Abstract: A method and apparatus are provided for the electrochemical treatment of an aqueous solution in an electrolytic cell. Output solution having a predetermined level of available free chlorine is produced by applying a substantially constant current across the cell between an anode and a cathode while passing a substantially constant throughput of chloride ions through the cell.

Abstract: The present invention includes an apparatus and method for providing optimal uniformity of deposition during an electroplating process. The system may include an agitating device which is configured to provide agitation to the anode basket, a bias current distributed over a control grid (e.g., titanium mesh) which is disposed between the anode and cathode, wherein the control grid is configured to substantially reduce the variation in the electric field across the cathode, a cathode which includes a backplate having a contact ring wherein the contact ring includes a device configured to increase the pressure of the contact ring against the backplate and/or a cathode mounted on a lead screw for providing axial movement of the cathode along an axis normal to the anode.

Abstract: A method and apparatus for electro-chemically depositing a metal onto a substrate. The apparatus generally includes a head assembly having a cathode and a wafer holder disposed above the cathode. The apparatus further includes a process kit disposed below the head assembly, the process kit including an electrolyte container configured to receive and maintain a fluid electrolyte therein, and an anode disposed in the electrolyte container. The apparatus further includes a power supply in electrical communication with the cathode and the anode, the power supply being configured to provide a varying amplitude electrical signal to the anode and cathode.

Abstract: Disclosed are methods and systems for generating hydrogen gas at pressures high enough to fill a hydrogen storage cylinder for stationary and transportation applications. The hydrogen output of an electrochemical hydrogen gas generating device is integrated with an electrochemical hydrogen compressor operating in a high-differential-pressure mode. The compressor brings the hydrogen produced by the gas generating device to the high pressure required to fill the storage cylinder.

Abstract: The flow of electrolyte and/or of ions is controlled by a diffuser element provided in a plating reactor, wherein, in one embodiment, the diffuser element comprises a mechanical adjustment mechanism to adjust the effective size of passages of the diffuser element. In another embodiment, the diffuser element comprises at least two patterns of passages that are movable relatively to each other so as to adjust an overlap and thus an effective size of the corresponding passages. Moreover, the path of ions within the plating reactor may be controlled by an electromagnetically driven diffuser element so that a required thickness profile on the workpiece surface may be obtained.

Abstract: An electroplating current supply system includes a power supply unit for supplying an object to be plated (4) with an electroplating current whose polarity is inverted at predetermined intervals. The power supply unit includes a first DC power supply (3A) supplying a positive current and a second power supply (3B) supplying a negative current. The system includes further a processing unit (58) for controlling the ratio in magnitude and duration of the positive current (I2) to the negative current (I1) supplied to the object so as to plate the object with a uniform coating.

Abstract: A plating method and apparatus for a substrate fills a metal, e.g., copper, into a fine interconnection pattern formed in a semiconductor substrate. The apparatus has a substrate holding portion 36 horizontally holding and rotating a substrate with its surface to be plated facing upward. A seal material 90 contacts a peripheral edge portion of the surface, sealing the portion in a watertight manner. A cathode electrode 88 passes an electric current upon contact with the substrate. A cathode portion 38 rotates integrally with the substrate holding portion 36. An electrode arm portion 30 is above the cathode portion 38 and movable horizontally and vertically and has an anode 98 face-down. Plating liquid is poured into a space between the surface to be plated and the anode 98 brought close to the surface to be plated. Thus, plating treatment and treatments incidental thereto can be performed by a single unit.

Abstract: An apparatus and method for processing microelectronic workpieces. The apparatus can include a housing at least partially enclosing a process environment, with a first processing chamber and a second processing chamber positioned within the housing. The first processing chamber can have a first electrically powered device, such as a first anode and/or a first cathode, and the second processing chamber can have a second electrically powered device, such as a second anode and/or a second cathode. A first power supply is electrically coupled to the first processing chamber to provide electrical power to at least one of a first anode and a first cathode, and a second power supply is electrically coupled to the second processing chamber to provide electrical power to at least one of the second anode and the second cathode.

