Abstract: A vehicle anti-theft system includes a four-node bridge network having a removable resistor. The network includes a first resistive segment having a resistance R.sub.1 between a first interface node and a first intermediate node, a second resistive segment having a resistance R.sub.2 between the first intermediate node and the second interface node, a third resistive segment between said second intermediate node and said second interface node having a resistance R.sub.3 and including a removable resistor and a fourth resistive segment having a resistance R.sub.4 between the second intermediate node and the first interface node. The resistances R.sub.1, R.sub.2, R.sub.3 and R.sub.4 satisfy the equation R.sub.3 R.sub.1 =R.sub.2 R.sub.4. The first interface node and the second interface node are electrically connected to the ignition system of the vehicle on either side of the ignition switch.

Abstract: A disaster alert system for a public area, building or the like, each area of which is provided with a sensor responsive to a localized disaster such as a fire with a circuit for each sensor connected to an audio/visual device identified with a specific area, the circuits being connected together so that the response of a sensor in a specific area activates the associated audio/visual device to provide an alerting output which indicates the location of the disaster and measure to be taken at all of the interconnected audio/visual devices.

Abstract: A motor car dashboard, which is compact and has a self contained design and is functionally improved in that the scales of measure of certain magnitudes (e.g. Speed) are divided into staggered sectors corresponding to the most common fields of use, and in that it is possible to take immediate digital readouts of the most important physical magnitudes of interest for a motorist on a display screen, it being sufficient to depress a pushbutton which energizes an electronic readout apparatus for each magnitude of interest and causes the display to be shown on said screen.

Abstract: The present invention provides an acceleration warning and control system for use on motor driven vehicles. The system comprises speed measuring means, acceleration means and an acceleration warning switch, having a variable switch point. Accordingly, the acceleration warning switch is set to switch at different accelerations for different speeds. Generally, the system allows for a higher acceleration at low speeds relative to the acceleration for higher speeds.

Abstract: The plasma matrix display unit comprises a plurality of cathodes perpendicular to a scan anode and to at least one display anode in a gastight enclosure. All the cathodes are positioned on a rear plate. A front plate is transparent at least at the level of points aligned in parallel in the proximity of the display anode. In order to avoid fluctuations of distance between an anode and a cathode during heating operations, longitudinal insulating strips are disposed on the rear plate and form grooves therebetween. The grooves extend under the point lines of the front plate. Each anode is supported on an upper slot of an insulating strip and interacts electrically with the portion of the cathodes emerging from the adjacent groove. The cathodes, insulating strips and anodes are obtained by successive deposition and masking on the rear plate before any further heating. This display unit is designed particularly for the display of large-scale luminous patterns.

Abstract: A circuit for monitoring the voltage across a sensing resistor in series with a load, wherein two reference currents are generated, each dependent both on temperature and on the voltage on a power supply line, which voltage is also temperature-dependent and exhibits a temperature coefficient of such a sense and magnitude that the changes in a reference current due directly to changes in temperatures are substantially offset by the changes in that reference current due to changes in the voltage on its power supply line, which changes are in turn due to the same changes in temperature.

Abstract: Reminders applied to pocketable personal accompanyings such as lighters, pens, ballpens, or pocket calculators, etc. By equipping such objects with mercury-switch-triggered ultramicro buzzers on suitable portion insomuch that an absent-minded owner may be reminded to take them away leaving after having used such objects to avoid indiscreet loss.

Abstract: In an on-board sensible signal that is activated by the speedometer of a vehicle when the vehicle speed exceeds a predetermined threshold and that remains activated when the speed is reduced below this threshold, the improvement consists of a combination of timing and logic circuitry that deactivates the signal when and only when the vehicle stops and remains at rest for a predetermined period of time.

Abstract: A warning circuit which generates signals in response to selected conditions of a vehicle hydraulic brake system. The brake system includes an engine-driven main source of hydraulic pressure, a relay-actuated auxiliary source of hydraulic pressure, a flow sensor for sensing the operation of the main source and a brake switch for coupling the auxiliary source with the battery in response to an operator brake application. The warning circuit includes a first transistor switch coupled with a warning lamp, with the ignition switch and with the auxiliary source. A second transistor switch is coupled to the ignition switch, to the auxiliary relay, to the flow sensor and to the first transistor switch. A third transistor switch is coupled to the ignition swtich, to the flow sensor and to the first transistor switch. The system actuates the auxiliary source upon failure of the main source during an operator brake application.

Abstract: A vehicle level detector detects a change in the elevation of a vehicle body as reflected in a change in the relative distance between a suspension member for wheels of the vehicle and the vehicle body. The detector comprises a magnet and a magnetoelectric transducer element disposed in opposing relationship. One of the magnet and the transducer element is disposed for displacement relative to the other in accordance with a varying elevation of the vehicle body, thus permitting a change in the elevation of the vehicle body to be detected by sensing the displacement.

