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DE473160C
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Overvoltage protection with two electrodes facing each other
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DE509134C
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Electrostatic speaking device
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GB235529A
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Improvements in and relating to loud speakers
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DE425430C
|
|
Loudspeaker telephone
|
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DE438422C
|
|
Electromagnetic speaker
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DE445573C
|
|
Conical or funnel-shaped membrane for speech devices, e.g. loudspeaker telephones
|
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DE474417C
|
|
Transformer for vacuum amplifier
|
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DE371405C
|
|
Process for the production of membranes from pressed sheet metal for speech sets
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|
DE325816C
|
|
Engine for talking machines
|
|
DE472687C
|
|
Adjustable headphone
|
|
DE447408C
|
|
Funnel-free loudspeaker with a conical or curved membrane made of aluminum or a similar material
|
|
DE327625C
|
|
Induction coil, especially for speech currents, with a closed iron circle
|
|
DE425429C
|
|
Vibrating bodies for speech apparatus, especially for telephones, microphones and sound boxes
|
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DE498885C
|
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Conductive coated membrane made of insulating material for electrostatic speech devices
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