Railway microphone switch electronics and device design
Nuutinen, Niko (2020)
Nuutinen, Niko
2020
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2020-11-26
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202011248155
https://urn.fi/URN:NBN:fi:tuni-202011248155
Tiivistelmä
The aim of this thesis work was to design a microphone switch to be used in rolling stock
announcement applications. The device allows to connect up to three microphones into one microphone input one at the time being active.
The base of the design is from a previous project where the similar functionality was achieved using discrete relays. This project has been the starting point for this thesis work and the aim has been to improve this design, add some features and make it into one compact device.
The main functionality of the device is to connect one microphone to the output based on the tangent information from the microphones. The microphone inputs have priorities, one being higher and two being lower. The higher priority is also bypassable to enable more possible applications. In addition to microphone switching, other features are phantom power switching and additional buttons potential-free routing through the device.
The main emphasis of the work was on schematic and layout design. The mechanical design was done by a colleague. The scope of the project was from design phase to first prototype validation. The prototype was validated according to the validation plan to ensure the desired functionality and to find out any design flaws or other areas of improvement.
Since the enclosure did not arrive in time for the testing, ESD-test and mechanical validation could not be performed yet. Other than that the design was proved to work as intended and it met all the requirements. Only minor component value changes are needed which was known beforehand as the values were designed to be fine-tuned with the prototype. In addition, one text label needs to be changed from the enclosure.
As a result the design was successful. After the enclosure arrives the final validation tests can be finished and the prototype is ready for the next phase in productization.
announcement applications. The device allows to connect up to three microphones into one microphone input one at the time being active.
The base of the design is from a previous project where the similar functionality was achieved using discrete relays. This project has been the starting point for this thesis work and the aim has been to improve this design, add some features and make it into one compact device.
The main functionality of the device is to connect one microphone to the output based on the tangent information from the microphones. The microphone inputs have priorities, one being higher and two being lower. The higher priority is also bypassable to enable more possible applications. In addition to microphone switching, other features are phantom power switching and additional buttons potential-free routing through the device.
The main emphasis of the work was on schematic and layout design. The mechanical design was done by a colleague. The scope of the project was from design phase to first prototype validation. The prototype was validated according to the validation plan to ensure the desired functionality and to find out any design flaws or other areas of improvement.
Since the enclosure did not arrive in time for the testing, ESD-test and mechanical validation could not be performed yet. Other than that the design was proved to work as intended and it met all the requirements. Only minor component value changes are needed which was known beforehand as the values were designed to be fine-tuned with the prototype. In addition, one text label needs to be changed from the enclosure.
As a result the design was successful. After the enclosure arrives the final validation tests can be finished and the prototype is ready for the next phase in productization.