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Duty-Cycle Measurer

Not rated 15,055

#duty cycle #A/D converter #pulse train #Intersil 7101 #measurement #percentage display #digital display #signal analysis
Duty-Cycle Measurer
Duty-Cycle Measurer

Description: An Intersil 7101 31/2-digit A/D converter is utilized to display the duty cycle of a pulse train as a percentage. The frequency range of this circuit is from 100 Hz to 250 kHz. CMOS gates are employed to convert the pulse train to a constant amplitude. This amplitude is subsequently compared to a reference voltage of 1 V, which is derived from resistors R3 and R4. PI is included for calibration purposes.

The circuit operates by first capturing the incoming pulse train, which can vary in frequency between 100 Hz and 250 kHz. The Intersil 7101 A/D converter is designed to process this signal and convert it into a digital representation that reflects the duty cycle as a percentage. The duty cycle is defined as the ratio of the time the signal is high to the total period of the signal.

To ensure accurate conversion, the CMOS gates function to stabilize the pulse train by converting it into a constant amplitude signal. This step is crucial as it allows for a consistent input to the A/D converter. The constant amplitude signal is then compared against a reference voltage of 1 V, which is established through a voltage divider configuration using resistors R3 and R4. This reference voltage serves as a baseline for the A/D conversion process.

Calibration is an essential aspect of this circuit, and it is facilitated by the inclusion of a proportional integral (PI) controller. The PI controller adjusts the output based on the difference between the measured duty cycle and the desired duty cycle, thereby enhancing the accuracy of the displayed results.

Overall, this circuit design effectively measures and displays the duty cycle of a pulse train over a wide frequency range, providing a reliable tool for applications requiring precise duty cycle measurements. An Intersil 7101 31/2-digit A/D converter is used to display the duty cycle of a pulse train as a percentage. The frequ ency range of this circuit is 100 Hz to 250 kHz. The CMOS gates convert the pulse train to constant amplitude. This amplitude is then compared to a reference of 1 V, derived from R3 and R4. PI is for calibration.

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