2011. In pspice, this can be done using the etable component in the. This is the undocumented off state resistance of the cl voltage controlled switch. Hsrc currentcontrolled voltage source model online. Now i am doing a ac simulation and i have a need to set the voltage across a capacitor to zero. Compare the pspice result with the mathcad results 4. Referring to the simulation result in pspice, i also wondered why is there no current flow through the 2 ohm resistor expected 0. Vpwl uses linear interpolation between the specified points, the t8 value will remain till the end of the simulation. I want to model a capacitor using the equation q cv. Lets assume there is a 100nf capacitor between nodes 6 and 7, and we want to set an initial condition of 5v across the capacitor. This is equivalent to the standard pspice capacitor model, whose linear and quadratic coefficients, vc1. Pwl method is a subset in vccsvoltage controlled current source dependent source of spice simulator and we can define two dimensional cv coordinates for cv curves. Pspice can simulate digital circuits and probe can output a timing diagram showing the relationship between all the signals propagating in the circuit. One classic application of voltage controlled switches is simulating opencircuit and shortcircuit conditions.
Pspice, a factor of 106 is indicated by meg or meg. There are three ways to set a voltage across a capacitor. Setting initial conditions across a capacitor spectrum software. The display window will open and a graph of the capacitor voltage. For instance, suppose we wanted to make the voltage source above model.
Jan 20, 2018 hello everyone, just a video explaining how to reproduce an example simulation from standard pspice learning modules in the orcad trial and the orcad lite 17. Voltage controlled oscillator in pspice all about circuits. Ltspice includes a large number of excellent fet models, but sometimes you need to simulate a simple switch that opens and closes at specific times or under certain conditions. The smooth transition follows a low order polynomial fit to the logarithm of the switchs conduction.
It is still tr, even if the v1 software on one computer at a time. Rc circuit with voltage probe running and displaying the results of the simulation run the simulation. Firstly, i considered i o as a 1a dc current source in pspice. Time varying voltage controlled capacitor ltspice or pspice.
To make a vco, the oscillator needs to be tuned by a voltage. Examples consider the voltage controlled switch in the above image, with the following characteristics. The nonlinear capacitor is modeled by a subcircuit in which the capacitor is replaced by a controlled current source, gout, whose current is defined by 2b. But i have to change the capacitnace and keep the charge constant to simulate an electrostatic energy harvester. Jul 12, 2018 voltage controlled oscillator practical application as mentioned earlier vco can be simply construct using rc or lc pair, but in real world application no one really does that.
In many cases, we need to use switches that open and close at certain times or under certain conditions of voltage or current. A capacitor model with c01, c12,c20 is used in the circuit on leftside in figure 7, making capacitance linearly proportional and twice the value of input voltage. All you need is a controlling voltage to multiply the resistor value. Click on waybackmachine to see how our website looked. Use pspice and probe to obtain the transient response of the capacitor voltage and capacitor current separately on one page. Spice quirks using the spice circuit simulation program.
There is some dedicated ic which has the ability to generate oscillations based on the input voltage. Pspice schematic with current controlled voltage source note that the right side of the. Connecting currentcontrolled voltage source in pspice. In the transient analysis use a final value of 6 second. Click on project raptor to start calculating your power supply parameters. The tune voltage for the vco can then be applied to the varactors. How to implement dependent sources in orcad pspice. It does not, for example, show the temperature and frequency dependence of the various elements. Another quirk of pspice is the designation for 106. Figure 1 above shows an example of a circuit with a current controlled voltage source. Previously with pspice the initial condition setting applies. Resistors, capacitor, and inductors are part of the analog library. In circuit 1 i have a certain voltage, let us call it v1. Resistor r b and capacitor c b form a b1 2015 oxford university press reprinting or distribution, electronically or otherwise, without the express written consent of oxford university press is prohibited.
