34results about How to "Small distribution parameter" patented technology

The invention relates to a high-power self-cooled thyristor valve and a vehicle for assembling the same. The invention is characterized in that: a single-phase thyristor valve body comprises two thyristor valve string, and insulating tension rods, flanges, radiating fins, high-potential trigger plates, energy-taking magnetic rings, high-voltage energy-transmitting cables and a plurality of retaining nuts which are symmetrically distributed; every two thyristors are in positive and negative parallel connection with each other through flexible cables on the radiating fins to form a thyristor valve unit; a plurality of thyristor valve units form a thyristor valve string through parallel connection and upright stacking; radiating fins are pressed between each layer of thyristor valve units at intervals; the two thyristor valve strings form a single-phase thyristor valve through positive and negative parallel connection; both ends of the insulating tension rods are respectively fastened between an upper flange and a lower flange through the retaining nuts; the high-voltage energy-transmitting cables are connected to the inside of the thyristor valve body through the energy-taking magnetic rings of the high-potential trigger plates; the single-phase thyristor valve body inputs and outputs current through two moving contacts; the two moving contacts and the thyristor valve body are fixed together through copper bars which are fixed on the upper end and the lower end of the insulating tension rods through the flanges; and annealed copper sheets which are communicated with the radiating fins are arranged on the copper bars.

The invention discloses a coplanar electrode analog photoelectric detector chip and a manufacturing method thereof. The coplanar electrode analog photoelectric detector chip comprises an epitaxial wafer and an ohm contact layer formed on the rear surface of the epitaxial wafer; the epitaxial wafer comprises a substrate, a buffer layer, an absorption layer, a transition layer, a top layer, a passivation layer, a doped photosensitive area, a limiting channel, an antireflective transition film layer, a P-type electrode metal layer and an N-type electrode metal layer; the top layer is a n-type III-V top layer with at least three elements; the doped photosensitive area is circular; the limiting channel is semi-circular and surrounds the doped photosensitive area. The manufacturing method of the coplanar electrode analog photoelectric detector chip is simple in process and high in finished product rate; the coplanar electrode analog photoelectric detector chip manufactured by the method has the characteristics of low distortion, low dark current, high linearity, high responsibility, high reliability and the like.

An insulation ageing test device of frequency conversion high voltage pulse equipment is prepared as connecting output end of pulse generator to primary edge of high voltage boosting transformer with its secondary edge being connected to wire in insulation sleeve, applying 300H2 to lkH2, 1kH2 to 5kH2 , 5kH2 to 10k H2 and 10k H2 to 20k H2 as operation frequency of high voltage boosting transformer alternately, connecting said boosting transformer to output of pulse generator for outputting square wave to meet requirements of insulation ageing test.

The invention discloses a small and efficient high-power solid-state modulator and belongs to the technical field of pulse power. The modulator comprises a solid-state modulator component and a pulse transformer (T), wherein the solid-state modulator component comprises a direct-current power supply (E1), an energy storage capacitor (C1) and a solid-state switch (V1). The direct-current power supply (E1) is used for charging the energy storage capacitor (C1). Output pulses of the modulator are obtained through the pulse transformer (T) after the energy storage capacitor (C1), the solid-state switch (V1) and the pulse transformer (T) form a discharge circuit. According to the small and efficient high-power solid-state modulator, the single solid-state switch is used, the equalization voltage and the connection consistency of the solid-state switch are not required to be considered, the voltage is low, insulation design can be achieved easily, the output waveform quality of the modulator is greatly improved, the circuit topological structure is simple, the size is small, the efficiency is high, modularization can be achieved easily, and the modulator is applicable to various platforms.

The invention relates to a measuring circuit for moisture content and mineralization degree based on a plug-in impedance sensor. The measuring circuit is used for measuring moisture content and mineralization degree in an oil-water two-phase flow pipeline. The measuring circuit comprises an impedance sensor, a signal processing unit, a demodulation unit and a calculating unit; the impedance sensorcomprises an exciting measuring electrode and two protecting electrodes; the exciting measuring electrode is simultaneously served as an exciting electrode and a measuring electrode; the protecting electrodes are fixed above and under the impedance sensor; the signal processing unit comprises a front-end amplifier, a coaxial cable, an alternating current signal generator and a differential amplifier; a negative input end of the front-end amplifier is connected with the exciting measuring electrode in the impedance sensor through a coaxial cable signal wire; a positive input end of the front-end amplifier is connected with the alternating current signal generator and meanwhile is connected with the two protecting electrodes in the impedance sensor, a shielding layer of the coaxial cable and the negative input end of the differential amplifier; a standard resistor is connected with the negative input end and output end of the front-end amplifier; the output end of the front-end amplifier is connected with the positive input end of the differential amplifier.

