US3852665A - Apparatus for testing potentiometers - Google Patents

Apparatus for testing potentiometers Download PDF

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Publication number
US3852665A
US3852665A US00332008A US33200873A US3852665A US 3852665 A US3852665 A US 3852665A US 00332008 A US00332008 A US 00332008A US 33200873 A US33200873 A US 33200873A US 3852665 A US3852665 A US 3852665A
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Prior art keywords
potentiometer
carrier
spindle
potentiometers
driving means
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M Bothner
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Amphenol Corp
Bunker Ramo Corp
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Bunker Ramo Corp
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Assigned to AMPHENOL CORPORATION, A CORP. OF DE reassignment AMPHENOL CORPORATION, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: ALLIED CORPORATION, A CORP. OF NY
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
    • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
    • B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
    • B07C5/34—Sorting according to other particular properties
    • B07C5/344—Sorting according to other particular properties according to electric or electromagnetic properties
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/2832—Specific tests of electronic circuits not provided for elsewhere
    • G01R31/2836—Fault-finding or characterising

Definitions

  • Arbuckle 1 An apparatus for testing potentiometers utilizing an endless carrier which moves past a plurality of devices positioned at stations along the carrier.
  • a feeder device inserts potentiometers into potentiometer supports on the carrier, an adjusting device moves the slider of the inserted potentiometer to a base position, and an evaluation device moves the slider while simultaneously measuring test parameters of the inserted potentiometer,
  • an ejection device is included which ejects tested potentiometers into selected receptacles.
  • G.,l3c A APPARATUS FOR TESTING POTENTIOMETERS BACKGROUND OF THE INVENTION 1.
  • the present invention relates to an apparatus for testing potentiometers, utilizing an. endless carrier having support devices for carrying potentiometers to various test stations of a measuring system.
  • potentiometers are usually tested for certain parameters such as continuity, total resistance, and contact noise before they are released for sale.
  • the time required for testing must be short so that the cost of testing does not significantly contribute to the total cost of each potentiometer.
  • the production cost of miniature potentiometers or trimmer potentiometers is very low in modern production technologies, and the cost of testing the potentiometers can have a significant influence on the total cost of the potentiometers. Therefore, a highly automated testing procedure is required to economically test such potentiometers. I
  • a known system comprises a working table with a rotating disk and a testcabinet connected to the table via cables.
  • the rotating disk is provided with twelve holders on its periphery, so that twelve potentiometers can eters which pass through all test stations without rejection are released for sale. Boththe mechanical equipment and the expensive, so that the cost of production testing utilizing such system is high. Further, the system is prone to .malfunctions because of complexity.
  • An object of this invention is to create a reliable and economicaltesting system which can test potentiomelectronic I instruments requiredin such prior art system are very According to the invention, this object is reached by providing an apparatus having an endless carrier which is movable past a plurality of devices positioned at stations adjacent the carrier.
  • the endless carrier has a plurality of potentiometer supports which hold the potentiometers.
  • the devices stationed adjacent the endless carrier operate upon the potentiometers and include: a feeder device for inserting potentiometers into the supports, an adjusting device for moving the slider of the potentiometers to a base position, and an evaluation device for moving the slider through the entire resistance range while simultaneously measuring test parameters of the potentiometer.
  • the mechanical design and electronic circuitry of the potentiometer test apparatus of this invention is very simple, since several parameters are simultaneously tested in the evaluation device. For example, continuity, contact noise, and total resistance of each potentiometer can be tested inthe evaluation device. Since all the required measurements are made in the evaluation station, a decision can be made immediately after testing in a single station to accept or reject the potentiometer.
  • the evaluation device is conveniently provided with a cathode-ray tube and a constant-current source which areconnected to the potentiometer in the evaluation station.
  • Potentiometers generally'have three ter-- minal contacts and are referred to hereinas a first terminal Contact, a slider contact, and a second terminal contact.
  • the output terminals of the constant-current source are connected between fthe first terminal contact andthe slider contact of the potentiometer,- while the second terminal contact of the potentiometer and the slider contact are connected to the vertical input of the cathode-ray tube.
  • Potentiometers are frequently provided with'a slip clutch to prevent destruction of the slider when rotational motion causes the slider to exceed the end positions.
  • the slider is frequently'driven by a spindle which engages a member moving the slider. When the slider hits a stop provided at the ends of the resistor body, the
  • the member is of this type canhave a U-shaped brace which enters into the thread grooves of the spindle and is inserted in a plastic block abutting the spindle.
