Abstract: A cash processing apparatus comprises a housing provided with a depositing and dispensing section; a display section; a coin insertion section at a position at one side of a central part in a width direction of the housing and into which the coin is inserted; a coin placing section in the housing and having a coin placing surface for temporarily placing the coin, connecting to the coin insertion section side by side and extend to an opposite side across the central part in the width direction of the housing from the coin insertion section to form a shape elongated in the width direction; and a settlement module, wherein both a distance between the coin insertion section and one side end of the housing which is closest to the coin insertion section and a distance between the coin placing section and the other side end of the housing which is closest to the coin placing section are smaller than a depth distance of the coin placing section.

Abstract: The disclosure is directed at a method and system for a pull-cord sensor assembly that includes an activation portion including a magnet portion for generating a magnetic field; a sensor portion for sensing a level of the magnetic field level; a comparator for comparing the level of the magnetic field with a threshold value; and a pull cord integrated with the activation portion.

Abstract: Throughout the world, there is growing trend by investors to protect wealth by holding silver and gold coins and bars. Unfortunately, there are also a growing number of counterfeit coins and bars coming into in circulation. This situation cries out for an affordable method that can be used by untrained investors to quickly and reliably discriminate authentic coins and bars from counterfeit ones without causing damage to their coins and bars. The disclosed method fills this need by the use of a combination of conventional and novel designed pieces of equipment for measuring the following three characteristics of a coin; (1) size, (2) weight, and (3) relative terminal velocity on a magnetic slide. The results of these measurements can be used to unambiguously discriminate pure silver and pure gold investment coins and bars from counterfeit ones and can also be helpful in evaluating 22-karat gold coins and pure platinum coins.

Abstract: A method for calculating sheet conductivity with an absolute working distance measurement includes selecting a motor frequency fM for a motor having a first magnet disposed on a shaft, tuning a motor voltage VM for the motor, measuring a no-load power of the motor, inserting a material adjacent the first magnet, tuning the motor frequency to fM, measuring the on-load power of the motor, measuring the absolute working distance and calculating the sheet conductivity of the material.

Abstract: Structures, systems, and methods verify the authenticity of a precious metal unit. A “ping bar” is designed to have a distinctive sound only if authentic and unadulterated. A “waffle bar” is shaped to discourage adulteration, damage, or counterfeiting and to facilitate easy core sampling and assay of the constituent metal's purity. Reeded edge features may additionally be employed to discourage tampering. An RFID device and a global registry system verify various attributes and ownership of the precious metal units.

Abstract: Systems and methods for calibrating a coin sensor are disclosed herein. An auto-calibrating coin sensor configured in accordance with one embodiment of the disclosure includes a movable carrier holding at least one test coin or other test object. The carrier can move the test object past or through the coin sensor to calibrate the coin sensor. Embodiments of the present technology can include rotatable and linearly moveable carriers that are configured to move an attached test object through a coin sensor. Additionally, auto-calibrating coin sensors in accordance with the present technology can be configured to initiate an auto-calibration based on the commencement of a coin counting session, a set schedule, a temperature change, and/or other events.

Abstract: A method of examining a coin for determining the validity of its denomination, comprises the steps of moving a coin through a passageway, sensing said moving coin in said passageway with one or more sensors to interact with said moving coin and provide at least two values indicative of the said coin, calculating two or more coin features by using said at least two values, determining that said coin features values lie between predetermined minimum and maximum stored values, applying predetermined coefficients of weighted-error to each of said coin features, calculating weighted-error correlation coefficients using two or more of the said coin feature values, and determining validity when the said calculated weighted-error correlation coefficient is above predetermined minimum stored values, or when said coefficient is the maximum of all calculated coefficients.

