264 results about "Current clamp" patented technology

The invention discloses an improved opening-closing structure of a clamp pressure cooker. A current clamp type pressure cooker has the problem that a clamp is prone to being self-reset commonly, the pressure cooker can exert pressure under the condition that a cooker body and a cooker cover are not completely buckled by the clamp, and a danger exists in case of improper usage. The improved opening-closing structure of the clamp pressure cooker is characterized in that a rack is fixedly connected to the center of the upper surface of the cooker cover and is provided with a bottom plate and two side plates; a gear shaft is fixedly connected to the bottom plate or the cooker cover and is sleeved by a gear; a swing piece is arranged at the tops of the two side plates of the rack and swings left and right by taking the upper part of the swing piece as a fulcrum; the lower part of the swing piece is connected with a transmission rod through a central shaft; the bottom end of an opening button and the bottom end of a closing button cooperate with the swing piece. According to the improved opening-closing structure of the clamp pressure cooker, the clamp is prevented from being self-reset, the pressure cooker can exert the pressure under the condition that the cooker body and the cooker cover are not completely buckled by the clamp, and the safety of the pressure cooker in the using process is improved.

The invention relates to a cable conductor DC resistance on-line detection device and a method thereof, aiming at solving the problems of the prior art that detection to a cable conductor needs to cut a section of the cable conductor, which brings inconvenience to operation and causes material waste; the detection is apt to be influenced by air humidity, air temperature and sample temperature and other factors; and the accuracy of detection results is low. The cable conductor DC resistance on-line detection device comprises a resistance tester, a mobile trolley, a potential clamp and a current clamp, wherein the resistance tester is arranged on the mobile trolley; a water tank for containing cables is arranged on the top end of the mobile trolley; the potential clamp and the current clamp are used for clamping cables and connected on the resistance tester through wires. The invention has the advantages of optional movement, convenient use, waster reduction and high detection structure accuracy.

The invention relates to a two-way low-voltage punch-through transient voltage suppression diode which comprises a silicon chip consisting of five areas from bottom to top, wherein metal electrodes are formed at both the front and the back of the silicon chip, and the five areas comprise a first area which is an n+ underlay with the doping of n type, a second area which is a p+ buried layer with the doping of p type, a third area which is a p- epitaxial layer with the doping of p type, a fourth area which is a p+ emitting area with the doping of p type, and a fifth area which is an n+ emitting area with the doping of n type, wherein the second area horizontally overlaps half of the first area; half of the third area is arranged on the first area and the other half of the third area is arranged on the second area; the fourth area horizontally overlaps half of the third area and is opposite to the position of the second area; and half of the fifth area is arranged on the third area and the other half of the fifth area is arranged on the fourth area. The diode has the advantages of low punch-through, voltage and capacitance, large current, excellent clamping performance, surface punch-through resistance and uniform forward and inverse electrical characteristics.

A multi-meter performs multiple measurement functions and includes a housing with a longitudinal axis and a measurement display. The multi-meter further includes a clamp arm type current measuring instrument. The clamp arms are generally aligned with the longitudinal axis of the multi-meter housing. The multi-meter also includes a non-contact infrared temperature measurement device contained in a module attached to the stationary clamp arm of the current measuring instrument. The module is arranged so that the non-contact infrared temperature measurement instrument receives a cone of infrared energy along the longitudinal axis and the cone of infrared energy is not obstructed by the housing or clamp arms.

The invention discloses a method for testing radiated noises of a digital gravity metering device, which comprises the following steps of: calculating corresponding transfer impedance according to a high-frequency current clamp structure; putting a measuring loop in the high-frequency current clamp on a power cord of the digital gravity metering device so as to extract a first noise voltage and a second noise voltage in the power cord; performing a vector operation and a vector difference operation on the first noise voltage and the second noise voltage by using a noise separation network so as to obtain a difference mode conducted noise voltage and a common mode conducted noise voltage; performing operation on the difference mode conducted noise voltage, the common mode conducted noise voltage and the transfer impedance of the high-frequency current clamp to obtain a difference mode conducted noise current and a common mode conducted noise current; and acquiring an electric field which emits the radiation noises in a free space according to a common mode noise current formula. In the method, the common mode noise current of a single-chip digital gravity metering device is measured by using the high-frequency current clamp and the noise separation network, and the radiated noises are predicted through the common mode noise current.