  • this block is kept in a certain position while the spindle rotates, the block is deformed by the increased force acting upon the spindle, and the brace jumps from one thread groove on the spindle to the next groove.
  • a known slip clutch provides for a coupling between the slider and a disk, with the disk having radial elevations and grooves engaging the spindle. When a certain driving force is exceeded, the elevations and grooves disengage the spindle until the spindle is moved in an opposite direction.
  • trimmer potentiometers are usually highly sensitive to mechanical loads, and the slip clutches of trimmer potentiometers are particularly sensitive to mechanical loads.
  • the slipclutch action can be repeated only a few times without serious damage to the trimmer potentiometer.
  • Standards have been proposed requiring that the slip clutch of a trimmer be able to jump (or idle) at least cycles over thread grooves without damage. It is therefore desirable to keep the slip clutch out of operation during the testing procedure to avoid quality losses in trimmer potentiometers.
  • the risk of actuating the slip clutch is particularly great when the slider is brought into a certain basic position in the adjustment station of the test unit. For practical considerations, the basic position is selected so that the slider bears against one end of the resistor body. However, this is usually the range in which the slip clutch begins to become effective when the slider is rotated.
  • lt is advantageous to adjust the potentiometer to a certain basic position by moving the potentiometer slider toward one of the terminals until the ratio of the total resistance between the terminals to the resistance between the slider and the terminal selected has reached a certain value.
  • this value must be below the point at which the slip clutch is normally actuated so that the basic position can be reached without actuating the slip clutch.
  • the apparatus of this invention can be used wherever the slider of a potentiometer or trimmer potentiometer must be adjusted to a certain resistance value.
  • the end terminal contacts of the potentiometer to be tested are connected to a constantvoltage source, and the voltage between the potentiometer slider contact and one of the terminal contacts is compared with a reference voltage by means of a differential amplifier.
  • a circuit of this type is simple, can be produced at low cost, and operates with high accuracy. Moreover, the desired voltage ratio can be easily adjusted.
  • an ejection station is provided after the evaluation station.
  • the tested potentiometers are released and sorted.
  • the tested potentiometers could be ejected in the evaluation station.
  • the evaluation station is the station in which the potentiometers remain for an extended period of time, it is more advantageous to provide a separate station and ejection device for potentiometer ejection.
  • the cycle time (the time the potentiometer is in the test unit) is then reduced.
  • the sorting mechanism takes care of the transport of the released potentiometers to a collecting receptacle when a corresponding key is depressed.
  • two such collecting receptacles are used, one for receiving the accepted potentiometers and the other for receiving potentiometers having defects of some kind.
  • each receptacle When collecting receptacles are used, it is desirable to provide each receptacle with a counter for counting the potentiometers entering into the particular receptacle.
  • the carrier may be provided in the form of a wheel. This simplifies the design'of the testing unit.
  • the wheel of the carrier comprises a square base which is mounted on a shaft and carries exchangeable potentiometer supports on its radial faces.
  • the test set can be rapidly adjusted from one type of potentiometer to be tested to another type with different dimensions by inserting an appropriate potentiometer support.
  • the potentiometer support comprises a clamping device.
  • the clamp is of a very simple design, and the potentiometer to be tested is simply pushed into the clamp at the feeder station.
  • the carrier wheel is provided with a self-locking Geneva drive (for converting continuous motor drive to station-cycle operation).
  • each potentiometer support is conveniently provided with a group of three contacts which are connected to the three terminal contacts of the potentiometer inserted into the support. Contact isestablished while the potentiometer is mechanically supported, and no additional operation must be performed 'in order to establish electric contact. Each contact group moves from one test station to the next as the carrier rotates, whereby each contact group is connected to the corresponding measuring equipment of the test station.
  • a switching-means may be provided on the shaft of the carrier wheel. This switching means establishes a connection between the contacts on the carrier wheel and the measuring equipment as required by position of the contacts in each station.
  • a certain switch combination is selected ineach position of the shaftcorresponding' to the potentiometers to be tested at each particular test station.
  • the switch combination ensures that the measuring equipment terminals pertaining to a certain test station are connected with the contact groups located at the particular test stations in which measurements are taken.
  • a switching device of this type can be easily built and is very reliable in its operation.
