GB1564723A - Coin and token-freed apparatus - Google Patents

Coin and token-freed apparatus Download PDF

Info

Publication number
GB1564723A
GB1564723A GB828576A GB828576A GB1564723A GB 1564723 A GB1564723 A GB 1564723A GB 828576 A GB828576 A GB 828576A GB 828576 A GB828576 A GB 828576A GB 1564723 A GB1564723 A GB 1564723A
Authority
GB
United Kingdom
Prior art keywords
coin
token
routeway
presence
apparatus according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB828576A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Post Office
Original Assignee
Post Office
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Post Office filed Critical Post Office
Priority to GB828576A priority Critical patent/GB1564723A/en
Publication of GB1564723A publication Critical patent/GB1564723A/en
Application status is Expired legal-status Critical

Links

Classifications

    • GPHYSICS
    • G07CHECKING-DEVICES
    • G07FCOIN-FREED OR LIKE APPARATUS
    • G07F1/00Coin inlet arrangements; Coins specially adapted to operate coin-freed mechanisms
    • G07F1/04Coin chutes
    • G07F1/046Coin chutes with means for dealing with jamming, e.g. by bent wires
    • GPHYSICS
    • G07CHECKING-DEVICES
    • G07FCOIN-FREED OR LIKE APPARATUS
    • G07F9/00Details other than those peculiar to special kinds or types of apparatus
    • G07F9/02Devices for alarm or indication, e.g. when empty; Advertising arrangements in coin-freed apparatus

Description

(54) COIN AND TOKEN-FREED APPARATUS (71) We, THE POST OFFICE, a British corporation established by statute, of 23 Howland Street, London W1P 6HQ, do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to coin- and tokenfreed apparatus having means for detecting the presence and position of a coin or a token blockage at specific locations in a routeway through the apparatus. One application of the invention is the detection of the presence and position of a coin jam in a pay telephone coin box.

When a coin jam occurs in a telephone coin box, it would be advantageous to be able to detemline remotely at the telephone exchange whether the coin jam is due to the cash box being full or whether it is due to some other cause. This would save time in initiating ap propriate action to empty the cash box or to free the coin jam. Any apparatus used for determining the cause of the coin jam must be compatible with the existing telephone system.

Accoremg to one aspect of the present invention, a coin and token freed apparatus includes a coin routeway extending from a coin or token entry to a cashbox, and detector means for detecting the presence and location of a blockage of one or more coins or tokens along the routeway, the detector means including a plurality of sensors spaced along the routeway each sensor being arranged to sense the presence of a coin adjacent it and provide an indication of its presence, and monitoring means for monitoring the sensors to determine the presence and location of a stationary coin or token blocking the routeway.

According to another aspect of the invention, a telephone system in which the direction of current flow in a conductor pair providing communication from a pay telephone having a coin and token freed apparatus to another telephone via a telephone exchange is reversed when communication is established and payment for a call is made at the pay telephone, the coin or token freed apparatus including a coin routeway extending from a coin or token entry to a cashbox and detector means including a plurality of sensors arranged along the routeway for detecting the presence and location of a blockage of coins or tokens, the pay telephone including at least one capacitor which is charged from the conductor pair whilst the current flow is reversed, the presence of a coin or token blockage causes at least one of the sensors to provide a path to earth from the capacitor, and means operative when the current reversal is cancelled to indicate at the exchange by way of a conductor of a pair, the resistance of a conductive loop which includes the conductor of the pair, and the resistance of which varies with the location of the coin and the one of the sensors which is sensing the presence of the coin to indicate at the exchange the location of the coin or token blockage.

One embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing which shows schematically features of a pay telephone coin box including a detector circuit for detecting the presence and position of coins jammed, or otherwise arrested at specific locations in the coin box.

Referring to the drawing, a telephone conductor pair for a pay telephone comprises legs A and B. The leg A is normally positive with respect to the leg B, but when a call is answered there is a reversal of line current which energises a relay C which causes un 1oozing of coan slots (not shown) associated with a coin runway 1, to allow insertion of appropriate coins. One example of a coin runway is shown in our co-pending Patent Application No. 45859/73, serial number 1,486,770. When a coin has rolled through the runway, the coin passes through either a coin reject chute 2 or a coin acceptance chute 3. The chute 2 allows coins which are not validated by a checking facility (not shown) associated with the coin runway to be returned to the calling party. The chute 3 allows validated coins to drop into a cash box (not shown).