Disclosed is an active antenna waterproof radio-frequency connector for a ship. The active antenna waterproof radio-frequency connector comprises a base (11), a first insulator (3) and a contact (1). The active antenna waterproof radio-frequency connector is characterized in that the boss end of the first insulator (3) is inserted into a mounting hole of the base (11), the end face, provided with a boss, of the first insulator (3) abuts against the surface of the base (11), the rod portion of the contact (1) penetrates through a through hole in the first insulator (3) to extend into the base (11), the part, located in the base (11), of the rod portion of the contact (1) is sequentially sleeved with a second insulator (6) and a nut (8), the nut (8) is used for fixing the part, located in the base (11), of the rod portion of the base (11), and a welding terminal (9) is fixed to the end face of the part, located in the base (11), of the rod portion of the contact (1); the other end of the contact (1) is provided with an inner screw hole (20) which is connected with an inner screw of an antenna (14) and external threads (16) which are matched with internal threads (15) on a nut cap (17) for fixing the antenna (14). The active antenna waterproof radio-frequency connector for the ship can be widely applied to waterproof electric connection of various outdoor electronic products, and meanwhile, small distribution electric parameters of contact grounding are kept.

The invention discloses a high-speed avalanche photodetector chip with a carrier and a manufacturing method for the high-speed avalanche photodetector chip. The high-speed avalanche photodetector chip comprises the carrier, a plurality of welding balls welded on the carrier and an epitaxial wafer inversely welded on the welding balls, wherein the epitaxial wafer comprises a substrate, a buffer layer formed on the substrate, an absorption layer formed on the buffer layer, a transition layer formed on the absorption layer, a field control layer formed on the transition layer, a top layer formed on the field control layer, a contact layer formed on the top layer, a diffusion region formed in the top layer and the contact layer, a positive electrode formed on the diffusion region, a negative electrode formed on the contact layer and the buffer layer, a micro-lens formed at the bottom of the substrate, and an antireflection film formed on the surface of the micro-lens; the positive electrode and the negative electrode are welded on the welding balls; the diffusion region comprises a diffusion multiplication region and a diffusion protection ring which are concentric; the radius of the diffusion multiplication region is greater than 15 microns and smaller than 30 microns.

The invention provides an electromagnetic interference-prevention power regulation circuit integrated module and an installation method thereof. The electromagnetic interference-prevention power regulation circuit integrated module comprises a copper-coated ceramic substrate and power regulation circuit components and also comprises a shell, wherein the power regulation circuit components are arranged on the copper-coated ceramic substrate, the copper-coated ceramic substrate and the power regulation circuit components are arranged in the shell, the copper-coated ceramic substrate comprises aceramic layer at a bottom layer and a copper-coated layer at an upper layer, the shell comprises a shell body, an upper cover plate and lead terminals, the shell body wraps bottom surfaces and peripheries of the copper-coated ceramic substrate and the power regulation circuit components, the upper cover plate covers the top of the shell body, and the lead terminals are used for connecting the interior and the exterior of the shell body. The electromagnetic interference-prevention power regulation circuit integrated module has the beneficial effects that a power regulation circuit with relatively serious electromagnetic interference is completely sealed in the shell, the distribution parameter of a power device interconnection loop is reduced, and the electromagnetic radiation of the powerregulation circuit is effectively shielded; and with the adoption of a material with favorable heat conductivity, the thermal resistance between a power semiconductor component and the whole structureis reduced.

The invention discloses a cable for an intrinsically safe explosion-proof ship, which comprises a conductor (1), an insulating layer (2), a packing layer (4), a wrapping band (5), a jacket (7) and the like, wherein a conducting line pair is provided with aluminum-plastic composite tape sub-shields (3), a cable core is provided with an aluminum-plastic composite tape main shield (6), and a drainage wire (8) is arranged at the insides of the aluminum-plastic composite tapes of the sub-shields and the main shield; and by adopting the sub-shields and the main shield structures, the cable for the intrinsically safe explosion-proof ship has small distribution parameter, resists external interference and line-to-line crosstalk, and the drainage wire not only is beneficial to the grounding treatment of the cable, but also can ensure the continuity of a shielding layer.