Abstract: The present invention relates to coin value safeguard devices and methods by determining and monitoring the eye appeal of a coin and labeling that eye appeal on an appropriate holder of the coin such that the eye appeal is displayed to a viewer of the holder, and that coin's value is thus increased. Appropriately knowledgeable graders assess a coin's eye appeal by determining the coin's axial ultimate refractory angle(s) (AURA) and assigning an AURA rating to the coin. The coin image is stored in a database where it may be compared to secondary temporal images of the coin as necessary to determine whether coin doctoring has been employed.

Abstract: An imaging unit images a subject having an unevenness pattern on a surface. The imaging unit includes: a surface light source that emits with a constant output illumination light illuminating the surface of the subject; an imager that receives reflected light reflected by the surface of the subject; and a beam splitter that is arranged at a location at which the illumination light emitted from the surface light source and the reflected light incident on the imager intersect with each other. The illumination light emitted from the surface light source is incident on the surface of the subject via the beam splitter. The reflected light reflected by the surface of the subject is incident on the imager via the beam splitter. The illumination light incident on the surface of the subject includes parallel light that is perpendicularly incident on the surface of the subject, and diffused light.

Abstract: A coin recognizing device is configured in which a main-judgment-frame registration unit registers main judgment frames for each denomination including value ranges corrected so that a value range corresponding to data of at least one of recognition elements does not overlap with a value range corresponding to the same recognition element of any other denominations, an auxiliary-judgment-frame registration unit registers auxiliary judgment frames for a specific denomination including value ranges of the recognition elements of a coin of which data does not fall within the main judgment frames for the specific denomination but is to be judged as a coin of the specific denomination, and a judging unit judges a coin of which data falls within either the main judgment frames or the auxiliary judgment frames and does not fall into the reject judgment frames as a coin of a denomination corresponding to the main judgment frame.

Abstract: A thickness/material sensor samples an output signal output from a self-oscillating circuit at a specific sampling interval; acquires sampling data sampled in a specific sampling time period; reduces, among the acquired sampling data, a weight on the sampling data sampled near both ends of the specific sampling time period than a weight on other sampling data and outputs weighted sampling data; and calculates effective values of an output signal in the specific sampling time period from the weighted sampling data.

Abstract: A deformed-coin detector accurately detecting a deformed coin without being affected by a variation in transporting speed of a coin. A coin transported along a coin transporting face comes into contact with detecting elements of coin-thickness detecting bodies, the detecting elements move by a distance corresponding to the dimension of the coin in its thickness direction and simultaneously, light shielding portions of the coin-thickness detecting bodies move. A light detecting portion detects a light shielding amount that varies due to movement of the light shielding portions. A coin denomination determining unit determines a denomination of the coin transported along the coin transporting face and reads a reference light-shielding amount pre-stored in a reference light shielding amount storing unit regarding the denomination.

Abstract: The present invention relates to coin value safeguard devices and methods by determining and monitoring the eye appeal of a coin and labeling that eye appeal on an appropriate holder of the coin such that the eye appeal is displayed to a viewer of the holder, and that coin's value is thus increased. Appropriately knowledgeable graders assess a coin's eye appeal by determining the coin's axial ultimate refractory angle(s) (AURA) and assigning an AURA rating to the coin. The coin image is stored in a database where it may be compared to secondary temporal images of the coin as necessary to determine whether coin doctoring has been employed.

Abstract: A method of examining a coin for determining the validity of its denomination, comprises the steps of moving a coin through a passageway, sensing said moving coin in said passageway with one or more sensors to interact with said moving coin and provide at least two values indicative of the said coin, calculating two or more coin features by using said at least two values, determining that said coin features values lie between predetermined minimum and maximum stored values, applying predetermined coefficients of weighted-error to each of said coin features, calculating weighted-error correlation coefficients using two or more of the said coin feature values, and determining validity when the said calculated weighted-error correlation coefficient is above predetermined minimum stored values, or when said coefficient is the maximum of all calculated coefficients.