As the coin passes through a coin routeway formed by the runway I and the chute 2 or the chute 3, a coin is guided by respective spring-loaded vanes 4 and 5 or 6 which ensure that the coin touches an earthed wall of the chute or runway. The presence of the coin between the earthed wall and the respective vanes 4, 5 or 6 connects the earth to one plate of a relevant one of two capacitors 7 and 8, via a line 9 or a line 10, respectively.

The other plates of the capacitors 7 and 8 are connected via a resistor 11 to the leg A.

A silicon controlled rectifier 12 is connected across the relay C, i.e. across the legs A and B, so that it is non-conductive when the leg A is positive with respect to the leg B, but can be triggered to conduct when the legs are in the reverse potential state. The gate electrode of the rectifier 12 is connected to a junction 13 between the capacitors 7 and 8 and the resistor 11. A zener diode 14 is connected between the cathode and the gate of the rectifier 12 to limit the gate-to-cathode voltage of the rectifier.

Assuming that a call has not yet been answered, the leg A will be positive with respect to the leg B. When a call is answered, the leg A becomes negative. If insertion of a coin has not caused a connection to earth (i.e. there is no jam) the gate and cathode of the rectifier 12 will be at the same potential. On the other hand, if insertion of a coin causes connection of the capacitor 7 or the capacitor 8 to earth, the potential difference between the gate electrode and the cathode of the rectifier 12 will rise to 50 volts, causing the rectifier 12 to conduct and short circuit the relay C, so that the relay is no longer operative to unlock the coin slots.

The capacitor 7 or 8 which is connected to earth by the coin jam charges, and the gate/ cathode voltage of the rectifier 12 therefore decreases. This does not, of course, affect the conductive state of the rectifier, which is maintained by a holding current flowing through the telephone conductor pair.

On completion of a telephone call, when the handset is replaced a switch at the instrument opens the circuit through the legs A and B. This causes the rectifier 12 to return to its non-conducting state.

In the event of a subsequent attempt to set up a call from the pay telephone, the rectifier 12 will trigger immediately on reversal of the line potential, because an earth condition will already be present at one of the capacitors 7 or 8. Since the rectifier 12 triggers rapidly, e.g. in approximately 1+ msecs., as compared with an operating time for the relay C of approximately 20 msecs., the relay remains unenergised, and the coin slots therefore remain locked. The exchange presents a "number unobtainable" tone, when a "pay tone" period ends, for the information of the calling party.

In order to allow determination, at the telephone exchange, of the position in the coin box at which a coin has been arrested, a resistor 15 is connected between the line 9 and the anode of a diode 16. The cathode of the diode is connected to the leg A. A further resistor 17 is connected between the line 10 and the anode of the diode 16.

For a line to be tested from the exchange, the normal line conditions are removed and a negative battery is used for the detection of faults. When the leg A is interrogated by a negative battery from the exchange, a circuit is completed through the leg A, the diode 16 and the resistor 15 and the line 9 to earth and/or through the diode 16 the resistor 17 and the line 10 to earth, depending upon the position of the jammed coin or coins. A return path is provided via the earth connection and the earth of the telephone exchange.

The resistance to the flow of current round the circuit is determined primarily by the resistance of the resistor 15 or the resistor 17, as the case may be. The resistance therefore gives an indication, at the telephone exchange, that a coin is jammed in the runway 1 or in the reject chute 2 (resistor 17) or that a coin is jammed in the acceptance chute 3 or that the cash box is full (resistor 15). In both cases, appropriate action can be taken to clear the coin jam or to empty the coin box. When a coin passes freely through the runway 1 and the chute 2 or the chute 3, the rectifier 12 is not triggered, because a short circuit is normally established between the two legs A and B of the telephone conductor pair during the "coin collection" period. The period is started by insertion of a coin and lasts for a given time interval.During this interval, the short circuit causes effective isolation of the detector circuit. Until the short circuit is removed, the rectifier 12 cannot conduct, and by the time the short circuit is removed the coin will have passed through the apparatus and cannot therefore carry the earth connection to the capacitor 7 or the capacitor 8.