Abstract: A warning circuit generates warning signals in response to a blown fuse in a vehicle brake system which includes primary and ignition-switch controlled. The back-up pump is driven by an electric motor. Control circuitry monitors and controls the brake system and the fuse protects the control circuitry from ground fault conditions. The warning circuit includes a warning lamp which is connected to the battery via the ignition switch and which is grounded through a transistor switch. The transistor switch is resistively coupled to ground and to the vehicle battery through the fuse so that the transistor switch becomes conducting to actuate the lamp upon the blowing of the fuse. Alternatively, a similar transistor switch may be connected to the output of an astable multivibrator, which in turn is connected to the battery via the fuse and whose output is inhibited unless the fuse blows while the ignition switch is closed.

Abstract: A domestic protective system which utilizes existing household AC power lines to conduct system signals between remote stations or zones and a master receiver. The system signals are established by a single carrier frequency and include a data pulse of this frequency under normal conditions, and no data pulse under malfunction conditions. Locations of zones originating system data signals are identified by time delays established prior to data transmission from each zone, this delay triggered and synchronized by data transmissions transmitted from other zones.

Abstract: An electrical apparatus and method for electrically simulating noise resulting from the thermodynamic expansion of a gas inside a chamber whose volume is varied, is characterized in that it comprises, in series, a capacitor of fixed capacitance and means for varying with respect to time the potential at at least one of the terminals of the capacitor, the potential variation depending on the variation of the volume with respect to time and on the nature of said expansion.

Abstract: A coded security system for an electrical circuit energizing safety lights installed on a vehicle is disclosed. The system comprises a bank of series connected toggle switches which can be operated in one position following a predetermined code for completing an electrical circuit through the terminals of all the switches, means for connecting one terminal of one of the toggle switches to a source of power, and means for connecting one of the terminals of the last toggle switch in the series to the circuit, whereby operation of the toggle switches following the predetermined code will complete the electrical circuit and energize the circuit.

Abstract: A scanning control system is disclosed for remotely sensing or monitoring a predetermined condition or state, such as the presence of a fire, by means of one or a multiplicity of detecting stations at one or a multiplicity of locations with each detecting station providing a positive indication of the location of each predetermined condition sensed. A scanning or control panel is electrically connected with the detecting stations by means of four wires extending from the panel regardless of the number of detecting stations utilized in the system.

Abstract: An oral warning system for monitoring mining operations, or the like, comprising a plurality of first sensors each providing a signal representative of an abnormal condition being sensed, at least one additional sensor providing a signal representing an emergency condition being sensed, an oscillator and modulator for generating an emergency warning tone energized upon detection of the emergency condition, a plurality of speakers at selected locations for broadcasting the emergency warning tone, a multi-track tape player with playback head selectively movable to any one of the track positions and having an audio output connected to local and remote speakers, and circuit means effective to energize the tape player and move its head to an appropriate track containing a prerecorded oral message upon detection of an abnormal condition by one of said first sensors.

Abstract: Electronic theft prevention apparatus including a decoder integrally formed with a vehicle component and selectively enabling the operation thereof, an encoder accessible to a vehicle operator for providing coded instructions to the decoder to enable operation of the vehicle component, and data coupling apparatus for interconnecting the decoder and the encoder to permit data transfer therebetween.

Abstract: A warning device with central indication of operating conditions to be monitored in motor vehicles, with an indicator device which is controllable by a monitoring device. The space for representation of the operating conditions to be monitored that is used is that which is already provided in the dashboard console for indication of the information concerning the clock time.

Abstract: A signaling device for being coupled to a mailbox of the type having a cantelievered tongue section defined below the mailbox door hinge. A snap-type single pole single throw (SPST) push on push off action switch is coupled to the base of the mailbox adjacent to the tongue section of the door for generating a first signal responsive to the operative communication between the tongue section of the door as the door is opened. An electrical circuit is coupled to the switch for generating a sensory perceptible signal responsive to receiving the first signal from the switch. The switch is mounted on a generally U-shaped bracket which may be deformable as the switch is being actuated, thereby reducing the possiblity of damage to the switch as the door is opened.

Abstract: A trouble diagnosing device of a control circuit for receiving, as input signals, signals containing information on controlled means and producing, as output signals, control signals for controlling the controlled means on the basis of the input signals, includes modulator means for modulating the input signals by means of a modulation signal having a trouble diagnosing discrimination waveform, and a trouble diagnosing circuit for producing an output signal indicating trouble in the control circuit system when the output signals of said control circuit systems produced upon receipt of the input signals modulated by the modulator means, contain an abnormal signal.In an embodiment of the invention, the modulator means modulate input signals by means of a trouble diagnosing modulation signal having such a small pulse width that electromagnetic actuators for controlling the controlled means are not able to respond thereto.