Abstract: The present invention, generally speaking, provides a time shift angle demodulator that is of simple construction and has an extended linear range. Range extension is achieved by using the input signals directly, not simply post-processing the S-PFD outputs. In accordance with one embodiment of the invention, a method of measuring the phase or frequency of a periodic input signal uses a periodic reference signal and includes comparing the input signal to the reference signal to obtain a lead signal and a lag signal; changing the count of an up/down counter in dependence on the input signal, the reference signal, the lead signal and the lag signal; and using the lead signal, the lag signal and the count signal to produce a phase or frequency signal.

Abstract: A method and apparatus is disclosed for measuring electrical properties of objects by the transmission of electromagnetic waves through a non-magnetizable material. The disclosure also describes a method of measuring changes in electromagnetic signals as the amplitude and frequency of the electromagnetic waves is varied to determine the thickness of an object.

Abstract: A device and method for measuring an impedance between first and second nodes in an electrical circuit without removing components includes at least one current source to provide first and second currents or current signals of known values. First and second probes contact the respective first and second nodes to apply the first and second currents. A third common probe contacts the circuit at a common node that experiences the same current flow as between the first and second nodes. At least one voltage meter measures voltages corresponding to the first and second currents. A processor calculates the impedance based on the known values of the currents, and the measured values of the voltages.

Abstract: An article identification device 4 is mounted on a trap of which operation is diagnosed. The identification device 4 includes a memory 47 in which trap identification data is stored. When the identification device 4 receives an electromagnetic wave from a trap operation diagnosing device, a rectifier 46 derives DC power from the electromagnetic wave, which DC power drives the memory 47 and a modulator 48 so that an electromagnetic wave containing the trap identification data can be sent to the operation diagnosing device. The operation diagnosing device derives the trap identification data from the received electromagnetic wave to identify the trap whose operation the operation diagnosing device diagnoses.

Abstract: According to one embodiment of the invention, there is provided an N-port automatic calibration device comprising N-ports, wherein each port is adapted to be coupled to a port of an N-port multiport test set. The N-port automatic calibration device comprises a single-pole, N−1 throw switch having a single-pole coupled to a first port of the automatic calibration device and having each throw of the N−1 throws coupled to a corresponding port of the automatic calibration device. In addition, the N-port automatic calibration device comprises at least one single-pole, double-throw switch, having a single-pole coupled to a second port of the N-ports of the automatic calibration device, having a first throw coupled to a first load impedance, and having a second throw coupled to a throw of the N−1 throws of the single-pole, N−1 throw switch.

Abstract: An Anode Rod Depletion Indicator for use with a sacrificial anode in a fluid storage tank. A core wire, which is arranged within the anode, has a series of hollow or fluted passageways. When the anode depletion causes a predetermined amount of the core wire to be exposed, fluid contained in the storage tank flows in the hollows or flutes of the core wire. The fluid pressurizes and activates a pressure gauge or switch, or pushes a piston up to a location, which is visible to the owner. In an embodiment, a visible indicator such as “Good” is visible on a pressure gauge until the fluid pressure indicates “Replace” on the pressure gauge or until the piston pushes up a “Replace” indicator to the need to replace anode rod, to prevent corrosion and failure of the tank, while the anode is still providing corrosion protection of the tank. An electrical switch may cut off supply fluid, fuel supply, and/or activate an alarm.

Abstract: An insulation tester and oscillator circuit for use in same includes a transformer including a primary winding and at least one secondary winding to be coupled across an external load such as an electrode. First and second bipolar junction transistors are connected in a “push-pull” operating mode and coupled to the primary winding of the transformer for producing a high frequency voltage. The primary winding has two ends each respective one of which is coupled to a respective one of the collectors of the first and second bipolar junction transistors. First and second field effect transistors are respectively coupled in parallel with the first and second bipolar junction transistors. An actuator for activating the first and second field effect transistors to respectively conduct substantially synchronously with the first and second bipolar junction transistors shortly after start-up is provided, whereby the majority of current is shunted through the field effect transistors.

Abstract: A leakage detector includes a receiver front end having an input for connection with an antenna and a signal path including circuitry for passing a signal from the input without amplification; an IF stage connected with the receiver front end for producing an IF signal therefrom; a detector for producing an AM detected output signal in response to the IF signal; a leak processor for passing only a synchronizing signal of the AM detected output signal, along with harmonic frequencies of the synchronizing signal and DC signals, the synchronizing signal having a peak level, and the signal processor providing an output corresponding to the peak level of the synchronizing signal of the AM detected output signal; a display; and a processing unit connected with the leak processor and the display for displaying leakage data in response to the output signal from the leak processor.

Abstract: A method and self-tuning circuit for tuning vibratory transducers, broadly including electroacoustic speakers and specifically including the speakers of common back-up alarms used for safety reasons on commercial vehicles and heavy equipment. The self-tuning circuit is physically coupled to the transducer's input terminals and operates by comparing the rising and falling edges of one period of a test waveform elicited from the transducer by the application of a test signal having a test frequency. Depending on the results of this comparison, the test frequency is adjusted by predetermined increments upward or downward until the transducer's resonance frequency has been tightly bracketed though not exactly pinpointed.

Abstract: The output of a preamplifier is communicated to an active feedback circuit which drives the primary of a balancing transformer the secondary of which is connected in series with an impedance under test (IUT), the terminals of the series connection are communicated to respective differential inputs of the preamplifier. The feedback circuit automatically drives the preamplifier input toward balance, balance being achieved when the signal across the secondary equals the signal across the IUT in magnitude but opposite in phase. A DC blocking circuit is interposed between the series connection and the preamplifier for blocking preamplifier bias current from loading and heating the IUT. At balance an active equalizing transfer function circuit nulls any potential across the blocking circuit.