A capacitor 18 provides a low resistance speech path across the relay C. A rectifier 19.

prevents the relay from operating under normal current flow, i.e. when the leg A is positive and the leg B is negative.

Although the operation of the circuit has been described above with respect to the use of conductive coins, it will be understood that any suitable conductive items, which will be referred to as conductive tokens, can by bridging a pair of electrical contacts cause a change in circuit capacitance which may be utilised to prevent further input of the conductive tokens and which can be remotely monitored.In addition, a detector circuit may be constructed which does not depend for its operation on a coin or token being conductive For example, if a light or other radiation beam is cut for more than a predetermined period by a falling coin or token, a circuit including the source of the light or other radiation and a detector can function to block the apparatus against the further insertion of coins or tokens, and to provide the remote indication of the position of the arrested coin or token.

Another signalling facility which may be added is a further sensor to detect when the cash box is partially, for example threequarters, full. If the three-quarter full con dition is signalled to the exchange, appropriate steps may be taken to have the cash box emptied before it becomes completely full and a blockage occurs.

WHAT WE CLAIM IS: 1. A coin and token-freed apparatus including a coin routeway extending from a coin or token entry to a cashbox, and detector means for detecting the presence and location of a blockage of one or more coins or tokens along the routeway, the detector means including a plurality of sensors spaced along the routeway each sensor being arranged to sense the presence of a coin adjacent it and provide an indication of its presence, and monitoring means for monitoring the sensors to determine the presence and location of a stationary coin or token blocking the routeway.

2. An apparatus according to claim 1, including means for inhibiting the operation of the detector means for a period after the insertion of a coin or token sufficient for a coin or token to have passed freely through the routeway.

3. An apparatus according to claim 1 or 2, wherein each sensor comprises a pair of electrical contacts, which when closed by a coin or token establish a conductive path to earth from a corresponding capacitor.

4. An apparatus according to claim 1 or 2, wherein each sensor comprises a radiation source and detector and wherein the presence of a coin or token between the source and the detector causes establishment of a conductive path to earth from a corresponding capacitor.

5. An apparatus according to claim 3 or claim 4, wherein each said corresponding capacitor provides a signal in response to the establishment of said conductive path to trigger inhibiting means for inhibiting insertion of further coins or tokens into the routeway.

6. An apparatus according to claim 5, wherein the inhibiting means comprises a controlled rectifier which is connected in parallel with a coil of a relay for controlling a coin or token entry gate to the routewav 7. An apparatus according to any one of the preceding clau7lS wherein the routeway is a coin routewas through the coinbox of a pay telephone 8. An apparatus according to claim 7, wherein an electrical power supply for the detector means is provided along a telephone conductor pair.

9. An apparatus according to claim 8, wherein one conductor of the pair of and a said sensor adjacent which a coin or token is stationary are connected in a conductive loop to indicate at a remote location the existence of an earth condition caused by the presence of the coin or token blockage.

10. An apparatus as claimed in claim 9, wherein each sensor is connected in series with a respective different value of resistance, and the location of the coin or token in the routeway is indicated by the resistance of said conductive loop.

11. An apparatus according to any one of claims 7 to 10, wherein the sensors are located, respectively, at two or more of the following locations in the coinbox: a coin input runway, a coin acceptance chute, a coin reject chute, and the entrance to a cash box.

12. An apparatus according to claim 11, including a further one of said sensors for detecting when the cash box is partially full.

13. A telephone system in which the direction of current flow in a conductor pair providing communication from a pay telephone having a coin and token freed apparatus to another telephone via a telephone exchange is reversed when communication is established and payment for a call is made at the pay telephone, the coin or token freed apparatus including a coin routeway extending from a coin or token entry to a cashbox and detector means including a plurality of sensors arranged along the routeway for detecting the presence and location of a blockage of coins or tokens, the pay telephone including at least one capacitor which is charged from the conductor pair whilst the current flow is reversed, the presence of a coin or token blockage causing at least one of the sensors to provide a path to earth from the capacitor, and means operative when the current reversal is cancelled to indicate at the exchange, by way of a conductor of a pair, the resistance of a conductive loop which includes the conductor of the pair, and the resistance of which varies with the location of the coin and the one of the sensors which is sensing the presence of the coin to indicate at the exchange the location of the coin or token blockage.

