30results about How to "Reduce the chance of burning out" patented technology

The invention provides an AB-class audio amplifier power protector, comprising an aluminum wire resistor for detecting currents of output tubes, a micro-current source circuit of a low-voltage transfer current and a current threshold detection module as well as a module for controlling an output drive current. The audio amplifier power protector is mainly characterized in that the aluminum wire resistor is used to detect an output current and starts an overcurrent protection function; and the differential pressure of output tube CEs is used to control the output overvoltage protection of the output current. An output overcurrent protection module mainly uses the reduction voltage of the current of the output tubes on the aluminum wire resistor to actuate the micro current source output current to be enlarged; when the current is more than a threshold value, a current mirror works and outputs part of drive current after the output tubes are pulled off, thus realizing the restriction ofthe output current; and the output overvoltage protection uses two divider resistors which are connected between the output tube CEs in parallel, when the voltage on the low resistor is enlarged, theoutput current of the micro current source module is changed, thus reducing output of the drive current, thereby avoiding that the output tubes output too large currents when the differential pressure is too large.

The invention belongs to the technical field of cables, and particularly relates to a separation-type lightning protection cable. The separation-type lightning protection cable comprises electric units, an inner jacket, an armoring layer, an outer jacket and a grounding layer; the inner jacket sleeves outside a first protective layer, a second protective layer is arranged outside the inner jacket, the grounding layer is arranged outside the second protective layer, the armoring layer is arranged outside the grounding layer, and the outer jacket is arranged outside the armoring layer; the first / second protective layer is made of a mica tape; and the separation-type lightning protection cable is characterized in that a position fixing element is arranged in the first protective layer, the position fixing element has a plurality of storage holes which are not communicated with each other, the electric units are distributed in the storage holes, and each storage hole is only provided with one electric unit; each storage hole is provided with an opening which is arranged on the edge of the position fixing element, and the electric unit can stretch into the storage hole or be taken out from the storage hole through the opening; besides the opening position, the edge of the position fixing element is positioned on the same cylindrical surface. The separation-type lightning protection cable has the beneficial effects that simplicity in production is realized, the production speed is high, the resistance rate of the grounding layer is low and the maintenance cost is low; the electric power still can be normally transmitted when the cable is provided with high load or struck by the lightning.

The invention belongs to the technical field of cables, and relates to a comprehensive anti-lightning cable, which includes a cable core, an inner sheath, an armor layer, an outer sheath, and a grounding layer; Outside the first protective layer, the inner sheath covers the second protective layer, the grounding layer is located outside the second protective layer, the armored layer is outside the grounded layer, and the outer sheath is extruded and coated outside the armored layer; Both the first and second protective layers are mica tapes; it is characterized in that the cable core is composed of multiple electrical units, central isolation elements, and multiple surrounding isolation elements. The electrical units are composed of conductors and insulating layers; the electrical units are distributed in the central isolation The adjacent electrical units around the element are not tangent; the surrounding isolation element is tangent to both the adjacent electrical units and the first protective layer, and the electrical unit is tangent to the first protective layer or has a gap. The invention has the following main beneficial effects: simple manufacture, fast production speed, lower grounding layer resistivity, lower maintenance cost, and normal power transmission under overload and lightning strike conditions.

The invention discloses a manual board discharging device for reflow soldering furnaces, which comprises a conveying chain (1) for conveying printed circuit boards, wherein the conveying chain meshes with a sprocket (3) transmitted by a transmission shaft (2). The device is characterized in that a one-way bearing (4) is sheathed outside the transmission shaft (2), a reflow soldering power unit (5) is arranged on one side of the one-way bearing, and the reflow soldering power unit transmits the one-way bearing by the chain to drive the transmission shaft. The device can discharge boards by manual operation during power failure without being affected by the force of the retarder of the power unit.

The invention discloses an intraoral orthodontic restoration instrument, which comprises a box-shaped main body of the restoration instrument, and a trapezoidal side wall of the main body of the restoration instrument is provided with a power supply interface for inserting a power supply line. Another group of side walls with a trapezoidal outline of the main body of the restorative instrument is provided with a second quick connector, and the second quick joint is threadedly connected with the main body of the restorative instrument. screen, an operation keyboard is arranged on the slope of the prosthetic instrument main body adjacent to the display screen, and two sets of panel threaded rods are arranged on the upper side of the display screen, and the prosthetic instrument main body is connected with the connecting pipe through the second quick joint, so One end of the connecting pipe facing away from the second quick connector is connected to the first quick connector, and the first quick connector is screwed to the operating device. The main body of the dental internal and external prosthetic instrument can quickly dissipate heat from a driving motor driving a dental drill, and is suitable for popularization and use.

The invention belongs to the technical field of cables, and relates to a lightning-proof optical and electric compound cable for a communication base station. The lightning-proof optical and electric compound cable comprises a cable core, an inner sheath, an armor layer, an outer sheath and a ground layer, wherein the cable core is composed of an optical unit and an electric unit, the cable core is covered by a first protective layer, the inner sheath and a second protective layer, the ground layer is arranged outside the second protective layer, the armor layer is arranged outside the ground layer, the outer sheath is arranged outside the armor layer, and the face, making contact with the ground layer, of the armor layer is a film-free face. The lightning-proof optical and electric compound cable is characterized in that the ground layer is composed of ground conductors, filling bars and a winding layer spirally arranged outside the ground conductors and the filling bars in a covering mode, the ground conductors and the filling bars are distributed outside the second protective layer in a mutually staggered mode, the diameter of the each filling bar is no larger than that of the corresponding ground conductor, the winding layer makes contact with the ground conductors and keeps electrical communication with the ground conductors, and the armor layer is located outside the winding layer. The lightning-proof optical and electric compound cable mainly has the advantages of being easy to manufacture, high in production speed, lower in electrical resistivity of the ground layer, lower in maintenance cost and cost and lighter in weight.

The invention belongs to the technical field of cables and relates to a lightning protected cable for a communication base station. The lightning protected cable for the communication base station comprises a cable core, an inner protecting sleeve, an armor layer, an outer protecting sleeve and a ground layer. The lightning protected cable for the communication base station is characterized in that a first protecting layer is arranged outside the cable core, the inner protecting sleeve is arranged outside the first protecting layer, a second protecting layer is arranged outside the inner protecting sleeve, the ground layer is arranged outside the second protecting layer, the armor layer is arranged outside the ground layer, and the armor layer is coated with the outer protecting sleeve; the armor layer is a single-face film covering steel belt and the face, in contact with the ground layer, of the armor layer is a non-film-covering face; the first protecting layer and the second protecting layer are both mica tapes; the outer protecting sleeve comprises, by weight, the following raw materials of 71 parts of polyethylene, one part of anti-oxygen 1010, 12 parts of aluminum hydroxides, 0.5 part of HK-type antistatic agent, 3 parts of ethyl acetate, 1 part of carbon black, 10 parts of zirconium oxide and 1.5 parts of polyethylene wax. The lightning protected cable for the communication base station has the advantages of being simple in manufacturing, high in production speed, capable of enabling the electrical resisting rate of the ground layer to be low, low in maintaining cost, small in dust adsorption, pressure resistant, and good in flame resistance.