A wireless microphone which does not require a separate antenna. A wireless microphone in the form of an elongate housing of nonelectrical conducting material with a microphone unit mounted in one end of the housing and a battery and control switch mounted in the other end of the housing. A first electrical circuit including an audio amplifier and a second electrical circuit including a radio frequency amplifier are mounted in the housing physically separated from each other and interconnected b...

A wireless microphone having an on/off safety switch, and a mute safety switch. The microphone includes a generally elongated handle, having a slit-like elongated slot, disposed on the side of the microphone, for substantially entirely housing an on/off control button and detent, and a mute control button and locking detent, out of contact with the user's fingers, in order to prevent inadvertent manipulation thereof.

A wireless headphone in which an infra-red light signal transmitted from a transmitting apparatus is received and reproduced as an audible sound by a headphone unit portion. A first light receiving element is provided on a top portion of a head band portion of the headphone so that, when a listener wears the wireless headphone, a light receiving surface included in the first light receiving element is directed rearward. Second and third light receiving elements are provided on the pair of headph...

A wireless alarm system suitable for home and office use which includes transmitter and receiver assemblies. Two types of transmitters are includeable in this system, with one of said transmitters providing an alarm signal of a predetermined duration while the other of said transmitters selectively provides an alarm or an inhibit signal, each having different durations. The second of the transmitters may be portable, and both transmitters can send coded signals to the receiver which includes a d...

A wireless receiver has an FM receiver for receiving an infrared radiation modulated by an audio signal. The received infrared radiation is demodulated into the audio signal, which is then supplied through a power amplifier to a loudspeaker unit or a headphone unit. The wireless receiver includes a detector for detecting whether or not the infrared radiation is received. An output signal from the detector is used to turn the power supply of the FM receiver and the power amplifier on or off. The ...

A wireless detonator is disclosed that includes an antenna for receiving microwaves, a detonator provided with a heating element, and a transmission circuit. The heating element in the detonator is heated by the energy of the microwaves. The transmission circuit transmits the microwave energy from the antenna directly to the heating element. The antenna has a relative gain of 0 to 20 dB in the frequency band of the microwaves. The absolute value of the reactance component in the radiation impeda...

A wireless microphone assembly is disclosed which uses a frequency modulated transmitter having improved radiation characteristics and eliminates the need for a separate external antenna. An adapter unit is disclosed as being connectable to a conventional microphone with the adapter unit including a transmitting oscillator having its input circuit coupled with the conventional microphone output circuit via plug connectors and with the output circuit of the frequency modulated oscillator being co...

1. In a system for jamming wireless communications with the aid of a searching receiver for ascertaining senders which are engaged in the transmission of messages, a powerful jamming transmitter for radiating jamming signals on the waves of ascertained senders, whereby said receiver and transmitter are alternately operative to ascertain transmitting senders and to transmit jamming signals, respectively, which comprises means at the searching receiver for converting received frequency signals int...

A double-hung window mounted alarm actuating unit comprises a transmitter for generating wireless signals, a relative constant voltage power source connected to the transmitter, and switch means mounted to the bottom and top windows operable upon the opening of either the bottom or top window for actuating the transmitter to generate a wireless signal for a relatively short period, whereby the transmitter draws power from the power source only during the relatively short period. Switch means clo...

A wireless paging receiver to be called up individually or as member of a group of receivers by a binary modulated carrier frequency call telegram. Each call telegram contains an address. Each individual address is composed by code words selected from a certain number of patterns. In a group call address one or more code words are replaced by a group call pattern, so that all receivers are called whose addresses contain the remaining code word patterns. For coding the address in the receiver onl...