14. Apparatus as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.

15. A system as claimed in claim 13, and substantially as hereinbefore described with reference to the accompanying drawing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (15)

**WARNING** start of CLMS field may overlap end of DESC **. be constructed which does not depend for its operation on a coin or token being conductive For example, if a light or other radiation beam is cut for more than a predetermined period by a falling coin or token, a circuit including the source of the light or other radiation and a detector can function to block the apparatus against the further insertion of coins or tokens, and to provide the remote indication of the position of the arrested coin or token. Another signalling facility which may be added is a further sensor to detect when the cash box is partially, for example threequarters, full. If the three-quarter full con dition is signalled to the exchange, appropriate steps may be taken to have the cash box emptied before it becomes completely full and a blockage occurs. WHAT WE CLAIM IS:
1. A coin and token-freed apparatus including a coin routeway extending from a coin or token entry to a cashbox, and detector means for detecting the presence and location of a blockage of one or more coins or tokens along the routeway, the detector means including a plurality of sensors spaced along the routeway each sensor being arranged to sense the presence of a coin adjacent it and provide an indication of its presence, and monitoring means for monitoring the sensors to determine the presence and location of a stationary coin or token blocking the routeway.
2. An apparatus according to claim 1, including means for inhibiting the operation of the detector means for a period after the insertion of a coin or token sufficient for a coin or token to have passed freely through the routeway.
3. An apparatus according to claim 1 or 2, wherein each sensor comprises a pair of electrical contacts, which when closed by a coin or token establish a conductive path to earth from a corresponding capacitor.
4. An apparatus according to claim 1 or 2, wherein each sensor comprises a radiation source and detector and wherein the presence of a coin or token between the source and the detector causes establishment of a conductive path to earth from a corresponding capacitor.
5. An apparatus according to claim 3 or claim 4, wherein each said corresponding capacitor provides a signal in response to the establishment of said conductive path to trigger inhibiting means for inhibiting insertion of further coins or tokens into the routeway.
6. An apparatus according to claim 5, wherein the inhibiting means comprises a controlled rectifier which is connected in parallel with a coil of a relay for controlling a coin or token entry gate to the routewav
7. An apparatus according to any one of the preceding clau7lS wherein the routeway is a coin routewas through the coinbox of a pay telephone
8. An apparatus according to claim 7, wherein an electrical power supply for the detector means is provided along a telephone conductor pair.
9. An apparatus according to claim 8, wherein one conductor of the pair of and a said sensor adjacent which a coin or token is stationary are connected in a conductive loop to indicate at a remote location the existence of an earth condition caused by the presence of the coin or token blockage.
10. An apparatus as claimed in claim 9, wherein each sensor is connected in series with a respective different value of resistance, and the location of the coin or token in the routeway is indicated by the resistance of said conductive loop.
11. An apparatus according to any one of claims 7 to 10, wherein the sensors are located, respectively, at two or more of the following locations in the coinbox: a coin input runway, a coin acceptance chute, a coin reject chute, and the entrance to a cash box.
12. An apparatus according to claim 11, including a further one of said sensors for detecting when the cash box is partially full.
13. A telephone system in which the direction of current flow in a conductor pair providing communication from a pay telephone having a coin and token freed apparatus to another telephone via a telephone exchange is reversed when communication is established and payment for a call is made at the pay telephone, the coin or token freed apparatus including a coin routeway extending from a coin or token entry to a cashbox and detector means including a plurality of sensors arranged along the routeway for detecting the presence and location of a blockage of coins or tokens, the pay telephone including at least one capacitor which is charged from the conductor pair whilst the current flow is reversed, the presence of a coin or token blockage causing at least one of the sensors to provide a path to earth from the capacitor, and means operative when the current reversal is cancelled to indicate at the exchange, by way of a conductor of a pair, the resistance of a conductive loop which includes the conductor of the pair, and the resistance of which varies with the location of the coin and the one of the sensors which is sensing the presence of the coin to indicate at the exchange the location of the coin or token blockage.
14. Apparatus as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.
15. A system as claimed in claim 13, and substantially as hereinbefore described with reference to the accompanying drawing
GB828576A 1977-05-10 1977-05-10 Coin and token-freed apparatus Expired GB1564723A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB828576A GB1564723A (en) 1977-05-10 1977-05-10 Coin and token-freed apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB828576A GB1564723A (en) 1977-05-10 1977-05-10 Coin and token-freed apparatus

