Abstract: A distance measuring device includes a transmitter for transmitting an acoustic signal at a distant object, an acoustic signal receiver for receiving a reflected acoustic signal reflected from the distant object, a temperature sensor detecting air temperature, a humidity sensor detecting air humidity, an amplifier amplifying the reflected acoustic signal, a comparator coupled to the amplifier comparing the amplified reflected acoustic signal with a reference and generating a comparator output when the level of the amplified reflected acoustic signal exceeds the reference, a gain controller increasing the gain from transmitting an acoustic signal until the comparator output is generated, a threshold generator providing the reference to the comparator and decreasing the reference at an exponential rate from transmitting the acoustic signal until the comparator output is generated, and a controller determining use of only the air temperature, velocity of the acoustic signal, and distance traveled from transmitti

Abstract: A multiple sensitivity stud sensing device for determining a location of objects behind a wall lining has a housing with a surface for moving over the wall lining. Within the housing are a capacitive sensor with first and second capacitances provided adjacent the surface and control circuitry. The control circuitry includes a detecting circuit connected to the sensor for providing a detection signal related to an imbalance between the first and second capacitances, a comparator having a reference signal for providing a comparator signal related to a difference between the detection signal and the reference signal, and a controller for receiving the comparator signal and providing a display signal. A display is provided on the housing for indicating a location of an object behind the wall lining. An input device is provided on the housing so that a user of the device can select a value for the reference signal.

Abstract: A baby monitor has a nursery unit and parent unit. The nursery unit has a controller for generating a privacy code, a microphone for detecting baby sounds and a transmitter for transmitting a signal made up of the privacy code and the baby sounds. The parent unit has a receiver for receiving the signal, a controller for comparing the privacy code to a reference code, and an amplifier and speaker for outputting the baby sounds. The baby sounds are output by the parent unit if the privacy code matches the reference code. The nursery and parent units have a scrambler and descrambler respectively for scrambling the signal.

Abstract: A multiple sensitivity stud sensing device for determining a location of objects behind a wall lining has a housing with a surface for moving over the wall lining. Within the housing are a capacitive sensor with first and second capacitances provided adjacent the surface and control circuitry. The control circuitry includes a detecting circuit connected to the sensor for providing a detection signal related to an imbalance between the first and second capacitances, a comparator having a reference signal for providing a comparator signal related to a difference between the detection signal and the reference signal, and a controller for receiving the comparator signal and providing a display signal. A display is provided on the housing for indicating a location of an object behind the wall lining. An input device is provided on the housing so that a user of the device can select a value for the reference signal.

Abstract: A device for locating an object behind a wall lining includes a housing having a front portion fitting substantially in the palm of a user's hand. Operating switches are located in juxtaposition to the grip portion so as to be operable by the user without substantially altering grip on the housing. The device also includes a sensor including a first capacitor plate and a pair of second capacitor plates. The capacitor plates are arranged serially, and calibrated by a pulse width modulator and integrator. Operating electronics are incorporated into an application specific integrated circuit.

Abstract: A baby monitor has a nursery unit and parent unit. The nursery unit has a controller for generating a privacy code, a microphone for detecting baby sounds and a transmitter for transmitting a signal made up of the privacy code and the baby sounds. The parent unit has a receiver for receiving the signal, a controller for comparing the privacy code to a reference code, and an amplifier and speaker for outputting the baby sounds. The baby sounds are output by the parent unit if the privacy code matches the reference code. The nursery and parent units have a scrambler and descrambler respectively for scrambling the signal.

Abstract: An object sensor for sensing objects hidden from view behind a first wall surface. The object sensor has a housing having a front surface with a display and a rear surface. The object sensor also has a sensing system and provides additional functions. The additional functions can include a distance detector, a computing system working in conjunction with the distance detector to determine the distance between the object sensor and a second wall, a tracking mechanism, and a projector to project a beam at predetermined distances. The object sensor may further have a level or a location marker.

Abstract: A portable device for selectively locating a wooden object, a metal object or a live AC wire positioned behind a wall surface covering when the device is moved along a wall surface is disclosed. Wood is detected by changes in effective dielectric constant, metal is detected by changes in magnetic reluctance and a live wire by detecting modulation signals at mains frequency. The device is controlled by a microcontroller to provide discriminating visual and audible signals when each of the kinds of objects are proximate the device.