What’s your opinion about the E-field sensor? Do you know that E-field sensor is the most suitable component that being used for industrial application. The MC33794-based E-field sensor can be used to detect liquid levels in any plastic containers.
The electrodes are made of aluminium foils and it wrapped all around the container circumference. The whole system is designed around the MC68HC908JK3 microcontroller.
In this project, the MC33794 is being used for applications, where non-contact sensing of objects is desired. Normally, it contains circuitry necessary to generate a low-level electric field and measure the field loading caused by objects moved into the field.
Beside that, the MC33794 is intended for use in detecting objects in an electric field associated with an electrode. The IC will generate a low-frequency sine wave, and the frequency is adjustable by using an external resistor that has been optimized for 125 kHz.
Basically, the sine wave has a very low harmonic content, where it is to avoid the generation of harmonic interference. The internal generator that being included in this E-field sensor will produce a nominal 5.0V peak-to-peak output, where it’s passed through an internal resistor of about 22 kilohms.
By the way, the MC33794 contains support circuits for an MCU. It is to allow the construction of a two-chip E-field system.