Abstract: A cathode current control system employing a current thief for use in electroplating a wafer is set forth. The current thief comprises a plurality of conductive segments disposed to substantially surround a peripheral region of the wafer. A first plurality of resistance devices are used, each associated with a respective one of the plurality of conductive segments. The resistance devices are used to regulate current through the respective conductive finger during electroplating of the wafer. Various constructions are used for the current thief and further conductive elements, such as fingers, may also be employed in the system. As with the conductive segments, current through the fingers may also be individually controlled. In accordance with one embodiment of the overall system, selection of the resistance of each respective resistance devices is automatically controlled in accordance with predetermined programming.

Abstract: The present invention is directed to a new water treatment device comprising an electrolytic tank to put water in, an electrode provided in the electrolytic tank, a water treating path for pouring water in a pool and returning to the pool the water in the electrolytic tank, a residual chlorine sensor for measuring the residual chlorine concentration of water, and control means for controlling the energization of the electrode on the basis of the measured value by the residual chlorine sensor, and capable of simply and efficiently sterilizing water stored in pools of various sizes from a swimming pool to a home bathtub.

Abstract: The object of the invention is to provide a method and apparatus for treating membrane-containing material with electrical fields, in vitro, and with an added treating substance. With the method, a plurality of electrodes are arrayed around the material to be treated and are connected to outputs of an electrode selection apparatus. Inputs of the electrode selection apparatus are connected to outputs of a pulse sequence generator. A treating substance is added to the membrane-containing material. Electrical pulses are applied to the electrode selection apparatus and are routed through the electrode selection apparatus in a predetermined, computer-controlled sequence to selected electrodes in the array of electrodes, whereby the membrane-containing material is treated with the added treating substance and with electrical fields. The routing of applied pulses through the electrode selection apparatus to selected electrodes can be done in an enormous number of ways.

Abstract: A system is provided for removing dissolved metals from industrial wastewater by electrocoagulation. The system includes an electrocoagulation reactor with a DC power supply having an insulation support enclosure with positive and negative electrode plates disposed thereon. The electrode plates are insulated for each other but remain in direct contact with the wastewater as it flows between the electrodes. The DC power supply induces opposite charges on alternate electrodes thereby generating an electric field between adjacent electrodes to cause the electrodes to ionize and go into solution for interaction with the contaminants in the wastewater as it flows through the reactor. The reactor is housed in a pressure vessel container so the exterior pressure on the reactor is higher than its internal pressure preventing leakage of fluids and oxygen and hydrogen gases produced in the reactor by decomposition of water.

Abstract: In order to provide an image creating apparatus which is driven at a high speed by a low voltage and realizes high contrast, the image creating apparatus of the present invention applies a voltage selectively to surfaces of arranged plural polymeric electrolyte films and generate a potential difference between both surfaces of the polymeric electrolyte films to which the voltage is applied to deform the polymeric electrolyte films. This image creating apparatus can provide an optical shutter of an image recording apparatus and a reflection or transmitting type image display device.

Abstract: A system is for supplying a generator with hydrogen, in particular a generator of a power generating plant. The system offers a high level of safety while at the same time making handling easy. The system includes a closed system cycle for carrying water and/or gas and a hydrogen feed line, branching off from the system cycle, for the generator. The system cycle includes an electrolysis unit designed as a membrane electrolyzer.

Abstract: A device and method for removal of minerals from a supply of liquid such as water. The device includes a tank with an inner surface functioning as a first electrode, at least one inlet for liquid and at least one outlet to a system requiring liquid arranged such that entry and exit of liquid create a cyclonic flow, at least one second electrode within the tank placed so that the cyclonic flow of liquid passes between the two electrodes, and a mechanism for creating an electric current flowing between the two electrodes. The method includes the steps of causing a liquid to circulate cyclonically within a tank, applying an electric current to the circulating liquid so that minerals within the liquid precipitate on an inner surface of the tank, and reversing a polarity of the electric current in order to loosen the precipitated minerals from the inner surface of the tank.

Abstract: A method of treating a sample in contact with an electrolyte is disclosed. A non-sinusoidal alternating current (AC) comprising repeated waveform cycles is passed between the sample and the electrolyte. A number of advantageous forms of non-sinusoidal AC are disclosed. The method may, for example, be used in cleaning surface oxide layers from stainless steel.

Abstract: A method of immersing a substrate into electrolyte solution for electroplating, the method comprising connecting an electric source between an anode immersed in the electrolyte solution and a seed layer formed on the substrate. A first voltage level of the seed layer is biased to be equal to, or more positive than, a second voltage level of the anode. The substrate is then immersed into the electrolyte solution.