Abstract: A coin recognizing device is configured in which a main-judgment-frame registration unit registers main judgment frames for each denomination including value ranges corrected so that a value range corresponding to data of at least one of recognition elements does not overlap with a value range corresponding to the same recognition element of any other denominations, an auxiliary-judgment-frame registration unit registers auxiliary judgment frames for each denomination including value ranges of the recognition elements of a coin of which data does not fall within the main judgment frames but is to be judged as a coin of a specific denomination, a reject-judgment-frame registration unit registers reject judgment frames for each denomination including value ranges of the recognition elements of a coin of which data falls within the main judgment frames or the auxiliary judgment frames but is not to be judged as a coin of a specific denomination, and a judging unit judges a coin of which data falls within either

Abstract: According to one aspect of the invention, there is provided a metal disk discrimination apparatus including: two magnetic sensors configured to sandwich a target metal disk, the magnetic sensor including: a core having: leg portions exhibiting opposite magnetic polarities, the leg portion having an end face facing the target metal disk, and a connection portion magnetically connecting the leg portions; and coils respectively wound on the leg portions; an oscillation circuit that passes an alternating current through the coil; and a signal processing unit that determines a shape of the target metal disk by comparing an output signal of the magnetic sensors with a reference value, the output signal corresponding to a change in impedance of the coils. A radius of curvature of the end face in a part adjacent to another end face is not larger than a radius of the target metal disk.

Abstract: A coin sensor and method of identifying coins by size and also discriminating invalid coins includes a portion of a coin track (63) over which coins (14) pass in a single file, an illumination source (92) for illuminating at least portions of the coins (14) as the coins move along the coin track (63), an optical detector (95) spaced from the coin track (63) for detecting a size of at least a portion of each coin passing the coin sensor along the coin track, and a telecentric lens (94) positioned between the optical detector (95) and the coin track (63), such that the portion of each coin passing the optical detector (95) is seen to have an apparent size and configuration independent of a variation in distance of the coin from the telecentric lens (94) as each coin moves along the coin track (63). The optical sensor and detector (90) can be angled to assist in preventing stray light from the bottom of the coins from being transmitted to the detector (95).

Abstract: Methods and systems for detecting coin fraud in coin-counting machines and other devices that count and/or sort coins and other objects. In one embodiment, the method includes discriminating multiple coins to determine a number of real coins and a number of faux coins. In one aspect of this embodiment, the faux coins can have one or more coin characteristics falling generally close to corresponding characteristics of the real coins. The method can further include determining a quotient based on the number of real coins and faux coins. If the determined quotient is greater than or equal to a selected threshold value, then the transaction can be identified as being possibly fraudulent. In the event of a possibly fraudulent transaction, the method can include controlling the transaction, for example, by returning any uncounted coins to a user, or by halting the transaction.

Abstract: A coin discriminating device has a first camera for producing a first image of a first surface of a coin, a second camera for producing a second image of a second surface of the coin, and a processor, e.g. a computer, which is operatively connected to the first and second cameras. The processor analyzes the first and second images in order to determine a type of the coin.

Abstract: A coin sensor is provided for more accurately assessing the authenticity of a coin passing through a vertical channel where the channel is sized to accommodate different diameter coins. In the present invention, magnetic coils are deployed on the side of the channel to measure magnetic flux, which is converted to digital signals and compared to stored values to assess the diameter, thickness, and material of the coin. To reduce the tolerances associated with the varying path of the coin, the sensors have been provided with cores having generally straight and parallel upper and lower surfaces aligned perpendicular to the path of the coin to remove the variances in the overlapping coin area as the coin.

Abstract: Improved currency scanners for coins and bills which are connected to computers having memories which contain information concerning coinage or printing errors and scarce coins or bills and which compare each coin or bill as it is scanned to identify and alert the user to such coins or bills.

