초록 ▼

A wireless audible indication system comprising a transmitter and a receiver. An embodiment of the transmitter includes a modulator formed by a microprocessor and a radio frequency oscillator. The modulation format employed is selectable by the user using severable jumper wires. A battery status cir

A wireless audible indication system comprising a transmitter and a receiver. An embodiment of the transmitter includes a modulator formed by a microprocessor and a radio frequency oscillator. The modulation format employed is selectable by the user using severable jumper wires. A battery status circuit is included which verifies the status of a battery within the transmitter. The modulator transmits a low battery bit to the receiver in order to alert the user of a weak transmitter battery. An embodiment of the receiver includes a superregenerative detector which produces an intermediate signal upon receiving a radio frequency signal. A signal processing circuit, which includes an active peak detector stage and a discrete comparator stage, is used to process the intermediate signal. A microprocessor controls a sound generator circuit in response to the processed intermediate signal. The microprocessor, which normally operates in an inactive mode, is awaken using a wake-up circuit upon reception of the radio frequency signal. A battery status circuit is included to verify the status of a battery within the receiver. Embodiments of the transmitter and receiver employ a pulse position modulation scheme.

대표청구항 ▼

A transmitter for use with a corresponding receiver in a wireless doorbell system, the corresponding receiver capable of receiving a radio frequency signal and producing an audible indication in response thereto, the transmitter capable of operation using a battery source of power, the transmitter c

A transmitter for use with a corresponding receiver in a wireless doorbell system, the corresponding receiver capable of receiving a radio frequency signal and producing an audible indication in response thereto, the transmitter capable of operation using a battery source of power, the transmitter comprising: a battery status circuit, coupled to the battery source, which produces a status signal in dependence upon the status of the battery source, the battery status circuit including a first transistor having a base, a collector, and an emitter, wherein the voltage drop between the base and the emitter varies in dependence upon the voltage of the battery source, and wherein the status signal is based upon the output of the collector, the battery status circuit further including a second transistor having a base, a collector, and an emitter, wherein the collector is coupled to the emitter of the first transistor; a microprocessor, coupled to the battery status circuit, which produces an activation signal to the base of the second transistor to selectively activate the battery status circuit so that the battery status circuit draws current from the battery source only when activated, the activation signal solely for activating the battery status circuit, the microprocessor deriving a battery status bit in response to the status signal from the battery status circuit; and a radio frequency oscillator, responsive to the microprocessor, which produces a radio frequency signal modulated in dependence upon the battery status bit.