Abstract: The object of the invention is to provide a method and apparatus for treating membrane-containing material with electrical fields, in vitro, and with an added treating substance. With the method, a plurality of electrodes are arrayed around the material to be treated and are connected to outputs of an electrode selection apparatus. Inputs of the electrode selection apparatus are connected to outputs of a pulse sequence generator. A treating substance is added to the membrane-containing material. Electrical pulses are applied to the electrode selection apparatus and are routed through the electrode selection apparatus in a predetermined, computer-controlled sequence to selected electrodes in the array of electrodes, whereby the membrane-containing material is treated with the added treating substance and with electrical fields. The routing of applied pulses through the electrode selection apparatus to selected electrodes can be done in an enormous number of ways.

Abstract: Various systems and methods for protecting electrowinning anodes having electrocatalytically active coatings in a bank of electrolytic cells from being damaged by reverse currents. In the first embodiment, one or more auxiliary power sources are provided that, when triggered by one or more predetermined conditions being met, keep the bank of electrolytic cells in an electrical state that is relatively harmless to the anodes having electrocatalytically active coatings. In a second embodiment, the invention is directed to a method of maintaining the polarization of anodes in an electrowinning cell positive of the cathodes (i.e. in a potential region where the anode coating is not susceptible to significant damage). In a final embodiment, the invention is directed to various methods for the installation of replacement anodes and maintenance of electrowinning cells.

Abstract: A mineral ionizing device (10) consisting of a container (20) filled with water and containing a solid-mineral, cylindrical first electrode (50), a second electrode (58) coaxially located within the first electrode (50), a vibration unit (100) which produces a vibration within the container (20), a set of protrusions (64) located on the surface of the second electrode (58) and a periodic current reversing unit (84) which applies a d-c current across the first and second electrodes (50,58). The combination of the vibration unit (100), the protrusions (64) and the current reversing unit (84) aids in releasing gaseous bubbles which form on the surface of the second electrode (58). The application of the d-c current causes the mineral in the first electrode (50) to release mineral ions into the water which results in the production of very clean mineral water.

Abstract: A method of immersing a substrate into electrolyte solution for electroplating, the method comprising connecting an electric source between an anode immersed in the electrolyte solution and a seed layer formed on the substrate. A first voltage level of the seed layer is biased to be equal to, or more positive than, a second voltage level of the anode. The substrate is then immersed into the electrolyte solution.

Abstract: The invention relates to a method for controlling the recovery of a metal, such as silver, from a solution flowing through an electrolytic cell. A constant current is applied between the anode and cathode of the cell and the rate of change of the voltage monitored, the information obtained from the monitored change of voltage being used to control the rate of recovery of the metal.

Abstract: A method for on-line removal of cathode depositions during electrochemical process. The process control means (30) are arranged to alternate the unipolar machining voltage pulses U1 with the voltage pulses of opposite polarity U2 to the work piece (2) and the cathode (3). The process control means comprise an arrangement to determine the amount of cathode depositions on-line based on the operational parameter. Only in case the operational parameter exceeds the allowable level, the process control means (30) alternate the unipolar machining voltage pulses U1 with the voltage pulses of opposite polarity U2. In this case the cathode wear is minimized.

Abstract: For an electromechanical machining of a work piece there is an optimal pulse duration for the machining pulses corresponding to the maximum copying accuracy. Such an optimal pulse duration corresponds to a certain value of the gap. By alternating the machining pulses with measurement pulses it is possible to obtain an accurate information about the gap dimensions on-line during the electrochemical machining process. The process control means (20) are used to automate the electromechanical machining, while keeping it in the optimal mode. For this purpose the process control means (20) comprise the pulse control unit (26) to establish the pulse duration of the voltage pulses to be applied across the gap (4).

Abstract: An apparatus for rotary cathode electroplating having a head assembly, a substrate/thief assembly having a thieving ring which includes a number of individually chargeable segments, and a secondary induction assembly including a secondary core and a secondary winding. A motor drives the substrate/thief assembly to rotate relative to the head assembly. A controller directs electrical charge to each of the individually chargeable segments of the thieving ring. An electrical storage device stores electrical energy which is to be supplied to the controller. A charging apparatus induces a magnetic flux which induces an alternating current in the secondary winding of the secondary induction assembly. A converter converts the induced alternating current to direct current, which is then stored on the electrical storage device.