The invention relates to a moisture content measuring device based on a plug-in conductivity sensor. The moisture content measuring device comprises a conductivity sensor, a signal processing unit, avirtual value measuring unit and a computing unit; the conductivity sensor comprises an exciting measuring electrode which is used as an exciting electrode and a measuring electrode at the same time and two protecting electrodes which are fixed above and under the exciting measuring electrode; the signal processing unit comprises a front-end amplifier, a coaxial cable, an alternating current signal generator and a differential amplifier; a negative input end of the front-end amplifier is connected with the exciting measuring electrode in the conductivity sensor by a coaxial cable signal wire;a positive input end of the front-end amplifier is connected with the alternating current signal generator and meanwhile is connected with the two protecting electrodes in the conductivity sensor, a shielding layer of the coaxial cable and a negative input end of the differential amplifier; a standard resistor is connected with the negative input end and the output end of the front-end amplifier;the output end of the front-end amplifier is connected with the positive input end of the differential amplifier.

The invention relates to a moisture content measuring device based on a plug-in capacitive sensor. The moisture content measuring device comprises a capacitance sensor, a signal processing unit, an effective value measuring unit and a calculating unit. The capacitive sensor includes an excitation and measuring electrode as an excitation electrode and a measuring electrode, and two protection electrodes fixed above and below the excitation and measuring electrode. The signal processing unit comprises a front amplifier, a coaxial cable, an AC signal generator and a differential amplifier. A negative input end of the front amplifier is connected to the excitation and measuring electrode in the capacitive sensor through a coaxial cable signal line. A positive input end of the front amplifier is connected to the AC signal generator and is connected to the two protection electrodes in the capacitive sensor, a shielding layer of the coaxial cable and a negative input end of the differential amplifier. A standard resistor and a capacitor are connected in parallel and are connected to the negative input end and an output end of the front amplifier. The output end of the front amplifier is connected to a positive input end of the differential amplifier.

The invention relates to a high-frequency transformer and a winding method thereof in the field of transformers. The high-frequency transformer comprises a magnetic core, and the magnetic core is provided with two through holes which are arranged side by side at intervals; the number of the conductive sleeves is two, and the two conductive sleeves respectively penetrate through the two through holes; the first cable is wound on the two conductive sleeves of the magnetic core, and the two ends of the first cable penetrate out of the different conductive sleeves on the same side of the magnetic core and are connected with the other conductive sleeve; the second cable is wound on the two conductive sleeves of the magnetic core, and the two ends of the second cable penetrate out of the different conductive sleeves on the same side of the magnetic core respectively. When the transformer is wound, distribution parameters can be reduced, so that matching between the transformer and a circuit is finer.

The invention discloses an epoxy support used for installing a drawer-type power supply module. The support comprises a square shell 1 formed by epoxy plates. A lower surface of shell 1 is provided with a high pressure porcelain bottle 2. The several epoxy plates are vertically installed in the shell 1. An epoxy plate A4, an epoxy plate B9, an epoxy plate C10, an epoxy plate D11, an epoxy plate E12 and an epoxy plate F13 are included. A transformer 3 is installed on the epoxy plate A4 located at a center position in the shell 1. The plurality of transformers are installed on the epoxy plate A4 located at the center position in the shell 1. Copper bars 5 are installed on two sides of the epoxy plate A4 through an insulation support component 6. The transformer 3 provides power through the copper bars 5. Epoxy strips 14 are installed on the epoxy plate B9, the epoxy plate C10, the epoxy plate E12, the epoxy plate F13 and left and right epoxy plates of the shell 1. Power supply modules can be installed on the epoxy strips 14.

