Transducer Circuit Description
In order to integrate our EMG Circuit and our micro-controller we needed to construct a transducer that would only allow a maximum of 5 volts at the input of the controller.
The transducer circuit is used to control the level of voltage that is inputted into the micro-controller. The maximum rating that the controller can handle is 5 volts DC. Therefore the transducer makes sure that the pulses are never larger than 5 volts. The first stage in the circuit is an amplifier controlled by the feedback 10K pot. This pot adjusts the gain to the desired level, in our case just below 5 volts, about 4.8 V DC. The second pot, 10K also, controls the balance of the voltage, it is to be adjusted to 0 volts. The second stage of the transducer is a unity gain amplifier. It’s only purpose is to invert the previous waveform. This is needed because the first stage inverts the signal negatively.