A new shadow resistance to frequency converter as a read-out circuit for resistive sensors

This paper presents a new resistance to frequency converter. The design is based on a shadow signal generator that produces square and triangular waveforms. The oscillator frequency can be changed using an external circuit (shadow oscillator). This method will make the conversion speed better than the conventional oscillators, and the frequency varies linearly with the resistance variation. The circuit is built using widely available commercial integrated circuits, and powered from a +/- 5-V DC supply. The recommended setup is suitable for instrumentation where the oscillation frequency is directly proportional to the variation in the resistance of the sensor. The functionality of the proposed design was confirmed by experimentation and simulation. The oscillation's frequency can be changed to be nearly 10 times greater than its starting value, according to the results. The circuit diagram of proposed shadow resistance to frequency converter. The design is based on controlling the trip voltage using external circuit. image