Home Site Map What's New Company Info Contact Us
Frequent Questions

Up ]


This page answers frequently asked questions about Computer Aided Resonator Design (CARD).

bulletEquipment requirements


bulletIs CARD available in any language other than English? No. All menus and on-line help are in English only.


bulletCan CARD analyze resonators that vibrate in flexure (bending), radial, or torsional modes? Generally, CARD cannot analyze flexural, radial, or torsional resonators that have an arbitrary shape; CARD can only analyze resonators that vibrate longitudinally (parallel to the axis of the resonator). However, CARD has an Equations section that allows some calculations for simple flexural, radial, and torsional resonators (beams, plates, disks, rings). These simple resonators are those that can be described by classic differential equations.
bulletCan CARD analyze transducers (converters)? Yes. CARD can determine the longitudinal resonant frequency and the relative stresses, amplitudes, and losses (with the same accuracy and limitations as with any other resonator analysis). CARD works best for relatively slender transducers, such as handheld transducers used in medical applications. CARD is not well suited for analyzing "fat" transducers (e.g., those used for cleaning tanks).
Note: CARD cannot currently determine the actual output amplitude for a specified electrical input, since CARD does not have the piezoelectric transformations. This capability may be included in a future release if there is sufficient demand.
bulletCan CARD determine higher harmonic resonances? Yes. This works well for relatively slender resonators. As the frequency of the harmonic resonance increases (i.e., the resonator becomes fatter in relation to the half wavelength), the accuracy decreases.

Equipment requirements

bulletWill CARD run on an Apple computer? No. CARD will only run on an IBM-compatible computer. The operating system must be either Windows or DOS. For other equipment requirements, click here.


bulletI receive the following error message when attempting to start CARD: "The copy protection key must be plugged into the printer port" (or similar). CARD has failed to recognize the copy protection key. Try each of the following, in turn:
a. Make sure the copy protection key is plugged into the parallel printer port, not the serial port.
b. If a printer is attached to the copy protection key, make sure it is turned on and ready to print. (Try printing a page from another application, such as a word processor.)
c. Turn the printer off and disconnect the printer cable from the copy protection key. If this corrects the problem, then the printer is probably interfering with the copy protection key. This is especially likely if the printer is a Hewlett-Packard with bi-directional capabilities. To resolve this problem:
   i. Install HP's newest drivers.
   ii. If the newest drivers don't solve the problem, then install a second printer port that is dedicated solely to the copy protection key. This is relatively easy and should cost about $20.
   iii. Use a different printer.
d. Turn the printer off and disconnect the printer cable from the copy protection key. Run Keshow.exe. This will show the status of the copy protection key.
bulletCan CARD be used on multiple computers? Yes. However, CARD can only be used on the computer that has the copy protection key attached. If you want to use CARD on another computer, then you must transfer the copy protection key to that computer.
bulletWill CARD operate on a networked computer? Yes. However, the user must run CARD from the computer where CARD has been installed and where the copy protection key is attached. Also, although CARD may print satisfactorily to a networked printer, this will depend on the particular network and is, therefore, not guaranteed. For additional information, see CARD's online help at <Alt+H>\Setup and starting procedures\Printer setup\Printing on a network\.
bulletIs CARD Y2K compliant? Yes. CARD does not use any function that manipulates or depends on the date.
bulletHow should CARD be uninstalled? If you find that CARD does not meet your requirements, then you can simply delete the directory (folder) in which CARD has been installed. (Note: since CARD is not a Windows program, it would not have made any changes to the Windows' Registry.)


bulletAfter I machine a resonator, the tuned length (or frequency or gain) is not the same as predicted by CARD. Card gives approximate results based on a one-dimensional analysis. These results are intended to assist with design, not to give absolutely correct values. (See method of analysis. Also see chapter 6 "Impedance Matching" in the CARD manual.) Where CARD's internal accuracy is not sufficient, a calibration mode has been provided.
bulletHow can I print CARD's graphics? See CARD's online help at <Alt+H>\Setup and starting procedures\Printer setup\.  Then select either "Printing graphics under DOS" or "Printing graphics under Microsoft Windows".


bulletHow do I replace the battery in the copy protection key? The copy protection key has a button that contains two components:
a. the copy protection integrated circuit.
b. a ten-year battery.
It is unlikely that the battery will ever need to be replaced. If required, the button can only be replaced by Krell Engineering.
bulletWhat should I do if the copy protection key becomes damaged? Contact Krell Engineering. If required, the key will be repaired or exchanged for a fee.
bulletWhat should I do if the copy protection key is lost? The copy protection key is an indicator of authorized use. Therefore, if you lose the copy protection key, you must purchase an entire CARD.


Top | Home | Site Map | What's New | Company Information | Contact Us

Krell Engineering
212 E. Medwick Garth    Baltimore, MD  21228    USA

e-mail: info@krell-engineering.com