Abstract: The invention is relative to a leaktight chamber (3) in which a liquid having electrical characteristics, preferably a conductive liquid, is introduced into a leaktight volume (33) between the cover (5) and the tank (4), and in that a value of electric quantities is measured which varies with the reduction of the liquid contained in the volume (33). In such a way the leaktightness is continually checked.

Abstract: An insulation tester and oscillator circuit for use in same includes a transformer including a primary winding and at least one secondary winding to be coupled across an external load such as an electrode. First and second bipolar junction transistors are connected in a “push-pull” operating mode and coupled to the primary winding of the transformer for producing a high frequency voltage. The primary winding has two ends each respective one of which is coupled to a respective one of the collectors of the first and second bipolar junction transistors. First and second field effect transistors are respectively coupled in parallel with the first and second bipolar junction transistors. An actuator for activating the first and second field effect transistors to respectively conduct substantially synchronously with the first and second bipolar junction transistors shortly after start-up is provided, whereby the majority of current is shunted through the field effect transistors.

Abstract: A switching regulator that has first, second, third and fourth terminals, a first power transistor disposed between the first terminal and a first node, a second power transistor disposed between the first node and a second node, a filter including a capacitor and an inductor, and a controller. The first power transistor is partitioned into a plurality of individually-addressable first transistor segments. The second node couples the second and fourth terminals. The second power transistor is partitioned into a plurality of individually-addressable second transistor segments. The inductor is disposed between the first node and the third terminal, and the capacitor is disposed between the third and fourth terminals.

Abstract: A phase detecting device, including a phase detector, an inversion logic circuit, a latch and an OR logic circuit, is used for detecting the phase difference between a reference signal and a feedback signal and for outputting a delay control signal. The phase detector generates a detected signal according to the status of the feedback signal captured by the reference signal. The inversion logic circuit inverts the detected signal, and the delay device delays the detected signal. The delayed inverted detected signal is then fed into the latch device to generate a latch signal. As the detected signal and the latch signal are fed into the OR logic circuit, the OR logic circuit feeds the delay control signal into the counter so that the delay circuit can generate different delay time, such as T/4, T/2 or 1T, for meeting different signal-delay requirements.

Abstract: An apparatus for detecting flaws in a tire. The apparatus may contain a frame sized to be placed in the interior of the tire, at least one device operably connected to the frame so that upon rotation of the tire the frame travels around the interior of the tire, where the frame is substantially supported by the tire, and at least one pin attached to the frame, where the at least one pin is adapted to be connected to a voltage generator to create an electric field near the surface of the tire when in use so that an electric arc is produced upon the presence of a flaw in the tire.

Abstract: A sensor for an electrostatic detector including an elongated vibratory element supported at a mechanical node at one end in the manner of a cantilever beam, a sensitive electrode on the vibratory element near the other end and adapted to be disposed toward an electrical charge, field or potential being measured, and a driver transducer on the vibratory element for vibrating the element in a direction to vary the capacitive coupling between the electrode and the electrical charge, field or potential being measured. An amplifier and the sensitive electrode are combined in an assembly on the vibratory element thereby providing a low impedance amplifier output which in turn allows a narrow spacing around the vibratory element to prevent entry of contaminants. The vibratory element can be provided with a structure which allows measurements with various spatial resolution characteristics.

Abstract: The likelihood of a system complying with EMC regulations is determined for a system comprised equipment units which individually radiate electromagnetic emissions. The intensity contribution of the electric field from each of the equipment units is calculated and a phase difference is randomly assigned to each of the components repeatedly in order to generate distribution of electric field values between a minium possible electric field value and a maximum possible electric field value. This distribution is then statistically analysed to determine a compliance probability.

Abstract: An on-chip test bus circuit for testing a plurality of circuits and an associated method. The test bus circuit consists of a test bus and a plurality of switching circuits which selectably provide electrical connections between the respective circuits and the test bus. The plurality of switching circuits are configured to transfer an electrical charge between a node disposed within each switching circuit not selected to provide an electrical connection and a respective charge source or sink. The charge source or sink may consist of a low-impedance, substantially noise-free DC voltage or signal source.

Abstract: An apparatus for localized measurements of complex permittivity of a material is provided. A probe (10) analyzes the complex permittivity of a sample (11), the probe (10) having a balanced two conductor transmission line (12) formed of conductive segments (13 and 14). A probing end (15) of the transmission line (12) is brought within close proximity of sample (11) and an opposite end (16) of the transmission line is connected to a terminating plate (17) to form a resonator structure (18) for measurement of the complex permittivity of sample (11).

Abstract: On a semiconductor device 20, fabricated are a VCO 10A, an frequency divider by integer R 21, a frequency divider by integer (P×N+A) 22 wherein each of P, N and A is an integer, A is variable and A<N, a phase comparator 23, and a charge pump 24. A low pass filter 25 having been confirmed to have standard characteristics is externally added to the semiconductor device 20 to construct a PLL circuit to be tested. The frequency divider 22 is of a pulse swallow type and has a control input for setting the integer A at ones in the vicinity of a value in normal use by user. The control input is connected to external terminals D0 and D1 of the semiconductor device 20 for simplifying a test. The semiconductor device 20 is judged whether it is acceptable or not in quality by checking whether or not the PLL circuit enters into a locked state within a given period in each cases of A=A1 and A=A2, where A1<A0<A2 and A0 is a value in normal use by user.