Abstract: A sensor for a coin acceptor includes an inductor connected in a series resonant circuit. The sensor coils are arranged in a series resonant configuration with the resonant capacitance made up of two identical capacitors, one on either side of the sensor. The series resonant configuration reduces the effects on sensor readings of common mode noise on the coin acceptor power supply.

Abstract: The energy of the sound radiation caused by the impact of the coin to be analyzed upon a hard surface is split into different frequency bands, the energy of every such band is obtained and the ratios between them are then worked out, obtaining parameters that are then compared against values representing valid coins. The device includes a bank of filters (6, 7 and 8), integrators (9, 10 and 11) connected to the outlet of the filters and capable of being activated from a microprocessor (17) and an analogue-digital converter to which the output of the various integrators is then connected through a multiplexer.

Abstract: The present invention provides apparatus, systems, and methods for accurately calibrating a pressure sensor which is incorporated into a lead, e.g., a pacemaker lead, prior to implant into a patient. A calibration vessel is provided which has a housing which forms a reservoir for containing the portion of the lead having the pressure sensor. The vessel also has a connector for receiving a reference pressure into the reservoir, and a sealable opening for receiving the distal end of the lead that carries the pressure sensor. The calibration vessel can be used in a system comprising an electronic display module and an external pressure reference, for establishing an accurate sensor baseline for zero pressure; and can also be used in a system comprising an electronic display module, a reference pressure input source, and a manometer for establishing an accurate scale factor for the lead pressure sensor.

Abstract: A testing mechanism for testing the pressure at which a relief valve will open due to excessive pressure in a fluid system having fluid carrying conduits, the mechanism includes a stop member having a first position whereat the stop member exposes the relief valve to the fluid system and a second position whereat the stop member seals or isolates the relief valve from the fluid system during a test of the relief valve. A pressure gauge is positioned between the stop member and the relief valve for sensing the pressure of fluid engaging the relief valve when the stop member is in the second position. A pressure applying mechanism applies pressure to the relief valve when the stop member is in the second position. A barrier positioned between the pressure applying mechanism and the relief valve prevents fluids other than fluid within the fluid system from engaging the relief valve when the pressure applying mechanism is actuated.

Abstract: A transmitter in a process control system includes diagnostic circuitry for determining condition of a pressure sensor. The pressure sensor includes a pressure responsive structure and a capacitor coupled to the pressure responsive structure whereby capacitance of the capacitor varies in response to process pressure. Measurement circuitry determines capacitance which is transmitted over a process control loop using output circuitry. The diagnostic circuitry is coupled to the pressure sensor and provides a diagnostic input to the pressure sensor. The diagnostic input causes a change in the capacitance which is monitored to determine condition of the pressure sensor.

Abstract: A coin testing mechanism of the kind provided with a removable and replaceable cassette is described. The coin testing mechanism includes a plurality of coin storage tubes and means for dispensing coins from the storage tubes, and the removable cassette is an assembly which comprises a plurality of storage tube modules. Each of the modules comprises at least one storage tube, and the modules are retained in the assembly by releasable and reusable retaining means to enable exchanging one module of the cassette for another.

Abstract: Systems and methods for illuminating an object surface with light at varying angles of incidence and for optically evaluating the object surface for features and defects, etc. are disclosed. In a specific implementation the systems and methods, the target object comprises a coin and the illumination and evaluation techniques are used to accurately objectively evaluate the numismatic quality of the coin and/or identify the coin. Central to the illumination and evaluation techniques is the ability to apply a uniform confined beam of light to the surface of the target object to be imaged. The confined angles of incidence of the beam of light includes a perpendicular component angle of incidence range and a parallel component angle of incidence range relative to the object surface. The component ranges are defined such a light beam illuminates the object surface from a well-defined direction.

Abstract: A coin discriminator discriminates a genuine coin from a counterfeit on the basis of a real component and an imaginary component of an impedance of the coin produced from a high frequency alternating current bridge circuit and decides an amount of the coin when the coin is genuine. An automatic balancing circuit having a sufficiently long time constant is employed to detect variations in the real component and the imaginary component of the impedance due to insertion of the coin. Whether the coin is genuine or counterfeit is discriminated on the basis of peak values of both variations and when the coin is genuine, an amount of the coin is decided.