  • Such a switching means may be built from magnets and reed contacts. Either the magnets or the reed contacts are mounted on a disk which is connected to the shaft driving the feed wheel. Respective reed contacts or magnets are fixedly mounted on a stationary coaxial cylinder surface. The magnets and reed contacts are arranged so that in each position of the shaft, a certain combination of reed contacts is closed.
  • a switching means of this type is very reliable in its operation and can be produced at low cost.
  • a feed duct may be provided at the feeder station.
  • One potentiometer at a time can be transferred by means of a transfer device from the feed duct to a potentiometer'support on the feed wheel.
  • the feeder device may be providedwith a spindle device whichacts upon'the potentiometer to be moved. This simplifies the design of the feeder device and ensures an accurately controllable transfer motion of the potentiometer.
  • the slider driving units in the adjustment and evaluation devices may be provided with limiting switches which interrupt the slider motion after a certain adjustable rotationof the driving units, or after a certain number of full rotations in a particular direction of motion.
  • the potentiometer slider may then be moved automatically over the full resistance range without need' for a manual interruption of the driving force or a manual reversal of the direction of rotation.
  • the limiting switches ensure that the slider, once it has been moved from a previously adjusted basic position, can approach the end points of the resistor'only to the extent where a mechanical overload cannot occur and the slip clutch is not actuated.
  • the shaft of the driving unit need not be rotated in order to return the limiting switches to their initial positions.
  • the potentiometer to be tested may be removed from the evaluation device when the potentiometer slider is not in the baseposition. In such instances, before anew potentiometer is introduced, the limiting slider of the potentiometers;
  • the limiting switch is conveniently provided with a rotatable disk which is rotated either directly by the driving shaft or via a reduction gear.
  • the disk can move between two positions of rotation which are determinedby the position of photoelectric transmission units.
  • a rotating disk which is rotated directly by the shaft of the driving unit is used only when the shaft of the driving unit has to perform a maximum of one rotation for rotating the potentiometer slider.
  • potentiometers having a circular resistor body with a slider in concentric position Such is the case with potentiometers having a circular resistor body with a slider in concentric position.
  • a reduction gear is inserted between the driving shaft and the rotating disk. In any event, the rotating disk must rotate less than 360 when the slider is moved over the entire resistance range.
  • a limiting switch comprising a rotating disk with photoelectric transmission units can be easily produced and ensures highly accurate measurements.
  • An electromagnetic clutch may be inserted between the rotating disk and the shaft of the driving unit, and the rotating disk may be biased by means of a spring so that the disk returns to its initial position when the clutch is released. In this way, the return of the rotating disk to its initial position can be easily initiated via an electric contact.
  • the photoelectric transmission unit may be adjustable to set the limiting positions of the rotating disk. Then the limiting switch can be adjusted to various types of potentiometers to be tested for which various angles or various numbers of full rotations are required.
  • One of the separate, but similar, driving units is conveniently used in each of the adjustment and evaluation devices.
  • a slider-actuating member mounted on the driver shaft and shiftable in the axialdirection.
  • the entire driving unit does not have to be moved in axial direction when the actuating member is disengaged and removed from the potentiometer.
  • a solenoid can be used to shift the actuating member against the force of a compression spring to facilitate electrical control of the advance of the actuating member in axial direction.
  • FIG. 1 is an overall view of the test apparatus of the invention
  • FIG. 2 is a front view of the carrier wheel, the feed duct, and the feeder device of the test apparatus of.
  • FIG. 1 A first figure.
  • FIG. 3 is a top view of the driving mechanism in the test apparatus
  • FIG. 4 is a cross section taken along line 4-4 of FIG. 3;
  • FIG. 5 isa cross section taken along line 5-5 of FIG.
  • FIG. 6 is a cross section of the carrier wheel
  • FIG. 7 is a side view of the. driving unit for driving the FIG. 8 is a top view of the driving unit of FIG. 7;
  • FIG. 9 is a cross section taken along line 99 of FIG. 8;
  • FIG. 10 is a cross section taken along line 1010 of FIG. 8;
  • FIG. 11 is a schematic diagram of the voltagecomparison circuit
  • FIG. 12 is a schematic diagram of the circuit for measuring the test parameters.
  • FIGS. 13a through 13e are typical oscilloscope test patterns.
  • FIG. I shows a work bench with a test apparatus of the invention.
  • the test apparatus is mounted on a rack in cabinet 1.
