Definition of Electromagnetic diaphragm
An electromagnetic diaphragm is a form of capacitive sensor used on an electronic stethoscope. The diaphragm is coated with a conductive material. A conductive plate is positioned behind and parallel to the diaphragm, so that the two conductive elements form a capacitor. Capacitance is a function of plate area, dielectric properties of the space between the conductors, and the distance between the conductors. It is this latter parameter which is modulated by vibration such that the capacitance varies with the distance between the electromagnetic diaphragm and the plate, forming an acoustic sensor.
The electromagnetic diaphragm is a form of capacitive sensor, and shares properties with condenser microphones. The difference between the electromagnetic diaphragm and a condenser microphone is that a condenser microphone operates on the basis of air transmission, has a very thin membrane instead of a diaphragm, and cannot be placed against a body to sense sounds within the body.
The electromagnetic diaphragm for stethoscopes was patented by Clive Smith in 2002 and is used on Thinklabs electronic stethoscopes.
Terms mentioned above
Related terms
Audio crossover
Audio crossovers are a type of electronic filter circuitry that splits an audio signal…
Quasi-peak detector
A quasi-peak detector is a type of electronic detector or rectifier. Quasi-peak…
Loudspeaker enclosure
A loudspeaker enclosure or loudspeaker cabinet is an enclosure (often rectangular…
Mechanical filter
A mechanical filter is a signal processing filter usually used in place of an electronic…
Album era
The album era (sometimes, album-rock era) was a period in popular music, usually defined…
Cardboard record
A cardboard record, commonly referred to as a sound postcard (Polish: pocztówka…
Audio analyzer
An audio analyzer is a test and measurement instrument used to objectively quantify the…
DI unit
A DI unit (direct input or direct inject) is an electronic device typically used in…
Stem mixing and mastering
Stem-mixing is a method of mixing audio material based on creating groups of audio…
Frequently asked questions
What is Electromagnetic diaphragm?
An electromagnetic diaphragm is a form of capacitive sensor used on an electronic stethoscope. The diaphragm is coated with a conductive material.