Abstract: A coin detector and counter comprising a coreless oblong transmitter coil and a coreless oblong receiver coil spaced apart on opposite sides of a coin path arranged to cause the entire diameter of each coin to pass between the coils. The maximum peak voltage generated in the receiver coil upon passage of each coin is measured as a determination of the conductance of each coin. By comparing the measured conductance of each coin with the known conductance of coins, each coin is thereby identified and counted.

Abstract: A method and system for accurately and objectively evaluating the numismatic quality of a test coin and/or for fingerprinting the test coin for purposes of identification is disclosed. Central to both the grading and fingerprinting aspects of the invention is the exact, numerical evaluation of any detracting marks on each side of the coin. In particular, each detracting mark on the coin is identified, located and measured. An assigned quantity representative of the detracting significance of each mark is then calculated by adjusting the measured surface area of the mark by a factor representative of the relative grading importance of the area on the coin where the mark is located. The assigned quantities and corresponding mark location identifiers are stored as a unique test coin fingerprint. The grading aspect further requires that the assigned quantities for each side be separately summed and correlated into a grade via comparison with a preexisting database of values representative of numismatic grades.

Abstract: An apparatus for testing a coin provides first, second, and third digital signals respectively indicative of the coin's metallic content, diameter, and thickness. A microprocessor-based control circuit identifies the coin as being one of a number of known coins in response to the digital signals. If the coin does not match any of the known coins, it is identified as a false coin, for example, a slug or foreign money.

Abstract: A coin discriminating device which can carry out accurate coin discrimination free of error caused by drift and changes in the thermal characteristics of the detecting elements. The coin type is discriminated by detecting data on the magnetic characteristics of coins and comparing the detected data with reference data and also by computing the difference between the maximum and minimum values of the detected data and comparing the computed result with the reference value.

Abstract: A numismatic detector including a laser generator, a light collimator to form generated laser light into discrete beams, a coin holder to precisely position coins to be detected, and a film pack adapted to receive reflection of discrete light beams from the surface of the coin.

Abstract: The level of a stack of coins in a stack tube is monitored by an ultrasonic transducer disposed above the stack tube. The transducer directs a train of ultrasonic pulses down towards the top of the stack and measures the transit time between the emitted and reflected pulses. The monitoring apparatus is particularly suitable for use in a gaming, amusement, vending or change machine which has a number of stack tubes from which coins are payed out by a payout device under the control of a control unit.

Abstract: A coin sorting apparatus in which the oscillation constants of oscillators change with the passage of a coin, and the amount of change in each of the oscillation constants or a value converted therefrom is compared with a reference value of a coin to be identified which is stored in a memory to identify whether the coin is genuine and the class thereof. Whether the reference values for each coin are corrected is determined by a plurality of counters which correct the reference values of corresponding classes of coins when their counts exceed a predetermined set value. At the same time, when the inserted coin is identified as genuine, a corresponding counter is activated, thus improving the performance of eliminating spurious coins without reducing the acceptability of genuine coins even under ambient temperature changes or secular variations of component elements with time.

Abstract: A device for testing the magnetic properties of coins in coin operated apparatus such as parking meters, used in conjunction with a coin diameter testing device. The device includes a double arm rocker lever provided on a side wall of a coin guiding duct. A first arm of the rocker lever is equipped with a permanent magnet and the latter extends through an opening of the side wall into the range of a coin which has been inserted into the coin guiding duct and which temporarily rests on a coil support. A second arm of the rocker lever includes a locking bracket which can be controlled so as to be in and out of engagement with a testing segment required for the test for determining the diameter of coins.