  • the apparatus comprises three units which can be mounted in racks.
  • the lowermost unit comprises the mechanical components 2 which feed the potentiometers to be tested to the various test stations.
  • the unit in the center comprises several subunits with the electronic control and test equipment 3.
  • the uppermost unit contains an oscilloscope 4.
  • Test cabinet 1 is placed on bench S in which a keyboard 6 is inserted.
  • Several collecting receptacles are mounted under the top of bench 5. These receptacles are filled with tested potentiometers.
  • a slot 8 is provided in bench underneath the ejection area of mechanical components 2 of the apparatus. The ejected potentiometers pass through slot 8 in the bench top into collecting receptacles 7.
  • Mechanical components 2 comprise: a carrier wheel 9 which acts as an endless carrier; a feed duct and a feeder device 11, both at a feeder station 12; and two driving units 13, which are offset 90 and are used' to drive the sliders of the potentiometers to be tested.
  • carrier wheel 9 comprises a square base 14 having four segment-shaped potentiometer supports 15 mounted on the periphery by means of two screws 16 and 16.
  • Each support 15 carries a clamp 17 which can be used to support a trimmer or potentiometer l8.
  • Clamp 17 consists of a clamping lever 22 which is moved around shaft 21 toward stop by means of a compression spring. That portion of clamping lever 22, which faces potentiometer 18, is rounded so that the potentiometer can be inserted into clamp 17 without need for actuating the clamping lever.
  • the clamping lever is provided with a bore through which a screw 23 passes which, in turn, is screwed into support 15. This screw can be used to adjust the minimum distance between clamping lever 22 and stop 20.
  • each support 15 is provided with three blade contacts 24.
  • a set of three blade contacts 24 is shown in FIG. 3.
  • Blade contacts 24 establish an electric connection to one of each of the terminal contacts 18' of the potentiometer.
  • leads 25 are connected to blade contacts 24.
  • Leads 25 are connected via a plug connector 26 mounted in holding device 15 to a IZ-terminal mercury transfer coupler 27 (shown in FIG. 3) for transferring the measuring currents from the rotating supports to the stationary electrical instruments.
  • the center of carrier wheel 9 is coupled to shaft 28 which is supported by two ball bearings 29 in front plate 2a of the housing.
  • a Geneva wheel 30 is mounted on the shaft in order to drive the shaft.
  • the Geneva wheel is driven by a motor 31 via a worm gear 32.
  • Motor 31 is of the disk-rotor type.
  • Feed station 12 consists of feed duct 10 and feeder device 11, and serves to introduce potentiometers 18 to be tested into supports 15 of carrier wheel 9. Details of feed station 12 are shown in FIGS. 2 and 3.
  • Feed duct 10 is in a generally vertical position and forms a tangent to carrier wheel 9. As shown in FIG. 3, the interior profile of feed duct 10 is such that potentiometers 18 can be introduced only when they are in a certain position.
  • feed duct 10 is provided with an opening 33 facing carrier wheel 9. Potentiometers are transported from opening 33 into holding device 15 of carrier wheel 9 by means of feeder device 11.
  • Feeder device 11 comprises two feed pins 34, which can move radially (with respect to carrier wheel 9) into feed duct 10 and engage the lowermost potentiometer in feed duct 10.
  • Feed pins 34 are mounted on a sliding member 35 which is provided with a thread and is set into reciprocating motion by a spindle 37 driven by a motor 36.
  • a limiting pin 38 which reciprocates between two stops 39 and 40 is mounted on sliding member 35 and extends perpendicular to the direction of motion of the sliding member.
  • Electric switch contacts attached to stops 39 and 40 form limiting switches for the motion of motor 36.
  • Motor 36 is conveniently coupled to a device which shuts off the motor once a torque exceeding a certain critical value is reached. Excessive torque could arise when a potentiometer to be tested jams while it is introduced in the test apparatus.
  • Two driving units 50 and 51 are mounted in two test stations in offset relationship and are used to rotate the sliders f0 potentiometers 18.
  • FIGS. 7 through 10 show details of the driving units.
  • FIG. 3 shows the support of one of the driving units.
  • Driving units 50 and 51 are designed for driving potentiometers having a spindle for moving the slider. In order to move the slider from one end of the resistor body to the other end, several spindle rotations are required.
  • the driving unit shown is provided with a driving motor 52 which is a disk-rotor motor like the driving motor of carrier wheel 9.