Abstract: An electroplating apparatus includes a reactor vessel having a segmented anode array positioned therein for effecting electroplating of an associated workpiece such as a semiconductor wafer. The anode array includes a plurality of ring-like anode segments which are preferably positioned in concentric, coplanar relationship with each other. The anode segments can be independently operated to create varying electrical potentials with the associated workpiece to promote uniform deposition of electroplated metal on the surface of the workpiece.

Abstract: A single delivery channel is formed by, and between, inner wall 2 and baffle 3. Electrolyte 5 is pumped up the interior of channel 1 and is directed onto substrate 4 being a cathode maintained at −10 volts. The upper part of the inner wall 2 of channel 1 forms the anode such that electrote is forced between the substrate and the upper horizontal surface of the anode 6. A second baffle 7 is provided in order to assist in collecting and removing electrolyte 5 after impingement with substrate 4, possible for re-use. Contact between the electrolyte 5 and substrate 4 is optimised by providing the electrolyte with a swirling motion as it passes up channel 1. Anode 6 is a solid conducting bar 10, alternatively it is formed of solid rods 11 nor tubes 12.

Abstract: The invention concerns a motorized device for adjusting the interelectrodic gap in mercury cathode electrolysis cells, mainly consisting of a frame, to which a number of anodes are suspended, movable in the vertical direction by means of a single jackscrew driven by a gear motor acting on double levers. The jackscrew with the motor and the lever system are fixed to a main frame, supported on the cell bottom by means of supports positioned on adjustable columns, while the above mentioned movable frame (also called sub-frame) carrying the anodes, is connected to the lever arms by means of four hinged supports. The shifting of the movable frame and, consequently, of the anodes can be controlled by a centralized and computerized system (which is not part of the invention) as a function of voltage and current variation measurements.

Abstract: A system and component, as well as a method of using them, according to disclosed embodiments of the present invention, relate to the use of at least one electrode positioned in a flowing fluid having entrained unwanted substances. The electrode is energized electrically to provide current flow in the fluid to produce a sufficient amount of electrical power in the flowing fluid to cause substances in the fluid to be disturbed for effectively treating the fluid.

Abstract: The manufacturing apparatus for producing alkaline ionized water and acidic water by electrolysis of water has an electrolytic bath including a cathode cell, an intermediate cell, and an anode cell, separated by diaphragms; an electrolysis solution bath connected to the intermediate cell via an electrolysis solution circulating line and an electrolysis solution circulating pump; a circulation container bath for alkaline ionized water connected to the cathode cell via an alkaline ionized water circulating line and an alkaline ionized water circulating pump; a supplying line for raw material water for producing acidic water connected to an inlet of the anode cell; a withdrawing line for acidic water connected to an outlet of the anode cell; a supplying system for raw material water for making the alkaline ionized water connected to the circulation container bath and a withdrawing line with a water collecting device for withdrawing alkaline ionized water.

Abstract: The present invention relates to a substrate plating apparatus for plating a substrate in a plating bath containing plating solution. An insoluble anode is disposed in the plating bath opposite the substrate. The substrate plating apparatus comprises a circulating vessel or dummy vessel provided separate from the plating bath, with a soluble anode and a cathode disposed in the circulating vessel or dummy vessel. An anion exchange film or selective cation exchange film is disposed between the anode and cathode and isolates the same, wherein metal ions are generated in the circulating vessel or dummy vessel by flowing current between the soluble anode and the cathode therein, and the generated metal ions are supplied to the plating bath.

Abstract: In an electrolytic gas converter for converting atmospheric moisture into ozone gas, oxygen gas or hydrogen gas, the electrolytic gas converter is provided with a unit for making control so that an electric current is supplied to the electrochemical device conjunctive body during a predetermined period of time after the start of the operation of gas conversion, the electric current being larger than that after the predetermined period of time passes. In addition, the control unit controls the current to flow periodically. Further, the electrolytic gas converter is provided with a unit for making control so that a predetermined constant current is supplied to the electrochemical device conjunctive body after the predetermined period of time passes since the operation of gas conversion is started.

