I have to design and implement a 4-digit BCD number display system using multiplexed common-anode type seven-segment LEDs.
Using the above,I have to design and implement a 4-digit decimal frequency counter for measuring the frequency of a periodic waveform.
The following info is provided
The given 4-digit BCD number is stored initially in four quad-data latches (IC 7475), each digit in each latch. These digits are to be displayed in four common-anode type seven-segment LEDs (FND 542) via only one BCD-to-seven segment decoder (IC 7447). This requires multiplexing the BCD digits cyclically and enabling only the LED corresponding to the selected digit. Use two dual 4-to-1 multiplexers (IC 74153), each multiplexer for each bit of a BCD digit, for the purpose. For LED selection, use one 2-to-4 decoder (IC 74155) with a pnp transistor as switch between Vcc and the anode of each LED. Implement a mod-4 counter using negative edge-triggered JK flip-flops (IC 74112) to control the 4-to-1 multiplexers and the 2-to-4 decoder.
A frequency counter may be realized by counting the number of cycles in 1 sec. Use an op-amp (IC 741) to convert the given input signal into a TTL-compatible square wave and count the number of cycles in four decade counters (IC 7490). The counting is to be enabled for 1 sec. For this, use a 2-input AND gate (IC 7408) that allows the square wave at one of its input when the other input is HIGH. Generate HIGH pulse of 1 sec duration by driving a JK flip-flop by 1 Hz clock. Obtain 1 Hz clock from a given 100 Hz oscillator by frequency division using decade counters. The contents of the counters are displayed in the above 4-digit BCD number display system at the end of counting. Subsequently, the counters are reset to all zeroes. Generate the negative RESET pulse by using a monostable multivibrator (IC 74121). Measure the frequencies of various periodic waveforms by this frequency counter.
Using the above,I have to design and implement a 4-digit decimal frequency counter for measuring the frequency of a periodic waveform.
The following info is provided
The given 4-digit BCD number is stored initially in four quad-data latches (IC 7475), each digit in each latch. These digits are to be displayed in four common-anode type seven-segment LEDs (FND 542) via only one BCD-to-seven segment decoder (IC 7447). This requires multiplexing the BCD digits cyclically and enabling only the LED corresponding to the selected digit. Use two dual 4-to-1 multiplexers (IC 74153), each multiplexer for each bit of a BCD digit, for the purpose. For LED selection, use one 2-to-4 decoder (IC 74155) with a pnp transistor as switch between Vcc and the anode of each LED. Implement a mod-4 counter using negative edge-triggered JK flip-flops (IC 74112) to control the 4-to-1 multiplexers and the 2-to-4 decoder.
A frequency counter may be realized by counting the number of cycles in 1 sec. Use an op-amp (IC 741) to convert the given input signal into a TTL-compatible square wave and count the number of cycles in four decade counters (IC 7490). The counting is to be enabled for 1 sec. For this, use a 2-input AND gate (IC 7408) that allows the square wave at one of its input when the other input is HIGH. Generate HIGH pulse of 1 sec duration by driving a JK flip-flop by 1 Hz clock. Obtain 1 Hz clock from a given 100 Hz oscillator by frequency division using decade counters. The contents of the counters are displayed in the above 4-digit BCD number display system at the end of counting. Subsequently, the counters are reset to all zeroes. Generate the negative RESET pulse by using a monostable multivibrator (IC 74121). Measure the frequencies of various periodic waveforms by this frequency counter.