Publications (1)

Publication Number Publication Date
GB1564723A true GB1564723A (en) 1980-04-10

Family

ID=9849588

Family Applications (1)

Application Number Title Priority Date Filing Date
GB828576A Expired GB1564723A (en) 1977-05-10 1977-05-10 Coin and token-freed apparatus

Country Status (1)

Country Link
GB (1) GB1564723A (en)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0924666A2 (en) * 1994-05-03 1999-06-23 Coinstar, Inc. Coupon/voucher dispensing machine and method
US6494776B1 (en) 1992-09-04 2002-12-17 Coinstar, Inc. Coin counter/sorter and coupon/voucher dispensing machine and method
US6602125B2 (en) 2001-05-04 2003-08-05 Coinstar, Inc. Automatic coin input tray for a self-service coin-counting machine
WO2004036510A1 (en) * 2002-10-17 2004-04-29 Vianet Limited Apparatus for detecting a coin jam
US6736251B2 (en) 1992-09-04 2004-05-18 Coinstar, Inc. Coin counter and voucher dispensing machine and method
US7653599B2 (en) 2002-02-15 2010-01-26 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US7865432B2 (en) 2002-02-15 2011-01-04 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US7971699B2 (en) 1992-09-04 2011-07-05 Coinstar, Inc. Coin counter/sorter and coupon/voucher dispensing machine and method
US8033375B2 (en) 2002-02-15 2011-10-11 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US8874467B2 (en) 2011-11-23 2014-10-28 Outerwall Inc Mobile commerce platforms and associated systems and methods for converting consumer coins, cash, and/or other forms of value for use with same
US8967361B2 (en) 2013-02-27 2015-03-03 Outerwall Inc. Coin counting and sorting machines
US9022841B2 (en) 2013-05-08 2015-05-05 Outerwall Inc. Coin counting and/or sorting machines and associated systems and methods
US9036890B2 (en) 2012-06-05 2015-05-19 Outerwall Inc. Optical coin discrimination systems and methods for use with consumer-operated kiosks and the like
US9064268B2 (en) 2010-11-01 2015-06-23 Outerwall Inc. Gift card exchange kiosks and associated methods of use
US9129294B2 (en) 2012-02-06 2015-09-08 Outerwall Inc. Coin counting machines having coupon capabilities, loyalty program capabilities, advertising capabilities, and the like
US9235945B2 (en) 2014-02-10 2016-01-12 Outerwall Inc. Coin input apparatuses and associated methods and systems
US9443367B2 (en) 2014-01-17 2016-09-13 Outerwall Inc. Digital image coin discrimination for use with consumer-operated kiosks and the like