Abstract: A method, system and structure for a pin grid or pad grid array structure includes a plurality of pins connected to an electronic structure, a power plane within the electronic structure electrically connected to power pins, a ground plane within the electronic structure, and fuse portions electrically connecting the ground plane to ground pins and signal pins. The power plane and the ground plane create a charge in the pins during electroplating of the pins. The fuse portions disconnecting the signal pins from the ground plane after the electroplating.

Abstract: A hydrogen replenishment system for providing hydrogen to a hydrogen-receiving apparatus, the system comprising (i) an electrolytic cell for providing source hydrogen; (ii) a compressor means for providing outlet hydrogen at an outlet pressure; (iii) means for feeding the source hydrogen to the compressor means; (iv) means for feeding the outlet hydrogen to the hydrogen-receiving apparatus; (v) central processing unit means for controlling the cell and the compressor; and (vi) user activation means for operably activating the central processing unit means. The invention provides a practical user interface in the treatment of data provided, computed, measured and stored, to offer a convenient, essentially self-contained, hydrogen fuel replenishment system for vehicles based on water electrolysis. The apparatus has virtually no stored hydrogen and provides pressurized hydrogen on the demand of a user.

Abstract: The present invention relates to a device that supplies electricity to a substrate. In one embodiment, the device includes multiple contacts, a current sensor, and a current regulator. The current sensor is attached to each of the plurality of contacts to sense their electric current. A current regulator controls current applied to each of the multiple contacts in response to the current sensor. In another embodiment, a compliant ridge is formed about the periphery of each contact to seal the contact from undesired chemicals.

Abstract: An electroplating current supply system includes a power supply unit for supplying an object to be plated (4) with an electroplating current whose polarity is inverted at predetermined intervals. The power supply unit includes a first DC power supply (3A) supplying a positive current and a second power supply (3B) supplying a negative current. The system includes further a processing unit (58) for controlling the ratio in magnitude and duration of the positive current (I2) to the negative current (I1) supplied to the object so as to plate the object with a uniform coating.

Abstract: Methods for electroplating metal can include passing an electrical current through a conductive surface and an electroplating solution adjacent the conductive surface. An electroplating voltage for the conductive surface and the electroplating solution can be determined based on the electrical current through the conductive surface and the electroplating solution adjacent the conductive surface. The determined electroplating voltage can then be maintained while electroplating the metal from the electroplating solution on the conductive surface. Related systems are also discussed.

Abstract: The method of this invention for producing electrolyzed water containing ozone employs an apparatus for producing electrolyzed water from a liquid. The apparatus has two plate electrodes facing each other, a D.C. power source for applying a D.C. voltage across the electrodes and a control circuit for changing a polarity of the electrodes alternately.

Abstract: An innovative application for the purification of potable water for at source use, specifically focusing on disinfection of water using an electrolytic process. The process uses the discharge of electrical energy between electrodes to create reactive species in water, which then react with pathogens to provide the disinfected water. The invention includes a novel and unique controller system to assure that the reaction process and reactor will function reliably to produce treated water. The controller may respond to flow or pressure conditions, reactor status, treatment effectiveness, or other parameters monitored by various sensing devices. Specific examples of the application are for use in beverage dispensing machines, ice-making machines, tap water purification for domestic and commercial potable water use, water dispenser machines that use tap water, and similar uses for potable water.

Abstract: A water chlorinator comprises a housing having in-line inlet and outlet openings and a removable cover. The cover supports two electrode terminals which are spaced apart and have corresponding rods extending therefrom through concentric anode and cathode discs. Alternate discs are electrically connected to each rod. The power supply is a DC supply which includes an input bridge connected to a buck convertor and an output relay arranged to switch the output from the convertor to the electrodes of the chlorinator.

Abstract: An ozonized water generating device in which an inside of a casing is defined by a solid electrolyte film into an anode chamber and a cathode chamber. An anode electrode made of noble metal having an ozone generating catalyst function is arranged to be impressed against the solid electrolyte film at the anode chamber, a cathode electrode is arranged to be impressed against the solid electrolyte film at the cathode chamber, respectively. Each of the anode chamber and the cathode chamber is provided with a raw water flow inlet port and an electrolyzed water flow outlet port, and a DC voltage is applied between the anode electrode and the cathode electrode, wherein either one of or both the anode electrode and the cathode electrode are arranged in such a way that they can be impressed against and separated from the solid electrolyte film by a movable driving piece.