The embodiment of the invention provides a data measurement system and method. The system comprises a main control unit, a data measurement module, a data calibration module and a programmed switch module, the data measurement module is used for measuring to-be-measured data of measured equipment to obtain measurement data, and automatic measurement of the equipment is realized; the data calibration module is arranged and used for calibrating the measurement data of the measured equipment, so that automatic calibration is realized; the programmed switch module is used for controlling the connection relation between the data measurement module and the data calibration module and the connection relation between the data measurement module and the tested equipment, so that automatic control of test calibration is facilitated; according to the system provided by the invention, the measurement flexibility and the calibration efficiency and accuracy of the data measurement device are improved, and the influence of factors such as distribution parameters, connection reliability degree and external interference introduced by manual point-by-point connection on data measurement is reduced.

The invention discloses a pulse power synthesis circuit based on constant energy chopping technology. The pulse power synthesis circuit is composed of a chopper loop, a control loop, a transmission loop, and a synthesis loop. The chopper loop and the transmission loop have multiple stages and are connected in parallel between a power supply and the synthesis loop, the chopper loop and the transmission loop of the same stage are in coupling connection through a transformer of the same stage, and circuit structures of the chopper loop of each of the stages and the transmission loop of each of the stages are the same. Circuit components and connection relations of the synthesis loop are that: the right end of an inductor L and the upper end of capacitor C is connected to the upper end of a load R, the lower end of the capacitor C is connected to the lower end of the load R, the left end of the inductor L is an input upper end of the synthesis loop, and the lower end of the capacitor C isan input lower end of the synthesis loop; and two ends of the capacitor C are output ends of the synthesis loop. The pulse power synthesis circuit is adjustable in constant power output and the sizeof power and is adjustable in synthesis waveform frequency and low in waveform distortion factor, can make a switching device work in a soft switching state, does not damage main power devices when anoutput power circuit is short-circuited, and is large in load synthesis power.

The invention relates to a static parameter testing system and method, electronic equipment and a storage medium, and the system comprises at least one of a first measurement module, a second measurement module, a third measurement module, a fourth measurement module, a fifth measurement module and a sixth measurement module. The first measuring module, the second measuring module, the third measuring module, the fourth measuring module, the fifth measuring module and the sixth measuring module are connected with a measuring clamp through a switching module, and the first measuring module, the second measuring module, the third measuring module, the fourth measuring module, the fifth measuring module and the sixth measuring module are connected through a bus. The problems that in the prior art, a solid-state microwave power device static parameter measuring system is inaccurate in measuring result, complex in testing system structure, large in size and heavy in mass are solved.

The invention discloses a pulse shunt which comprises a shell, a check ring, an insulating sleeve, a current terminal, a current end flange, a locking block, a voltage end flange, a voltage terminal,a resistor insulating tube and a shunt resistor disc. The shell and the shunt resistor disc are of a coaxial structure; two ends of the shunt resistor disc are respectively connected with the currentend flange and the voltage end flange; the locking block is used for pressing the shunt resistor disc, so that the shunt resistor disc is tightly connected with the current end flange and the voltageend flange; the voltage terminal is positioned at the bottom of the pulse shunt; and the resistor insulating tube is positioned in an internal gap of the pulse shunt and is used for supporting the shunt resistor disc so as to keep the overall stability of the pulse shunt.

The invention relates to the technical field of a component structure and particularly relates to a LRC component structure. The LRC component structure comprises the steps that: two metal support electrode plates are arranged on the element end electrode for electric connecting and fixing and buffering roles; two electrode plate supports are provided with a derivation pin derived inward or outward in the bottom; the derivation pin is fixedly connected to a circuit board; multichip LRC elements which are in series connection or parallel connection are soldered inside the two electrode plate supports. The multichip resistance capacitance element is vertical stack installation or horizontal stack installation. According to the corresponding principle or function of circuit, corresponding pins are only soldered on a bonding pad at using time, the LRC element bodies not touch the bonding pad, the impacts made by undesirable stress such as mechanical stress, temperature stress and the like are reduced by the buffer function of the electrode plate supports, the reliability for the LRC components is increased. The elements installation occupancy area is effectively saved through the stack component modular structure, and the line distribution parameter is reduced at the same time.