  • Driving motor 52 is coupled to one end of a shaft 53.
  • the other end of shaft 53 is carried in a sleeve 54 which in turn is carried within a second sleeve 56.
  • Sleeve 56 is driven from shaft 53 by a cross-pin 53'.
  • Shaft 53 is supported in bearings 55, and sleeve 56 in bearings 55'.
  • the intermediate sleeve 54 has axially elongated slots 57 through which the cross-pin 53' passes, so that the sleeve 54 is driven thereby in accordance with the rotation of shaft 53, but can slide longitudinally thereon, and inside of sleeve 56.
  • the inner end of the sleeve 54 is provided with a radial flange 58.
  • a compression spring 58 acts on one side of the flange, normally keeping the sleeve 54 in extended position.
  • a yoke 59 carrying ball bearings 60 is mounted on a rotary actuator magnet 61 (FIG. 7) with the bearings 60 engageable with flange 58, so that when the magnet 61 is energized, the flange 58 and sleeve 54 are retracted against the force exerted by spring 58'.
  • sleeve 54 The front end of sleeve 54 is provided with a driver head 54, carrying a screwdriver tip 54", formed so that it enters into the screw groove usually provided on a potentiometer with a spindle for moving the slider.
  • the tip 54" is removable (see FIG. 10) so that different types can be used as may be necessary for different forms or sizes of potentiometer spindles.
  • a worm gear 62 which can be used to drive a gear 63, mounted in the housing of the driving unit, is mounted in line with shaft 53.
  • Gear 63 is mounted on a shaft 64 which carries a rotatable disk 65.
  • Disk 65 is provided with a radial slot 66. As can be inferred from FIGS.
  • two photoelectric units 67 and 67 are mounted so that anincandescent lamp 68 is situated on one side of the disk and a photoelectric pickup 69 is situated on the other side of the disk. Light can shine upon photoelectric pickup 69 only when slot 66 or rotating disk 65 is situated adjacent photoelectric pickup 69.
  • One of the two photoelectric units 67 can be rotated around shaft 64 in order to adjust the angular distance between the two transmission devices.
  • Rotating disk 65 is not directly coupled to gear 63, but an electric clutch 70 is inserted between the rotating disk and gear 63. Further, rotating disk 65 is mewhen carrier wheel 9 is rotated.
  • disc 80 is mounted on shaft 28 which drives carrier wheel 9.
  • Disk 80 is subdivided into four adjacent annular sections on its periphery. In one sector of each ring space, there can'be inserted a permanent magnet 81, six of which are shown in the figure.
  • disk 80 is surrounded by a supporting member 82 on which reed contacts 83 are mounted.
  • Reed contacts '83 are arranged so that they can be actuated by permanent magnet 81.
  • supporting member 82 with reed contacts 83 and disc 80 with permanent magnets 81 By providing supporting member 82 with reed contacts 83 and disc 80 with permanent magnets 81, a certain combination of re'edfcontacts is closed in eachof the four rotational positions of shaft 28. In this fashion, characteristic switching positions are obtained for each of the four rotational positions.
  • Reed contacts 83 form part of the circuitry so that blade contacts 24 of carrier wheel 9 are connected to that, part of the measuring equipment,
  • Carrierwheel 9 is provided with four clamps which are symmetrically distributed over the periphery of the carrier wheel. Geneva wheel drive 30 effects a 90 rotation of the carrier wheel in the direction of arrow 84shown in FIG. 2.
  • each clamp 15 passes in succession through feed station I, adjustment station ll, test station III, and ejection station IV. Potentiometers 18 stored in feed duct 10 are in succession inserted into clamps 15 of carrier wheel 9 at the feed station.
  • the feed duct can be supplied with the potentiom- I etersby means of a conventional vibrating device.
  • potentiometer 18 in adjustment station II.
  • the slider is moved into a well-defined basic position, i,e., the slider is moved to one end of the resistor body. This is done while voltage comparison measurements are made, as described below with reference to the circuit scheme shown in FIG. 11.
  • the three terminal contacts of the potentiometer 18 are denoted by a, b, and c, with c denoting the slider contact.
  • a constant-voltage source U is connected to contacts b and c.
  • a calibrating potentiometer 18a is connected in parallel to potentiometer 18.
  • the sliders of the two otentiometers are connected to a differential amplifier D which can actuate electric clutch 70.