Abstract: An improved electronic coin validator responsive to detect a plurality of different denominations of valid coins. The validator is constructed around a microcomputer (60). A single coil (30) in the tank circuit of an oscillator is used to determined content. The output of the oscillator is rectified (111, 112) and filtered (115, 116) to give an output signal (120) having a magnitude proportional to the envelope of the oscillator output. An improved diameter detection arrangement using only two LED/optodetector pairs (32, 132, 35, 135) is used to determined diameter by determining the actual average velocity of the coin as it travels down the runway by the sensors and thus to calculate a chord length using the calculated average velocity and a time period (T3) measured as the coin passed the sensors. A plurality of vend prices may be set by the state of a plurality of dip switches (69) and the microcomputer also provides control signals (150, 156) to a laundry machine.

Abstract: A method and apparatus for coin examination which transmits on one side of a coin a low frequency electromagnetic field from a transmitter inductor which is part of a transmitter circuit, monitors the frequency of the low frequency electromagnetic field, receives a portion of the field on the other side of the coin with a receiving inductor which is part of a receiving circuit, measures the phase shift between the transmitted signal and the received signal, and determines if the measured phase shift corresponds to the phase shift for an acceptable coin at the monitored frequency.

Abstract: A slug rejector in which a coin-testing oscillator provides, when a coin or slug passes through the field of its coil, an output in its linear range which is used to actuate a coin diverting gate. To stabilize the operation of the coin-testing oscillator, a reference oscillator is provided which is continuously in operation. The output of the reference oscillator is used to generate correcting signals which are fed back to the oscillator circuit to maintain its output at a constant amplitude. The same correcting signals are also fed back to the coin-testing oscillator whereby its output for a predetermined coin or slug is a constant repeatable value.

Abstract: A coin testing apparatus comprises transmitting and receiving coils on opposite sides of a coin passageway. The transmitting coil is connected to high and low frequency oscillators. In the high frequency channel the signal is amplitude controlled by a voltage controlled amplifier rectified by a rectifier and smoothed by a long time-constant circuit. The initial rise in level caused by a coin entering between the coils is detected by an instantaneous level change comparator which responds to the rate of change of signal level at the output of the long time-constant circuit becoming equal to a preset threshold and causes a normally closed switch to be opened. When the switch is closed a comparator compares the signal with a reference value from a source and adjusts the gain of the amplifier until the signal corresponds to the reference value.

Abstract: The invention relates to a coin validator for use in a micro-processor controlled call coin box telephone instrument. The validator comprises first and second coil sets driven by square wave interrogation pulses. The arrangement of the coils is such that when a coin is in the coin-runway of the call coin box, one coil pair is used to interrogate the coin in the runway while the other coil pair provides environmental conditions apertaining to the runway. The information generated by both coil sets is combined thereby compensating for environmental changes and drift. Information pertaining to the relative response times of the secondary coils is then used to determine coin validity.

Abstract: A method and apparatus for coin examination which subjects one side of a coin to a low frequency electromagnetic field from a transmitter inductor driven by an astable oscillator and frequency divider, receives a portion of the field on the other side of the coin with a receiving inductor, amplifies the output of the receiving inductor with a non-linear amplifier, and measures the phase shift between the signal driving the transmitter inductor and the amplifier output.

Abstract: The coins (8) are thrown into a common coin channel and affect the field of a coil (2; 52). The coil core consists either of several U- or E-cores (54, 55) arranged at right angles to the coin travel direction (5) in direct or spaced-apart adjacency, or of an oblong core (3) U- or E-shaped in cross section which lies at right angles to the coin travel direction. The spacing of the two outermost cores (54, 55) and/or the length of the core (3) is dimensioned to be of such a size that the coins (8) of varying diameter affect the coil field differently. The circuit for determining the effect on the field can comprise, for example, an alternator supplying the coil (2; 52) and a further coil (7; 53) coupled to the coil and connected to a comparison circuit. By means of the coil checker according to the invention it is possible to reliably test and determine even coins having greatly varying diameters.