The invention discloses an asynchronous motor rotor broken bar fault judgment method with electric signals and vibration signals integrated, which belongs to the field of motor fault judgment. The method comprises the following steps: an acquisition instrument acquires voltage and current data through a current clamp and a voltage clamp, current spectrum analysis is carried out, if the current signals are normal, no broken bar fault happens to the motor rotor, and if the current signals are abnormal and when one side band appears at each position with a twice slip frequency difference from a power frequency, the next step is carried out; voltage spectrum analysis is carried out, if the voltage signals are normal, no broken bar fault happens to the motor rotor, if the voltage signals are abnormal and when one side band appears at each position with a twice slip frequency difference from the power frequency, vibration signal analysis is carried out, and whether broken bar fault happens to the motor is judged. In view of the problem that error judgment exists in a motor current signal analysis method in the asynchronous motor rotor broken bar fault in the prior art, a mode of sequentially judging the stator current, the stator voltage and the vibration signals is adopted, the rotor broken bar fault is detected, and the error judgment rate is reduced.

The invention discloses a detection method of the handheld terminal for detecting automatic welding equipment. The handheld terminal is provided with a data analysis and diagnosis module and a data collection module, wherein the data analysis and diagnosis module comprises a processing chip and a field-programmable gate array, the data collection module is provided with an analog-to-digital conversion circuit, the analog-to-digital circuit is respectively connected with an automatic welding equipment controller, a current clamp, a mutual inductor and a camera through signal lines, the handheld terminal is provided with a remote monitoring module, a storage module, and a communication module and a display module. The method adopting the terminal for detecting the welding equipment comprises the steps including terminal self inspection, equipment connection, parameter setting, signal processing, result display, remote detection, system upgrading and the like. The terminal has the characteristics that the size is small, the functions are rich, and the response speed is high. The detection method can be used for fast and precisely detecting the power supply quality of the automatic welding equipment and the operation quality in the welding process.

A handheld instrument that accomplishes infrared (IR) temperature measurement and non-contact electrical current measurement. The instrument has a case, a current-sensing device coupled to the case and operable to be placed around a conductor, for generating an output signal based on the current flowing through the conductor, and an IR detector carried by the case, for sensing IR energy emitted from a surface being measured along a sensing axis that extends from the case, and generating an IR output signal. Sensed IR energy is converted to a temperature value, and the output signal from the current-sensing device is converted to at least a measured current value. There is a display device in the case, for displaying instrument measurements to the user.

The invention relates to a portable protection device for post-failure live treatment of a protection device of a distribution network system and a live treatment method thereof, and the portable protection device comprises a current clamp clamped on the connection line between the secondary side of a current transformer and a terminal block, a sampling module for collecting current on the current lamp, a control module connected with the output end of the sampling module and a tripping relay connected with the output end of the control module, wherein the tripping relay is used for connecting with a switch tripping control loop, when failure occurs in the protection device, the tripping relay is put into the connection with the switch tripping control loop under drive of the control module so as to enable the portable protection device to replace the protection device for being put into operation temporarily. As live working treatment is adopted during one equipment interval corresponding to the failure protection device, the workflow is simplified, the working efficiency is improved and the safe operation level of a power grid is not affected.

The invention provides a flexible clamp, which aims at overcoming the disadvantages of the existing clamps, which are too large to be suitable for clamping small aviation blades, complex in system, easy to cause deformation and errors, etc.; the flexible clamp of the present invention includes blade body support mechanism, The clamping mechanism, the rotary height adjustment mechanism and the angle tilting mechanism, by adjusting the working angle of the angle tilting mechanism, the flexible clamp can adjust the tilt angle of the blade. The flexible clamp of the present invention can clamp and support the blade body to a certain extent, prevent the blade body from being deformed during processing and cause errors, is universal, flexible and adjustable, and is suitable for different blades with large differences in blade body and different curved surface shapes.

The invention discloses an earth fault detection device for a direct current system. The device comprises a signal generating module, a fault analyzing module and a fault positioning module; the signal generating module is used for setting a working mode of the fault analyzing module, generating a current signal which is matched with the working mode and has the set frequency and amplitude and injecting the current signal into the direct current system; the fault analyzing module is used for sampling varying voltage of a bus of the direct current system, judging whether an earth fault exists in the direct current system and synchronously transmitting the sampled voltage and the current signal which has the set frequency and amplitude to the fault positioning module; the fault positioning module is used for sampling a branch circuit leakage current in the direct current system through a direct-current current clamp meter or alternating-current current clamp meter and performing fault positioning processing according to a sampling result and the data synchronized by the fault analyzing module. According to the earth fault detection device for the direct current system, a user can conveniently perform switching using between a direct current mode and an alternating current mode according to the self demand, and therefore the earth fault in the direct current system can be accurately and reliably detected out.