  • screwdriver tip 54 is kept in the depressed position until the current to the rotating magnet is interrupted. This results in a signal which initiates the search for the zero point. When this condition has been reached,-front end 54' of screwdriver tip 54 enters into the'screw groove on the spindle of potentiometer l8.
  • FIG. 12 shows the schematic circuit in which potentiometer 18 is connected to the constant-current source I and to oscilloscope 4.
  • the two terminal contacts of the potentiometer are denoted bye and b, and the slider contact is denoted by c.
  • Constant-current source .I is connected to contacts a and c of potentiometer 18.
  • the vertical deflection plates of oscilloscope 4 are connected to contaxts b and c of potentiometer l8, and the horizontal deflection plates are connected to contacts a and c. in the case of wire-wound potentiometers, the output current of constant-current source J typically amounts to approximately 1 mA.
  • Typical patterns appear on the display screen of the oscilloscope during potentiometer testing.
  • the oscilloscope is adjusted so that an ideal total resistance of the potentiometer covers the entire width of the calibrated oscilloscopescreen section.
  • An ideal wire potentiometer results in a straight line which covers the entire width of the oscilloscope screen.
  • FIGS. 13a through 13d show typical test patterns which were obtained with defective wirewound potentiometers.
  • the straight line is interrupted by a pulse which indicates that one point of the resistor is defective and causes noise. The end of the line is not reached in FIG.
  • FIG. 13b is a typical test pattern obtained with a film potentiometer whose parameters are still within the tolerance limits. The pattern is characterized by large noise peaks which reach their maximum values at the ends of the resistance film. A typical test criterion is that the noise peaks at the ends of the resistance film must be situated within an interval which does not deviate more than percent from the total resistance. ln the rest of the screen area, the noise voltage must not pass beyond the dashed line.
  • the cycle time of testing is determined by the time interval during which each potentiometer is retained in evaluation station lll. Testing in evaluation station Ill requires more time than testing in any other station, because slider c of potentiometer 18 is relatively slowly moved in test station "I. Consequently, circuits which prevent carrier wheel 9 from being rotated before all test operations have been performed are not required. In order to rotate carrier wheel 9 by 90, it suffices to provide a key, e.g., a foot switch, which is depressed by the operator as soon as testing in evaluation station III has been completed.
  • a key e.g., a foot switch
  • An apparatus for testing potentiometers having a resistor element with two end terminals and a slider contact which traverses said resistor in response to rotation of a spindle comprising a carrier having a plurality of potentiometer supports at spaced points thereon, and a plurality of devices positioned at stations adjacent to said carrier, said carrier being movable to locate each support successivelyat said stations in a predetermined sequence, wherein the improvement comprises an adjusting device at one of said stations including rotary driving means engageable with the spindle of a potentiometer in a support on said carrier adjacent to said one station,
  • an evaluation device at a subsequent one of said stations including second rotary driving means engageable with the spindle of a potentiometer in a support on said car,- rier adjacent to said subsequent station,
  • said evaluation device includes rotation limiting switches, and adjustable actuating means therefor, driven by said second driving means said limiting switches preventing further rotation of said second driving means and said spindle in a given direction when points adjacent the ends of said resistor predetermined by adjustment of said actuating means are reached by the slider contact.
  • said second rotary driving means includes a spring biasing said shaft tip portion toward a potentiometer spindle, and an actuator operable to shift said shaft tip portion away from a potentiometer spindle.
  • said wheel comprises a square base rotatably mounted on a centrally-positioned shaft, said potentiometer supports being exchangeably mounted on the peripheral faces of said base.
  • each of said potentiometer supports includes three contacts arranged to electrically engage the three contacts of an inserted potentiometer.
  • An apparatus for testing potentiometers having a resistor element with two end terminals and a slider contact which traverses said resistor in response to rotation of a spindle, comprising a rotating carrier having a plurality of potentiometer supports spaced around the periphery thereof, and a plurality of devices positioned at stations adjacent to said carrier, said carrier being movable to locate each support successively at said stations in a predetermined sequence, wherein the improvement comprises a feeder device at a first one in sequence of said stations comprising a vertically extending feed duct adapted to receive a stack of potentiometers, the interior profile of said duct being such that potentiometers can be introduced only when they are in a predetermined position, said duct having its lower portion adjacent to said carrier and having an opening therein facing said carrier, and I a feeder device movable radially with respect to said carrier and engageable with the'lowermost potentiometer in said feed duct to move said lowermost potentiometer through said opening into a potent
  • second control means sequentially actuating said second driving means to engage the spindle, drive the associated slider contact from the starting point to a predetermined point adjacent to the opposite end of the resistor element, reverse the direction of drive, and return the slider contact to the'starting point.
