Transducers Kit

Transducers Kit

The Transducers Kit TK2942 covers a wide range of transducers and a number of standard signal processing methods. The range consists of a Measurements Package, containing a comprehensive Instrumentation Module, a Power Amplifier and a Test Rig, plus three self-contained Transducers Kits.

The kits are available separately, for use with the Measurements Package, allowing a complete transducer workstations to be built-up in stages.

Electro-mechanical Transducers Kit TK2941E comprises six linear displacement transducers. It is the foundation kit for the TK2942 range and introduces some basic principles about transducers and the associated instrumentation requirements. The two other kits should be regarded as extensions to it.

Heat Transducers Kit TK2941H provides a heat bar, three thermal transducers and a bimetal switch together with temperature measurement accessories.

Light Transducers Kit TK2941L contains an optical detector assembly, three photoelectric devices and a selection of optical filters.

The transducers utilise a variety of physical properties, so that in total a very comprehensive treatment of the subject is achieved. Each transducer is treated individually and then, using the measurements package, it is shown how they integrate into complete systems. Mathematics is kept to a minimum level consistent with that necessary to cover the subject adequately.

The coverage is equally suitable for fields of Electronic and Electrical Engineering, Chemical Engineering, Process Control, Physics and Mechanical Engineering. The student manual contains twenty-eight assignments, covering the use of all three kits, each of which include relevant theory and practical discussions as well as the assignments.

The Transducers Kit, together with all the necessary test equipment, is available as TK2942-1 Complete Transducers Kit which includes Power Supply 01-100.

For Light Transducers a light source is provided by a lamp which attaches to the movable platform of the linear transducer test rig. The transducer box contains a Photoconductive cell, Photodiode, Phototransistor and the mechanical arrangement permits each transducer to be rotated at right angles to the optical axis of the rig so that polar response curves can be obtained for each device. By adjusting the distance between the lamp and transducer, an output voltage/intensity characteristic may be plotted. A set of colour filters is provided. These clip over the window of the transducer box to enable the spectral responses of the various transducers to be measured. The theory and operation of each device are fully described in the manual.

For the Electromechanical Transducers, Six linear displacement transducers are provided, each of which mounts onto the Test Rig. The Test Rig carries a movable platform which supports a micrometer. This is used to provide the transducer displacement, the whole platform being moved to provide large displacements.

The following linear transducers are provided:- Linear Variable Resistor, Variable Area Capacitor, Variable Distance Capacitor, Variable Inductor with sliding rod carrying a ferrite slug core, Linear Variable Differential Transformer (LVDT) - This uses a sliding core similar to the variable inductor and is used in conjunction with a phase-sensitive rectifier housed in the instrumentation module. A Strain Gauge is supplied in addition to the linear displacement transducers, a Probe Assembly is provided for liquid depth measurement. This is intended to be used in salt water where variations in depth or salt concentration vary the resistance between the probes. The resistive transducers are used either in a Wheatstone Bridge or in the feedback loop of an operational amplifier. The capacitive and inductive transducers are used as frequency determining elements in an oscillator circuit. The inclusion of a discriminator and amplifier in the Instrumentation Module enables a complex FM system to be constructed. TK2941E, together with the Measurements Package TK2941M is available as an Introduction to Transducers Kit TK2941.

For the Heat Transducers the test mount for the temperature transducers consists of a heat bar which is equipped with a heater at one end and a multi-finned heat sink at the other. The temperature gradient produced along the bar is utilised to explore the characteristics of a number of transducers. These are attached to the bar in the desired position by a clip. Calibration is achieved by means of a mercury in glass thermometer dipped into a water tank which may also be clipped to the bar. An auxiliary heater is provided which may be used in conjunction with the power amplifier to perform closed-loop temperature control experiments. Provided for these assignments are: Thermistor, Platinum resistance, Thermocouple, Bi-metallic switch. The manual explains the use of analogue transducers as temperature measuring devices together with the use of the thermistor in a continuous temperature control system. The switching device is used to demonstrate on-off control of a heater.

The measurements package consists of an Instrumentation Module with four separate sections which may be configured to form sub-systems using the patching leads provided. The Wheatstone Bridge is equipped with selectable ratio arms of 100, 1k, 10k and 100k, a reference potentiometer and a detector short circuit push-button switch.

The Operational Amplifier module contains a differential amplifier with switched gains of 1, 10, 100 and 1000. The switched-gain amplifier is used as a general purpose amplifier; the differential input permitting its use with the Wheatstone Bridge. The Oscillator is designed for use with the inductive and capacitive transducers as frequency determining elements. The centre frequency is 465kHz. The Discriminator is a FM discriminator used in conjunction with the oscillator module. Also included are the components for a phase-sensitive rectifier. The Power Amplifier is a unity gain power amplifier with an output capability of 4 watts.

• Features

  • Bench-top study of transducer applications
  • 28 proven student experiments
  • Text covers theory, practice and industrial applications
  • Employs 14 common industrial transducers
  • Inclusive AC and DC instrumentation sections
  • Suitable for most engineering disciplines

• Curriculum Coverage

  • Wheatstone Bridge
  • Amplifiers
  • Liquid Depth and Resistivity
  • Displacement
  • Strain
  • Wheatstone Bridge for Capacitance
  • Variable Area and Distance Capacitive
  • Use with an Oscillator and Discriminator in FM Systems
  • Electromagnetic Inductance
  • Variable Inductance Transducer
  • Mutual Inductance Transistor
  • Linear Variable Differential Transformer
  • Transducer Circuits
  • Heat Distribution
  • Thermocouples
  • Thermistors
  • Resistance Thermometers
  • Temperature Control (on/off)
  • Temperature Control
  • The nature of Light
  • Photoconductive Cell
  • Semiconductor Photodiode
  • Phototransistor
  • Spectral Response