A current clamp meter includes a current meter body and a jaw assembly. The jaw assembly is configured so that the current clamp meter may be used to reach and readily single-out a desired wire from amongst adjacent wires.

The invention provides a double tip rotary mill clamp which solves the problem that the blade is clamped unstably due to the fact that the extending length of a single tip for the current clamp cannot be adjusted, so as to ensure the profile machining quality of the blade and improve the machining speed as well as solve the problem of poor universality and high tool cost. The double tip rotary mill clamp comprises a tip base and two positioning tips. The two positioning tips are installed on the tip base in parallel. The tip base is installed on a numerically-controlled machine tool. The double tip rotary mill clamp is characterized in that the tip base is integral, and the two positioning tips are installed on the integral tip base through a tip support plate. The integral tip base is internally provided with an adjusting mechanism which adjusts the extending lengths of the two positioning tips simultaneously, wherein the two positioning tips are connected with the adjusting mechanism.

The invention relates to a convective stacking method of a hood-type annealing furnace, in particular to a suspended-type convective stacking method used on the hood-type annealing furnace. The method is characterized in that: first, the inner rings of steel strip rolls are attached with sleeves; second, one steel strip roll is stacked on a charging floor of the annealing furnace, a convective plate is arranged above the steel strip roll in an overlapping manner, the bottom of the convective plate is matched with the sleeve in the steel strip roll, the sleeve supports the convective plate, and the upper surface of the steel strip roll is not contacted with the convective plate; third, the steel strip roll is put on the convective plate in an overlapping manner, the lower surface of the steel strip roll is contacted with the convective plate, and the sleeve in the steel strip roll is positioned on the upper part of the convective plate, so that all the steel strip rolls are installed layer upon layer in an overlapping manner. The convective stacking method can lead only the lower surfaces of the relative steel strip rolls to be contacted with the convective plate, and lead the upper surfaces thereof to be not contacted with the convective plate, thereby solving the problem that the lower layer steel strip rolls are pressed lengthways in traditional equipment; therefore, the bonding incidence rate of the lower layer steel strip rolls is greatly reduced, in addition, the lengthways folding occurrence probability of the steel strip rolls is also reduced correspondingly.

A precision measurement unit (PMU) includes a force amplifier selectively providing either a forcing voltage or a forcing current to a device under test via an output force terminal. A low limit voltage clamp and a high limit voltage clamp are operatively coupled to the output force terminal. The low and high limit voltage clamps are each responsive to user programming to define respective low and high voltage limits at the output force terminal. Upon detection of a reversal of said user programming, the operation of the low and high limit voltage clamps is disabled. More particularly, a comparator is adapted to compare the low and high voltage limits and provide a corresponding disabling signal if the high voltage limit is lower than the low voltage limit.

The invention provides a gate drive current charging circuit of a power device and a gate drive control circuit of the power device. The gate drive control circuit separates charge and discharge paths, and uses an adjustable current source to provide charging current for the power device, with more flexible and reliable control mode, which can be applicable to integrated package applications of the power device, especially for depletion-type GaN power transistors. The gate drive current charging circuit is an on-chip adjustable current source with maximum current clamp, and the generated charging current is adjusted by adjusting the voltage value of the reference voltage, the resistance value of the off-chip resistor and the number of strobe current mirror units, so as to ensure more flexible and accurate control of the charging current of the power device. A current control loop is used to realize the maximum current clamping, and a filtering structure is set to eliminate the influence of noise, so as to improve the system reliability. At the same time, when the gate voltage of the power device reaches the logic high level of the gate drive control circuit, the generation of the charging current is stopped, and no additional power consumption is generated. No series resistance is used, so that no gate parasitic inductance is introduced.

The invention discloses a clamp proof detection method of a closed part. The clamp proof detection method of a closed part includes the steps: acquiring the current duty ratio of a PWM (Pulse-Width Modulation) signal which is used for controlling rotation of a motor so as to drive the closed part to take action; according to the current duty ratio and a pre-obtained barrier-free duty ratio, obtaining the current clamp proof force of the closed part; comparing the current clamp proof force with a pre-obtained clamp proof force threshold; and when the current clamp proof force is greater than the clamp proof force threshold, sending a clamp proof signal which is used for controlling the motor to stop or counter-rotate. The clamp proof detection method of a closed part takes the PWM duty ratio signal as a basis for determining resistance change of the closed part, and does not need adding an extra current sampling circuit to determine whether the closed part is obstructed by a barrier, thus reducing the hardware cost.