The invention provides an electromagnetic interference-prevention power regulation circuit integrated module and an installation method thereof. The electromagnetic interference-prevention power regulation circuit integrated module comprises a copper-coated ceramic substrate and power regulation circuit components and also comprises a shell, wherein the power regulation circuit components are arranged on the copper-coated ceramic substrate, the copper-coated ceramic substrate and the power regulation circuit components are arranged in the shell, the copper-coated ceramic substrate comprises aceramic layer at a bottom layer and a copper-coated layer at an upper layer, the shell comprises a shell body, an upper cover plate and lead terminals, the shell body wraps bottom surfaces and peripheries of the copper-coated ceramic substrate and the power regulation circuit components, the upper cover plate covers the top of the shell body, and the lead terminals are used for connecting the interior and the exterior of the shell body. The electromagnetic interference-prevention power regulation circuit integrated module has the beneficial effects that a power regulation circuit with relatively serious electromagnetic interference is completely sealed in the shell, the distribution parameter of a power device interconnection loop is reduced, and the electromagnetic radiation of the powerregulation circuit is effectively shielded; and with the adoption of a material with favorable heat conductivity, the thermal resistance between a power semiconductor component and the whole structureis reduced.

The invention relates to a high-power IGBT (insulated gate bipolar transistor) driver. A wire passes the centers of all of n transformers and serves as a primary winding for the n transformers. Each transformer comprises a secondary winding independent. Winding directions of the secondary windings are identical; the secondary windings are equal in the number of turns. The secondary windings are all connected in parallel. The secondary windings of the transformers are parallelly connected for outputting; great instantaneous output current can be provided; load carrying capacity is high; a distribution parameter is diminished; wide and narrow pushes are both considered; an IGBT can be on or off at higher speed; on and off loss of the IGBT is reduced. A drive circuit and a main circuit are isolated through the transformers; reliability of the drive circuit is greatly enhanced; damage of the drive circuit caused by failure of the main circuit is effectively prevented. Devices in secondary winding loops are all passive devices, no auxiliary power is required, the circuits are simple, fewer devices are used, circuit complexity is reduced, and parasitic interference is avoided.

The invention discloses a coplanar electrode analog photoelectric detector chip and a manufacturing method thereof. The coplanar electrode analog photoelectric detector chip comprises an epitaxial wafer and an ohm contact layer formed on the rear surface of the epitaxial wafer; the epitaxial wafer comprises a substrate, a buffer layer, an absorption layer, a transition layer, a top layer, a passivation layer, a doped photosensitive area, a limiting channel, an antireflective transition film layer, a P-type electrode metal layer and an N-type electrode metal layer; the top layer is a n-type III-V top layer with at least three elements; the doped photosensitive area is circular; the limiting channel is semi-circular and surrounds the doped photosensitive area. The manufacturing method of the coplanar electrode analog photoelectric detector chip is simple in process and high in finished product rate; the coplanar electrode analog photoelectric detector chip manufactured by the method has the characteristics of low distortion, low dark current, high linearity, high responsibility, high reliability and the like.

An insulation ageing test device of frequency conversion high voltage pulse equipment is prepared as connecting output end of pulse generator to primary edge of high voltage boosting transformer with its secondary edge being connected to wire in insulation sleeve, applying 300H2 to lkH2, 1kH2 to 5kH2 , 5kH2 to 10k H2 and 10k H2 to 20k H2 as operation frequency of high voltage boosting transformer alternately, connecting said boosting transformer to output of pulse generator for outputting square wave to meet requirements of insulation ageing test.

The invention provides a six-terminal network-type kilowatt-class radiofrequency power resistor. The six-terminal network-type kilowatt-class radiofrequency power resistor comprises a flange plate andsubstrates, further comprises A surface electrodes, B surface electrodes and side surface electrodes, and further comprises medium protection layers, wherein the A surface electrodes are arranged onthe upper surfaces of the substrates; the B surface electrodes are arranged on the lower surfaces of the substrates; the side surface electrodes are arranged on the side surfaces of the substrates andare connected with the A surface electrodes and the B surface electrodes; resistor bodies are positioned on the A surface electrodes and are ensured to be stably overlapped with the overlapping endsof the A surface electrodes; the medium protection layers cover the resistor bodies and play a protective role; metal leads are welded to the A surface electrodes by a welding technology; packaging cover plates are adhered to the upper surfaces of the substrates through high-temperature adhesive. The six-terminal network-type kilowatt-class radiofrequency power resistor has the advantages as follows: by a principle of hierarchical derating, the three substrates bear certain power respectively, so that a phenomenon of heat accumulation caused by power concentration on a single substrate is avoided and the power bearing capability of the whole resistor is greatly improved; overall distribution parameters of the resistor are reduced, so that the frequency characteristics of the resistor are improved.

