Powder Level Sensors Piezoelectric type LTS(3-terminal type self-oscillation formula) series TSP(2-terminal type separate excitation oscillation formula) series Issue date: • All specifications are subject to change without notice. • Conformity to RoHS Directive: This means that, in conformity with EU Directive 2002/95/EC, lead, cadmium, mercury, hexavalent chromium, and specific bromine-based flame retardants, PBB and PBDE, have not been used, except for exempted applications.

Powder Level Sensors LTS, TSP Series TDK’s piezo-type level sensor, which uses a sensor element consisting of a piezoelectric ceramic, was developed originally by TDK. The sensor detects the presence of powder when the sensor element, which a built-in oscillating circuit causes to vibrate, comes into contact with powder and the vibrational conditions are altered. The TSP series, which employs an external source of oscillation based on a custom chip, offers even better operational stability. FEATURES • This is a unique sensor that employs a piezoelectric ceramic sensor element. • The exterior...

3-TERMINAL TYPE SELF-OSCILLATION FORMULA, LTS SERIES PRINCIPLES OF OPERATION A vibrator, comprising a piezoelectric element attached to a metallic diaphragm, is supported by a die cast case. The vibrator is driven by a self-oscillation circuit. When the vibrator comes into contact with powder, the vibrator’s oscillation is impeded, causing the vibrator to stop and hence the powder to be detected. Two types of outputs are available: The analog output type (direct output of oscillation waveform) and the digital type (output of highlow levels after passing the oscillation waveform through rectifying,...

2-TERMINAL TYPE SEPARATE EXCITATION OSCILLATION FORMULA, TSP SERIES PRINCIPLES OF OPERATION A vibrator, comprising a piezoelectric element attached to a metallic diaphragm, is supported by a die cast case. The vibrator is driven by an external excitation oscillation circuit. When the vibrator comes into contact with powder, the vibrator’s oscillation is impeded, causing the vibrator to stop and hence the powder to be detected. The external excitation oscillator circuit and phase comparator circuit etc. are driven by a TDK custom chip. These products are available in two types: The "External chip"...

IC SEPARATED TYPE SHAPES AND DIMENSIONS SENSOR CIRCUIT DIAGRAM Sensor control circuit – Side pattern Sweep oscillator Phase detection IC SEPARATED TYPE PRECAUTIONS • Shorten the connection distance between the sensor and IC block as much as possible. This distance must not exceed 250mm. • Observe the polarity of the sensor block. • Consult with TDK when using this product. Reversible 6 the polarity SL(to GND or VDD) 5 OUT • All specifications are subject to change without notice. 002-02 / 20120215 / eb461_ts.fm

PIEZO-TYPE LEVEL SENSORS BASIC PRINCIPLES OF OPERATION The basic structure and principles of operation of a piezoelectric vibration type sensor are the same as those of a piezoelectric sounder. The most generally used vibrator "unimorph" structure comprises a thin piezoelectric disk, which has electrodes formed on both surfaces, attached to a thin metal diaphragm (Fig.1). Fig.1: Structure of 3-terminal piezoelectric unimorph vibrator Metal diaphragm (Vibrator) Piezoelectric disk Since the sensing diaphragm surface will be exposed to powder and must be wiped periodically, the piezoelectric vibration...

3-TERMINAL TYPE POWDER LEVEL SENSORS Metal diaphragm Piezoelectric disk Fig.6: Electrode structure of 3-terminal piezoelectric vibrator Fig.8: Frequency characteristics of gain and phase change with a contact load to be applied to piezoelectric vibrator surface PRINCIPLES OF OPERATION The three-terminal type powder level sensor is equipped with a primary electrode and an output electrode on the piezoelectric ceramic. The self-oscillation method is used to vibrate the perimeter-supported unimorph at its innate vibration frequency. The unimorph structure utilized for this is shown in Fig.6. Self-oscillation...

2-TERMINAL TYPE POWDER LEVEL SENSORS Metal diaphragm Piezoelectric disk In contrast to the three-terminal type powder level sensor, the vibration does not stop even after a load is applied since the vibration is caused by an external AC signal. The changes in unimorph characteristics are used to distinguish whether or not a load is applied to the sensor diaphragm surface. In the equivalent circuit diagram shown in Fig.11, Cd denotes electrostatic capacitance, L0 denotes equivalent mass, C0 denotes the inverse number of the equivalent stiffness and R0 denotes equivalent mechanical resistance....

PRECAUTIONS [ALL TYPES] • An extremely thin metal sheet and piezoelectric element are used for the toner sensor detector surface. Therefore the sensor detector surface must be handled carefully to make sure that it is not subjected to mechanical stress. • Grounding and other measures must be considered because the sensor circuitry and piezoelectric element can be damaged by surges and static electricity. [3-TERMINAL TYPE] • A ground should be connected to the case of the LTS type during operation to prevent the case from changing potential. [2-TERMINAL TYPE] • Make sure that the OFF time of the...