Abstract: A coin testing apparatus (10) comprises a coin passageway, a coin track (13) along which coins pass on their edges through the coin passageway and an inductor (16) adjacent the coin passageway. The inductor is connected in an oscillating circuit (40) so that the inductor (16) produces an oscillating magnetic field in the coin passageway. The frequency of the oscillating circuit is measured using a counter (41). A number representative of the idle frequency is stored in register (44). When a coin passes the inductor (16), the apparatus (10) detects whether the resulting frequency shift corresponds to the shift for an acceptable coin by comparing the difference between the number stored in register (44) and the number stored in counter (41) with a number previously stored in memory (48). The inductor (16) is oblong and has its major axis perpendicular to the track so that the arrangement is sensitive to variations in diameter over a large range of diameters.

Abstract: A detecting magnetic coil is mounted adjacent the authenticity-determining magnetic coil of an electronic slug rejector to distinguish between authentic coins and any copper slugs which might cause the authenticity-determining coil to produce an output which closely simulates the output which that authenticity-determining coil produces in response to authentic coins. The signal from that detecting coil is used to control the accept/reject gate of that electronic slug rejector; and it will effect movement of that gate to "accept" position in the event it detects a non-cupreous object but it will not effect such movement of that gate in the event it detects a copper slug.

Abstract: An improved coin acceptor mechanism employing an oscillator and a resonant circuit for detecting the electromagnetic effect of valid and invalid coins passing through a coil of the tuned circuit. A particular linear coil configuration provides a unique signature for each coin including at least one maximum and one minimum amplitude level of resonant circuit current. A comparator establishes at least two electrical signal amplitude windows representative of each valid coin signature. A logic circuit responds only to the coin falling within the two electrical signal amplitude windows for actuation. A novel coil design and assembly are enclosed.

Abstract: A coin discriminating apparatus comprises two coils on opposite sides of a path for coins, one coil being connected to a signal generator so as to give repetitive abrupt flux changes and a gating device being provided for short circuiting the other coil but removing the short circuit a predetermined time delay after each flux change. A circuit is responsive to the amplitude of a voltage pulse which is produced across said other coil in response to each removal of the short circuit to discriminate between coins. This apparatus may form the second test of a two-test coin discriminating apparatus, wherein the first test measures a phase displacement caused by the coin passing between another pair of coils and this measurement is used to set the time delay to one of selected values, according to the expected coin, so that the voltage pulse will be of a constant amplitude for valid coins.

Abstract: A method and an apparatus for testing and identifying electrically conductive discs, such as coins or equivalent. According to the method the effect of each coin on a magnetic field generated by means of coils is measured, the measurement result obtained in this way is compared with the reference value, and the coin is accepted if the measured value is close enough to the reference value. The reference value is determined on the basis of the effect produced by a preselected reference coin upon a magnetic field preferably of the same magnitude as the magnetic field to be measured. The magnitude of the magnetic field is measured in two directions at least substantially perpendicular to each other and the effect of the coin upon the symmetry of the magnetic field to be measured is taken into account by means of an additional coil placed at least substantially in the symmetry plane of the magnetic field to be measured.

Abstract: A coin, spurious coin and the like is passed in close proximity with the inductance of the resonant tank circuit of an oscillator and varies the losses of the tank circuit and thereby the amplitude of a signal produced by the oscillator in accordance with the metal content of the coin, and the like. The signal produced by the oscillator is converted to a control signal having an amplitude which when in a predetermined range indicates an acceptable coin and which when outside the range indicates a rejectable spurious coin, and the like. After passing the inductance, the coin is selectively directed to an accepted location or a rejected location in accordance with the amplitude of the control signal. A passive resonant circuit is also provided in close proximity to but electrically unconnected to the resonant tank circuit for sensing the dimensions of the coin.