A marine active antenna waterproof radio frequency connector, which includes a base (11), a first insulator (3) and a contact (1), characterized in that the boss end of the first insulator (3) is inserted into the base (11 ), one end surface of the first insulator (3) with a boss is against the surface of the base (11), and the rod of the contact (1) extends into the base through the through hole on the first insulator (3) In (11), the second insulator (6) and the locking device for fixing the rod of the contact (1) located in the base (11) are successively set on the rod of the contact (1) located in the base (11). A nut (8), with a solder piece (9) fixed on the end surface of the rod of the contact (1) located in the base (11); the other end of the contact (1) is provided with an inner The inner threaded hole (20) connected with the screw rod and the outer thread (16) matched with the inner thread (15) on the screw cover (17) of the fixed antenna (14). The invention can be widely used in the waterproof electrical connection of various outdoor electronic products, while keeping the small distributed electrical parameters of the contacts to the ground.

The invention discloses a lateral light incidence type PIN photoelectric detector chip and a manufacturing method thereof. The PIN photoelectric detector chip comprises a substrate, a buffer layer, an absorption layer, a transition layer, a top layer, a contact layer, composite passivation layers, a first protection layer, a negative electrode, a positive electrode, a doped active region and an antireflection film, wherein the substrate is provided with a light incidence surface; the antireflection film is formed on the light incidence surface; an inverted V-shaped corrosion groove is formed in the bottom of the substrate, opposite to the doped active region, and is provided with a first side wall and a second side wall; the first side wall and the bottom surface of the substrate form an angle of 45 degrees; the first protection layer is a polyimide protection layer with low dielectric constant; the contact layer, the top layer, the transition layer and the composite passivation layer at the absorption layer form a P-type table surface; the composite passivation layer at the buffer layer forms an N-type table surface; both the P-type table surface and the N-type table surface are concentric with the doped active region.

The invention relates to a measuring circuit for moisture content and mineralization degree based on a plug-in impedance sensor. The measuring circuit is used for measuring moisture content and mineralization degree in an oil-water two-phase flow pipeline. The measuring circuit comprises an impedance sensor, a signal processing unit, a demodulation unit and a calculating unit; the impedance sensorcomprises an exciting measuring electrode and two protecting electrodes; the exciting measuring electrode is simultaneously served as an exciting electrode and a measuring electrode; the protecting electrodes are fixed above and under the impedance sensor; the signal processing unit comprises a front-end amplifier, a coaxial cable, an alternating current signal generator and a differential amplifier; a negative input end of the front-end amplifier is connected with the exciting measuring electrode in the impedance sensor through a coaxial cable signal wire; a positive input end of the front-end amplifier is connected with the alternating current signal generator and meanwhile is connected with the two protecting electrodes in the impedance sensor, a shielding layer of the coaxial cable and the negative input end of the differential amplifier; a standard resistor is connected with the negative input end and output end of the front-end amplifier; the output end of the front-end amplifier is connected with the positive input end of the differential amplifier.

The invention relates to a high-power self-cooled thyristor valve and a vehicle for assembling the same. The invention is characterized in that: a single-phase thyristor valve body comprises two thyristor valve string, and insulating tension rods, flanges, radiating fins, high-potential trigger plates, energy-taking magnetic rings, high-voltage energy-transmitting cables and a plurality of retaining nuts which are symmetrically distributed; every two thyristors are in positive and negative parallel connection with each other through flexible cables on the radiating fins to form a thyristor valve unit; a plurality of thyristor valve units form a thyristor valve string through parallel connection and upright stacking; radiating fins are pressed between each layer of thyristor valve units atintervals; the two thyristor valve strings form a single-phase thyristor valve through positive and negative parallel connection; both ends of the insulating tension rods are respectively fastened between an upper flange and a lower flange through the retaining nuts; the high-voltage energy-transmitting cables are connected to the inside of the thyristor valve body through the energy-taking magnetic rings of the high-potential trigger plates; the single-phase thyristor valve body inputs and outputs current through two moving contacts; the two moving contacts and the thyristor valve body are fixed together through copper bars which are fixed on the upper end and the lower end of the insulating tension rods through the flanges; and annealed copper sheets which are communicated with the radiating fins are arranged on the copper bars.