  • the apparatus as claimed in claim 16 including a motor operatively coupled to said feeder device, and two adjustable stop switches electrically joined to said motor and actuated by the motion of said feeder device to limit the range of movement thereof.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Apparatuses And Processes For Manufacturing Resistors (AREA)
  • Measuring Instrument Details And Bridges, And Automatic Balancing Devices (AREA)
  • Measurement Of Resistance Or Impedance (AREA)
  • Testing Electric Properties And Detecting Electric Faults (AREA)
  • Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
  • Adjustable Resistors (AREA)
  • Feedback Control In General (AREA)
US00332008A 1972-02-17 1973-02-12 Apparatus for testing potentiometers Expired - Lifetime US3852665A (en)

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JP (1) JPS5618905B2 (US07922777-20110412-C00004.png)
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Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3969618A (en) * 1974-11-29 1976-07-13 Xerox Corporation On line PROM handling system
US4987372A (en) * 1989-08-01 1991-01-22 Lutron Electronics Co., Inc. Potentiometer state sensing circuit
US6075370A (en) * 1998-03-27 2000-06-13 Aladdin Enterprises, Inc. Method of calibrating a potentiometer
US6181141B1 (en) * 1999-01-22 2001-01-30 Honeywell Inc. Failsafe monitoring system for potentiometers and monitor interface
US20040029531A1 (en) * 2000-06-30 2004-02-12 Georg Lohr Self-diagnosing transmission system
US20080100303A1 (en) * 2006-08-10 2008-05-01 Honeywell International, Inc. Circuit and method for determining potentiometer wiper resistance
CN103191868A (zh) * 2013-04-07 2013-07-10 广东升威电子制品有限公司 电位器自动检测设备
US20130229195A1 (en) * 2012-03-05 2013-09-05 Azbil Corporation Potentiometer degradation evaluating method
CN104122429A (zh) * 2014-07-24 2014-10-29 富阳兴远仪器仪表经营部 微小电压测量装置
CN104237644A (zh) * 2014-09-28 2014-12-24 潘柯文 一种单双联电位器多功能测试电路
CN105834128A (zh) * 2016-06-14 2016-08-10 东莞市钺河自动化科技有限公司 一种电位器自动检测设备
CN107490734A (zh) * 2017-07-27 2017-12-19 成都国盛科技有限公司 玻璃釉电位器自动测试设备
CN109683076A (zh) * 2018-12-19 2019-04-26 芜湖恒美电热器具有限公司 发热芯外壳耐压自动测试装置
CN110899152A (zh) * 2019-12-05 2020-03-24 东莞市钺河自动化科技有限公司 自动拨盘电位器测试机
CN113825085A (zh) * 2021-08-17 2021-12-21 深圳市豪恩声学股份有限公司 一种音量电位器检测设备、系统及方法
CN114878862A (zh) * 2022-06-30 2022-08-09 南通玉蝶电子陶瓷有限公司 一种预调电位器测试机

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Publication number Priority date Publication date Assignee Title
JPS51141347A (en) * 1975-05-30 1976-12-06 Nippon Electric Co Variable resistance examining device
JPS5482273A (en) * 1977-12-14 1979-06-30 Nakamatsu Yoshiro System for measuring variable resistor
CN117310422B (zh) * 2023-12-01 2024-02-23 四川永星电子有限公司 一种火工品电阻器性能测试方法及系统

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US2840784A (en) * 1953-12-01 1958-06-24 Western Electric Co Method of testing electrical devices
US3160810A (en) * 1960-06-20 1964-12-08 Sperry Rand Corp Potentiometer linearity testing machine with means to prevent grooving of wiper
US3457503A (en) * 1965-01-13 1969-07-22 Litton Industries Inc Potentiometer linearity and conformity checking apparatus including program storage means

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US3094212A (en) * 1961-12-14 1963-06-18 Gen Precision Inc Automatic component tester
