Signal Generator Circuit Carrying Information as Embedded Features from Multi-Transducer Signals

A novel circuit for generating a signal embedded with features about data from three sensors is presented. This suggested circuit is making use of a resistance-to-time converter employing a bridge amplifier, an integrator and a comparator. The second resistive sensor (Rz) is transformed into duty cycle. Another bridge with varying resistor, (Ry) in the feedback of an OP AMP is added in series to change the amplitude of the resulting signal in a proportional relationship while keeping the same frequency and duty cycle representing proportional changes in resistors Rx and Rz already mentioned. The resultant output signal carries three types of information embedded as variations of its frequency, duty cycle and amplitude.

Authors:

• Sheroz Khan
• Mustafa Zeki
• Shihab Abdel Hameed
• AHM Zahirul Alam
• Aisha Hassan Abdalla
• A. F. Salami
• W. A. Lawal

Keywords:

• Integrator
• Comparator
• Bridge Circuit
• Resistanceto-Time Converter
• Conditioning Circuit.

References:

[1] C. D. Johnson and H. Al. Richeh, "Highly accurate resistance
deviation to frequency converter with programmable sensitivity and
resolution," IEEE Trans. Instrum. Meas., vol. IM-35, pp. 178-181,
1986.
[2] K. Mochizuki and K.Watanabe, "A high-resolution, linear resistanceto
frequency converter," IEEE Trans. Instrum. Meas., vol. 45, pp.
761-764, 1996.
[3] S. Kaliyugavaradan "A Linear Resistance-To-Time Converter with
High Resolution," IEEE Transaction on Instrumentation and
Measurement, Vol. 49, NO. 1, February 2000.
[4] Vittorio Ferrari, Carla Ghidini, Daniele Marioli, and Andrea Taroni.
"Oscillator-Based Signal Conditioning with Improved Linearity for
Resistive Sensors," IEEE Transactions on Instrumentation and
measurement, Vol. 47, NO. 1, February 1998.
[5] Walt Kester, Editor, Bridge circuit; 1993
[6] Ferran Reverter, Manel Gasulla and Ramon Pall`as-Areny. "Analysis
of interference effects on period-to-digital conversions"
Instrumentation, Sensors and Interfaces Group, Castelldefels School
of Technology (EPSC), Technical University of Catalonia (UPC),
Avda del Canal Ol'─▒mpic s/n, C4, 08860 Castelldefels (Barcelona),
Spain