This section covers the functions of the General Electronic Menu. Selecting the “Elec Calc” item from the menu accesses functions.
Selecting this tab allows the user to perform various Ohms Law calculations. The basic V=IR and the variations of it as shown on the screen. In addition it also calculates wattage and HorsePower Hp. Any two parameters (V,I,R & W) can be input and the remainders are calculated. The Hp calculation uses the Watts and Efficiency to calculate. The default efficiency is 90%. Figure below shows a voltage of 120V and current of 6.5Amps and the Resistance and Wattage and Hp are all calculated. Press “Calculate” to perform, “Clear” to clear and start over and “Close” to quit the screen.
Figure 15 – Ohms Law
Selecting this tab allows the user to make resonance calculations using any three of the four possible inputs ohms, inductance, capacitance and frequency. Figure 11 shows a resistance, inductance and capacitance input to calculate the resonant frequency, Q and series / parallel impedances shown in figure.
Figure 16 – Resonance
Selecting this tab allows the user to make general inductance calculations of series and parallel inductance. The user can also select to determine the reactance impedance of an inductor value at a specific frequency.
Figure 17 – Inductance
Selecting this tab allows the user to make general capacitance calculations of series and parallel capacitance. The user can also select to determine the reactance impedance of a capacitor value at a specific frequency.
Figure 18 – Capacitance
Selecting this tab allows the user to make general resistance calculations of series and parallel resistance and also Voltage Divider applications.
Enter the R1 and R2 values in the Parallel and Series Resistance section and press the right Calculate to compute the Parallel and Series Resistances.
For the Voltage Divider application enter any three of the four input and press the Left Calculate and it will compute the missing member of the set. In addition is will also calculate the total current thru the voltage divider. In the case shown in figure below, the input voltage is 28V and the voltage output desired is 5V and the upper resistor, which for the most part will determine the major resistance and determining the approximate current flow is 3K Ohms. This should give about 1mA of current. Indeed the calculated R2 value for the lower resistor is 652 Ohms with 1.369mA total unloaded divider current flow.
Figure 19 – Resistance Parallel and Series and Voltage Divider
Selecting this tab allows the user to make general US and Metric distance calculations and also temperature conversions. User inputs any one value for either calculation and all the others for that selection will be calculated.
Figure 20 – Temperature/Distance Conversion
Selecting this tab allows the user to make inductor value estimates for Straight Wire, Straight Wire Offset from Ground and coil inductance. Input the wire radius in centimeters (cm) and the wire length in cm, then press the calculate Wire Inductance. If the Straight Wire from Ground calculation is desired, then add the Input Distance from Ground in cm and press the next Calculate Wire Inductance button. If the Coil Inductance is desired then input the Radius (cm), length of the coil and either the turns or the inductance. Whichever of the last two is input the other will be calculated when the Calculate Coil Inductance is pressed.
Figure 21 – Inductors Length, Radius, Inductance Input
Selecting this tab allows the user to Calculate Parallel Plate Capacitance, or Coaxial Cylinder capacitance. Input the Er – Dielectric Constant and either the Area and Distance (separation) or the Inner Diameter and Outer Diameter to calculate the respective Parallel Plate or Coaxial Cylinder Capacitance.
Figure 22 – Capacitors
This selection allows the user to get the resistor colors or identifiers for inputs to values. The Resistor Color Bands are for 2, 5, 10 and 20% tolerance resistors. The numeric identifier is used for the 1% tolerance resistors. The pull down item “text box” inputs is fixed to the range of values available. The actual resistance value is shown in the Resistance Text Box output when calculated. Included in the calculations are the upper and lower bounds of the resistor value with the applied tolerance applied.
Figure 23 – Resistor Color
Used for general Resistivity and other measurements.
This screen helps the operator perform Resistivity calculations. Enter the Area in Sq cm, Length in cm, Temperature, and Temp Coefficient. If the user selects the check box and the type of material predefined, then the Resistivity and Temp Coef will be filled in automatically for you. Then press “Calculate” to get the Resistance. Press “Clear” to clear the coefficients and begin over. Press “Close” to quit the screen and go back to main menu. The material list and coefficients are in the iNI file and can be added to or modified. I have selected most used standard materials for initial inputs.
Figure 24 - Resistivity
This screen helps the operator perform Skin Depth calculations. Enter the Conductivity and frequency of operation in Hz. If the user selects the check box and the type of material predefined, then the Conductivity will be filled in automatically for you. Then press “Calculate” to get the Skin Depth in cm. Press “Clear” to clear the coefficients and begin over. Press the “Close” button to quit the screen and go back to main menu. The material list and coefficients are in the INI file and can be added to or modified. I have selected most used standard materials for initial inputs.
Figure 25 – Skin Depth
This screen helps the operator perform Y to/from Delta calculations. Enter the three Delta or the three Wye resistances and press “Calculate” to get the conversion resistance equivalents. Press “Clear” to clear the resistances and begin over. Press the “Close” button to quit the screen and go back to main menu.
Figure 26 – Y-Delta conversions
This screen will perform he calculation for Wire Resistances. Use the pull down combo boxes to select the wire type or Awg and also the material type. Check the Check box to use the combo box selection inputs for Area, Resistivity and Temp Coef. Otherwise enter your own values. Also enter the Length and Temperature. Temperature will default to 25 deg C. Press and “Calculate” to get the wire resistance, press “Clear” to clear the fields and begin over. Press the “Close” button to quit the screen and go back to main menu.
Figure 27 – Wire Resistance
This screen can compute the missing resistor value for a “Balanced Bridge” condition (V2=0). By entering three of the four resistor values and pressing “Calculate” it will compute the missing resistor value. “Clear” to clear all the values and “Close” to close the window and return to the main menu.
Figure 28 – Wheatstone Bridge Resistances
Selecting this tab will allow the user to make calculations for PI and Tee attenuators. The inputs are Loss in dB, Zin and Zout (input and output impedance). The user then selects “Calculate Pi” or “Calculate Tee” for the respective calculation. After this is performed the user can select to convert Tee to PI or PI to Tee if desired by pressing the respective button for the operation. The user can also select Clear all or Clear Att(enuation) to rerun, without losing all the inputs.
Figure 29 – PI<>Tee Attenuation
Selecting this option the user can enter an Input Impedance ZIn and an Output Impedance Zout and calculate the parallel and series resistor value that will make a minimum loss attenuator for a match between line of different impedances (i.e. 50 to 75 Ohms or 75 to 300 Ohms-Cable to TV) It also calculates the loss factor in decibels (dB). Note: ZIn must be greater than ZOut! The two resistor values are the series and parallel resistance
Figure 30 – Minimum Loss Attenuator