exercises

JavaScript Example

JavaScript is a rudimentary object oriented programming language that recent versions of both Netscape Navigator and Internet Explorer respond to without additional software. The grammar and syntax of JavaScript are similar to C/C++. JavaScript permits insertion into HTML documents of, for example, interactive rule-based evaluations of answers provided by users. JavaScript can be used with Netscape Navigator or Internet Explorer running even on machines that are not connected to a network. View the document Source for more details about this example, and about JavaScript.

The following example is based on exercises originally developed for ELECSIM, an interactive electronics software environment described in "Implementation Issues in SIMPLE Learning environments," by William M. Marcy and Marion O. Hagler, which appeared in the Special Issue of the IEEE Transactions on Education 39, CD-ROM folder 35, August, 1996. © IEEE. We thank IEEE Copyrights for permission to use this material.

A problem statement to a user of the exercise below might be the following:

By clicking the appropriate components in the audio amplifier shown below, set the values of Rb1, Rb2, Re, Rc and Vcc to achieve the specified operating point and open circuit signal voltage gain magnitude. (The operators +, -, *, /, as well as ( ), can be used in answers.) Choose Cb and Cc to ensure operation over the entire audio range. Click on the

check

button for an evaluation of your design.

To try the exercise without first carrying out detailed design calculations, overwrite the specified values of Avoc, Vceq and Icq with the following values:

Avoc = 5,

Vceq = 10 V,

Icq = 0.01 A

For these values, the following set of parameters satisfies all of the points checked by the rule base:

Rb1 = 2700 Ohms	Rb2 = 19300 Ohms	Re = 200 Ohms	Rc = 1000 Ohms
Vcc = 22 Volts	Cb = 10 Microfarads	Cc = 20 Microfarads

You might begin with these values and then multiply or divide them by two to see the response of the evaluation. To enter a component value, simply click on the component and follow instructions. The evaluation does not require specific numerical answers to indicate a successful design. Rather, it verifies that certain design rules are satisfied and presents relevant messages if they are not. A circuit simulator, such as PSpice, must be used to verify the performance of the design in detail.

Avoc = Vceq = V, Icq = A

Click the check button for an evaluation of your answers.