Ein Beitrag zur Entwicklung und Optimierung von Bauformen und Fertigungstechniken piezoelektischer Relais
Karsten Pietsch
ISBN 978-3-89722-368-4
150 pages, year of publication: 2000
price: 35.00 €
Summary
In literature the realization of a piezoelectric relay is already discussed
since many years; however this device is not produced industrial in large
numbers. This elaboration is a contribution to clarify the state of the art
and to inquire into the research of this electromechanical component. With
new ceramic materials and a new technology of multilayer a new approach to
realize a piezoelectric relay is created.
First of all some characteristics of classical relay as a solution for
switching tasks are pointed out. A mechanical contact can change by opening
and closing a circuit from a very little contact resistance lesser then 1
mOhm to a very big almost infinite resistance of over 10 GOhm. Based on this
characteristic not yet reached by semiconductor and other advantages the
electromechanical relay has its interest on market.
The electromechanical relay uses as an alternaltiv drive a piezoelectric
actuator.
The type of construction of the piezoelectric actuator is a bending element,
because this one reaches the necessary displacement for an electrical
contact in the scale of a miniature relay. The actuators large signal
behaviour is tested with a series of novel sample actuators manufactured in
multilayer technology.
The theoretical fundamentals of the piezoelectric drive and its experimental
verification are implemented refering to the suitability and operation in a
electromechanical relay.
With a special developed force measurement unit the small actuating force
can be determined for a long time and without parasitic displacement of the
measured position, such as orginated by coupling a measurement force spring.
The defined and measured characteristics are used to analyse the possible
relay constructions.
The systematic approach for the type of construction of a piezoelectric
relay has the target to realize a piezo-relay that can be tested as an
prototype in laboratory.
For this reason the laboratory construction uses materials which can be used
in large numbers.
A known method for utility value is used to determine the best suitable
construction of the worked out concept variants and this construction is
realized as a short run.
It is elaborated a calculation for dimensioning, which can be used to design
a piezo-relay with a bending element and an additional element for storing
mechanical energy.
With the example of a test plan measured on the function samples
characteristics of a relay are achieved which can be compared with a
conventional relay of similar size and can be declared as generalised data.
The completion of the elaboration is a survey of possible manufacturing
technique and fields of application of a piezo-relay.