FR1498864A (fr) * 1965-11-15 1967-10-20 Ibm Méthode et dispositif utilisés pour vérifier mécaniquement et électriquement laqualité des connexions soudées
FR2067120B1 (US07922777-20110412-C00004.png) * 1969-11-07 1974-06-14 Cit Alcatel

Patent Citations (3)

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Publication number Priority date Publication date Assignee Title
US2840784A (en) * 1953-12-01 1958-06-24 Western Electric Co Method of testing electrical devices
US3160810A (en) * 1960-06-20 1964-12-08 Sperry Rand Corp Potentiometer linearity testing machine with means to prevent grooving of wiper
US3457503A (en) * 1965-01-13 1969-07-22 Litton Industries Inc Potentiometer linearity and conformity checking apparatus including program storage means

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3969618A (en) * 1974-11-29 1976-07-13 Xerox Corporation On line PROM handling system
US4987372A (en) * 1989-08-01 1991-01-22 Lutron Electronics Co., Inc. Potentiometer state sensing circuit
US6075370A (en) * 1998-03-27 2000-06-13 Aladdin Enterprises, Inc. Method of calibrating a potentiometer
US6469527B1 (en) 1998-03-27 2002-10-22 Todd G. Gardner Method of calibrating a potentiometer
US6181141B1 (en) * 1999-01-22 2001-01-30 Honeywell Inc. Failsafe monitoring system for potentiometers and monitor interface
US8013468B2 (en) 2000-06-30 2011-09-06 Schleifring Und Apparatebau Gmbh Self-diagnosing transmission system
US20040029531A1 (en) * 2000-06-30 2004-02-12 Georg Lohr Self-diagnosing transmission system
US8772985B2 (en) 2000-06-30 2014-07-08 Schleifring Und Apparatebau Gmbh Self-diagnosing transmission system
US20080100303A1 (en) * 2006-08-10 2008-05-01 Honeywell International, Inc. Circuit and method for determining potentiometer wiper resistance
US7550981B2 (en) 2006-08-10 2009-06-23 Honeywell International Inc. Circuit and method for determining potentiometer wiper resistance
US20130229195A1 (en) * 2012-03-05 2013-09-05 Azbil Corporation Potentiometer degradation evaluating method
US9255951B2 (en) * 2012-03-05 2016-02-09 Azbil Corporation Potentiometer degradation evaluating method
CN103191868A (zh) * 2013-04-07 2013-07-10 广东升威电子制品有限公司 电位器自动检测设备
CN104122429A (zh) * 2014-07-24 2014-10-29 富阳兴远仪器仪表经营部 微小电压测量装置
CN104122429B (zh) * 2014-07-24 2016-09-21 富阳兴远仪器仪表经营部 微小电压测量装置
CN104237644A (zh) * 2014-09-28 2014-12-24 潘柯文 一种单双联电位器多功能测试电路
CN105834128A (zh) * 2016-06-14 2016-08-10 东莞市钺河自动化科技有限公司 一种电位器自动检测设备
CN105834128B (zh) * 2016-06-14 2017-12-15 东莞市钺河自动化科技有限公司 一种电位器自动检测设备
CN107490734A (zh) * 2017-07-27 2017-12-19 成都国盛科技有限公司 玻璃釉电位器自动测试设备
CN109683076A (zh) * 2018-12-19 2019-04-26 芜湖恒美电热器具有限公司 发热芯外壳耐压自动测试装置
CN110899152A (zh) * 2019-12-05 2020-03-24 东莞市钺河自动化科技有限公司 自动拨盘电位器测试机
CN113825085A (zh) * 2021-08-17 2021-12-21 深圳市豪恩声学股份有限公司 一种音量电位器检测设备、系统及方法
CN114878862A (zh) * 2022-06-30 2022-08-09 南通玉蝶电子陶瓷有限公司 一种预调电位器测试机
CN114878862B (zh) * 2022-06-30 2022-09-09 南通玉蝶电子陶瓷有限公司 一种预调电位器测试机

Also Published As

Publication number Publication date
DE2207525B2 (de) 1976-03-25
GB1418934A (en) 1975-12-24
DE2207525A1 (de) 1973-10-04
JPS5618905B2 (US07922777-20110412-C00004.png) 1981-05-02
FR2172399A1 (US07922777-20110412-C00004.png) 1973-09-28
FR2172399B1 (US07922777-20110412-C00004.png) 1976-06-11
JPS4893957A (US07922777-20110412-C00004.png) 1973-12-04

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