Abstract: A device as described for the generation of high purity carbon dioxide (CO2) and hydrogen (H2) by electrochemical decomposition of aqueous solutions of liquid and solid organic acids. A d.c. power source is used to apply a preselected current to an electrochemical cell, consisting of an ion permeable membrane and two electrodes. The generation rate of CO2 and H2 is continuous and proportional to the applied current; it can be stopped instantaneously by interrupting the current. Small Battery operated generators can produce propellant CO2 and H2 to deliver fluids from containers. Other uses include the creation of anaerobic environments in incubation chambers.

Abstract: A method for dehydrating a porous material using electro-osmosis, includes applying a pattern of D.C. voltage pulses to an anode system embedded in the porous material, wherein the anode system is electrically interactive with a cathode structure embedded in earth, and wherein the pattern of D.C. voltage pulses, has a pulse period T in a range from about 3 to about 60 seconds, and each pulse period T includes a positive pulse duration of T+ from about 0.7T to about 0.97 T, a negative pulse duration of T− from about 0.01T to about 0.05T, and a neutral pulse duration of Tp from about 0.02T to about 0.25T. In another embodiment, each pulse period includes two or more positive pulses separated by at least one of either a negative pulse or a neutral pulse, with the positive pulse duration being the combined duration of the two positive pulses.

Abstract: The invention relates generally to ceramic oxygen generating modules, and more particularly, to an apparatus and method for controlling a duty cycle for each of a plurality of ceramic oxygen generating modules in a modular ceramic oxygen generating system.

Abstract: A water electrolytic system includes a water electrolyzer, a photovoltaic generator which is a power source for the water electrolyzer, and a DC/DC converter adapted to convert the maximum output from the photovoltaic generator into a current and a voltage corresponding to an IV characteristic of the water electrolyzer by converting current and voltage for a portion of such maximum output, and to input the converted current and voltage to the water electrolyzer. With the water electrolytic system, even when an optimal point of operation of the photovoltaic generator, i.e., the maximum output from the photovoltaic generator has been varied, the efficient operation of the water electrolytic system can be carried out utilizing such maximum output.

Abstract: The electrodes have jet openings which jet the electrolyte to the steel strip, that is to say, the electrode is integrated with the nozzle which jets an electrolyte.

Abstract: A compositionally modulated material electroplated film is deposited by using at least two source metal anodes in an electroplating apparatus, and changing at least one contact area between an anode an electrolyte. In order to obtain sharp boundaries between successive layers of the film, voltage can be switched from an electroplating substrate to a dummy electrode immediately before the contact area is changed, in order to allow the electrolyte to equilibrate at a new set of solute concentrations, before electroplating on the substrate is recommenced.

Abstract: A compositionally modulated material electroplated film is deposited by using at least two source metal anodes in an electroplating apparatus, and changing at least one power setting of an electroplating power supply. In order to obtain sharp boundaries between successive layers of the film, voltage can be switched from an electroplating substrate to a dummy electrode immediately before the power setting is changed, in order to allow the electrolyte to equilibrate at a new set of solute concentrations, before electroplating on the substrate is recommenced.

Abstract: An electrolytic method is disclosed by which occlusion of hydrogen or sticking of atoms or molecules in plating and so forth is not disturbed by electronic magnetic force produced by main electric current and ion current flowing from the positive electrode to the negative electrode through electrolyte. An electric circuit separate from a positive electrode and a negative electrode is provided between the positive electrode and the negative electrode, and electric current of a direction opposite to that of main electric current and ion current flowing in the electrolyte from the positive electrode to the negative electrode is supplied to the electric circuit to produce an opposite magnetic field which cancels a magnetic field produced by the main electric current and the ion current flowing in the electrolyte.

Abstract: A cathode current control system employing a current thief for use in electroplating a wafer is set forth. The current thief comprises a plurality of conductive segments disposed to substantially surround a peripheral region of the wafer. A first plurality of resistance devices are used, each associated with a respective one of the plurality of conductive segments. The resistance devices are used to regulate current through the respective conductive finger during electroplating of the wafer. Various constructions are used for the current thief and further conductive elements, such as fingers, may also be employed in the system. As with the conductive segments, current through the fingers may also be individually controlled. In accordance with one embodiment of the overall system, selection of the resistance of each respective resistance devices is automatically controlled in accordance with predetermined programming.