Use pspice and ac analysis for a single point 60 hz to obtain the node voltages v1 and v2, and current in r3. Several libraries come available with pspice, and these have all of the components we will use in. A simple addition to the above resistor model gives you a voltage controlled resistor. The above method will only set the absolute voltage on the node. Display measurement of dc differential voltage in pspice. Voltage controlled switch not working circuitlab support. Using p spice a transient analysis of the voltage across the capacitor was run from time t0 to t1s. In circuit 2 i have a resistor r1, with a value that i want to be dependent on v1. If you doubleclick the e1 dependent voltage source in pspice, you may find the gain property. The four types of dependent sources are listed below in table 1 along with their abbreviation, pspice name and library. For more information on voltage controlled switch please refer to ltspice help file f1. This video shows how to implement dependent sources in pspice software. It is likely that the old url for this pspice tutorial will disappear on august 31, 2015. Modeling voltagecontrolled resistors and capacitors in pspice.
Then, i have tried to connect the 4terminal currentcontrolled voltage source in pspice but i am not sure whether it is correct. A nonlinear capacitor model for use in the pspice environment. Your circuit should now appear as shown in figure 2. The first is a 0v voltage source, which acts as an ammeter, to measure the current input and then the actual currentcontrolled voltage source that references it. Switching power supply design, pspice simulation, tutorials, technical articles, design tips. Dependent sources dependent source abbreviation pspice name library voltage controlled. I am quite new to pspice, and i am using capture to design my circuit. To add it, click the add library icon, circled in green above. Pspice will complain and refuse to run the simulation. If we needed, we could use the plot cursors to measure various points on the output voltage curve to determine the ripple voltage. To explain what i am trying to do, i have two circuits that i want to connect via a voltage in the following manner.
Pspice tutorial dc transient simulation charging a capacitor. Pspice has many excellent models of transistors, thyristors and other devices that react to changes in a base circuit or a gate input. Time varying voltage controlled capacitor ltspice or. Simulation of circuits with inductors and capacitors. I can access the voltage across this charge source. As discussed in class there are four types of dependent sources, two are voltage sources and two are current sources. Vsw voltage controlled switch model online documentation. The simulationready voltage controlled switch component vsw can be found in the simulation special function integrated library \library\simulation\simulation special function. For example if you set a capacitors initial voltage to 10v, pspice will place 10 volts across the capacitor with its 1 end positive with respect to its 2 end. Note that if a cl voltmeter were to be connected in place of r1 then there would be a clear onoff state difference because the cl voltmeter has a user definable finite resistance with a default value of 1g. It will be noticed that the control line from the phase detector is isolated from the varactor diodes. The default value for the step ceiling was used the result is shown on the next page. Open a new pspice project and enter this schematic. Download pspice for free and get all the cadence pspice models.
As far i know with ltspice it is just possible to vary the charge. The value of the nonlinear capacitor model in this example has a second order polynomial dependence on its voltage. Pspice ad digital simulation condition messages 61. Voltage level, and place the probe that appears at the top of the capacitor. Just like the dc offest on the function generators in lab. Capacitor capacitance attribute the second way is in the capacitance attribute of a capacitor. Pspice tutorials pspice tutorials contents 1st tutorial. In figure 7, the two circuit simulate the following two voltage controlled capacitors. Heres why it appears not to be working at the start of the sim, c1 is already charged up to approximately 1v because the switch has a finite but large off resistance and the simulator assumes that the switch has been open circui and that 1v has been applied for an infinite time prior to the start of the sim at t0. If you have placed the device in your circuit upside. Transforming the voltage source to the current source and writing the nodevoltage equation results in. This popular version of spice, available from orcad now cadence runs under the pc platforms. Examples consider the voltage controlled switch in the. Dec 28, 2014 this video shows how to implement dependent sources in pspice software.
Add a 47f capacitor in parallel with the load resistor to make a peak recti. Here is a zip file for ltspice that has the subcircuits and the. I am trying to simulate the circuit of novel high stepup dcdc converter with coupledinductor and voltagedoubler circuits in pspice with specified rating 24v input, 200v output, 250w power. Above is an electrical model of a capacitor, the most common one anyhow. This can be achieved by making the variable capacitor from varactor diodes.
927 1530 557 1070 279 344 937 1121 1213 483 1074 1171 1306 1498 45 145 560 1479 1620 1507 1583 950 1439 266 847 563 1381 1067 1276 162 1155 797 754 1140 1232 167 128 1102