* Activity 1:
Using Multisim, construct a simple 0-5V DC digital voltmeter using the ADC (rather than the ADC0804) and the 74185 to convert the binary output into BCD, which will be displayed on two 7-segment displays. The 74185 will be used to convert a 6-bit binary number to a 2-digit BCD number. Note that the 2 least significant A/D output bits are left unconnected (using only 6 bits of resolution). Calibrate the digital voltmeter by applying 5V to the analog in (measured with a DVM) and adjusting the potentiometer until the 7 segment display reads 5.0 (the decimal point is assumed to be in the middle). Test the accuracy of the digital voltmeter with several different values for analog in.
* Activity 2:
Using Multisim, use the A/D converter to digitize a sine-wave input signal and then reconvert the representative digital signal into an analog signal with the DAC (in Multisim this is called a VDAC). Connect the input of the D/A converter to the output of the A/D converter. Make sure the MSB out is connected to the MSB in. Adjust the input sine wave to 2.5Vp-p with a DC offset of 1.25 volts (i.e., the sine wave goes from 0 to 2.5V). Adjust the Vref/2 voltage using the potentiometer so that the analog input span on the ADC is 0 to 2.5V. Use an oscilloscope to compare the analog input and output waveforms. Set the analog input signal frequency to 200Hz and observe the resultant analog output signal. Increase the input signal frequency and note the effect on the resultant output signal.
Please see attached Multisim files and the document for the explanation of the ...
This posting contains the solution to the given problems.
Design a Multisim circuit for a fuel-level sending unit.
The gas tank on your car has a fuel-level sending unit that works like a potentiometer. A float moves up and down while the gasoline level, changing the variable resistor setting and producing a voltage proportional to the gas level. A full tank produces 12V, and an empty tank produces 0V. Design a Multisim circuit using an LM339 that turns on "Fuel Level" indicator lamp when the voltage level from the sending unit gets below 0.5V.View Full Posting Details