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6758316B2 (en) 1992-09-04 2004-07-06 Coinstar, Inc. Coin counter and voucher dispensing machine and method
US6494776B1 (en) 1992-09-04 2002-12-17 Coinstar, Inc. Coin counter/sorter and coupon/voucher dispensing machine and method
US7971699B2 (en) 1992-09-04 2011-07-05 Coinstar, Inc. Coin counter/sorter and coupon/voucher dispensing machine and method
US7874478B2 (en) 1992-09-04 2011-01-25 Coinstar, Inc. Coin counter and voucher dispensing machine and method
US6736251B2 (en) 1992-09-04 2004-05-18 Coinstar, Inc. Coin counter and voucher dispensing machine and method
EP0924666A3 (en) * 1994-05-03 2000-04-26 Coinstar, Inc. Coupon/voucher dispensing machine and method
US6484863B1 (en) 1994-05-03 2002-11-26 Coinstar Inc. Coin counter/sorter and coupon/voucher dispensing machine and method
EP0924666A2 (en) * 1994-05-03 1999-06-23 Coinstar, Inc. Coupon/voucher dispensing machine and method
US6602125B2 (en) 2001-05-04 2003-08-05 Coinstar, Inc. Automatic coin input tray for a self-service coin-counting machine
US7653599B2 (en) 2002-02-15 2010-01-26 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US7865432B2 (en) 2002-02-15 2011-01-04 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US8332313B2 (en) 2002-02-15 2012-12-11 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US8024272B2 (en) 2002-02-15 2011-09-20 Coinstar, Inc. Methods and systems for exchanging/transferring gift cards
US8033375B2 (en) 2002-02-15 2011-10-11 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
US8229851B2 (en) 2002-02-15 2012-07-24 Coinstar, Inc. Methods and systems for exchanging/transferring gift cards
US8103586B2 (en) 2002-02-15 2012-01-24 Coinstar, Inc. Methods and systems for exchanging and/or transferring various forms of value
WO2004036510A1 (en) * 2002-10-17 2004-04-29 Vianet Limited Apparatus for detecting a coin jam
US9064268B2 (en) 2010-11-01 2015-06-23 Outerwall Inc. Gift card exchange kiosks and associated methods of use
US8874467B2 (en) 2011-11-23 2014-10-28 Outerwall Inc Mobile commerce platforms and associated systems and methods for converting consumer coins, cash, and/or other forms of value for use with same
US9799014B2 (en) 2011-11-23 2017-10-24 Coinstar Asset Holdings, Llc Mobile commerce platforms and associated systems and methods for converting consumer coins, cash, and/or other forms of value for use with same
US9129294B2 (en) 2012-02-06 2015-09-08 Outerwall Inc. Coin counting machines having coupon capabilities, loyalty program capabilities, advertising capabilities, and the like
US9036890B2 (en) 2012-06-05 2015-05-19 Outerwall Inc. Optical coin discrimination systems and methods for use with consumer-operated kiosks and the like
US9594982B2 (en) 2012-06-05 2017-03-14 Coinstar, Llc Optical coin discrimination systems and methods for use with consumer-operated kiosks and the like
US9230381B2 (en) 2013-02-27 2016-01-05 Outerwall Inc. Coin counting and sorting machines
US8967361B2 (en) 2013-02-27 2015-03-03 Outerwall Inc. Coin counting and sorting machines
US9183687B2 (en) 2013-05-08 2015-11-10 Outerwall Inc. Coin counting and/or sorting machines and associated systems and methods
US9022841B2 (en) 2013-05-08 2015-05-05 Outerwall Inc. Coin counting and/or sorting machines and associated systems and methods
US9443367B2 (en) 2014-01-17 2016-09-13 Outerwall Inc. Digital image coin discrimination for use with consumer-operated kiosks and the like
US9235945B2 (en) 2014-02-10 2016-01-12 Outerwall Inc. Coin input apparatuses and associated methods and systems

Similar Documents

Publication Publication Date Title
US3524133A (en) Static state voltage and current monitoring device for electric power cable terminations
US3588611A (en) Transmission line arc detection and location system
US3564524A (en) Fire alarm system having a diode coupled checking circuit means
US3390234A (en) Combination telephone fire alarm and meter reading system
US6421214B1 (en) Arc fault or ground fault detector with self-test feature
US5420740A (en) Ground fault circuit interrupter with immunity to wide band noise
US5329239A (en) Circuit for measuring a capacitance during constant charging and discharging periods
US4935951A (en) Emergency telephone actuated signal light or the like device and method
US5608328A (en) Method and apparatus for pin-pointing faults in electric power lines
AU2005275276B2 (en) Traveling wave based relay protection
EP0084634B1 (en) Electricity meters
EP0455314B1 (en) Remote protection of three phase distribution transformers
CA2127306C (en) Ground fault circuit interrupter incorporating miswiring prevention circuitry
US7443309B2 (en) Self testing ground fault circuit interrupter (GFCI)
KR920010743B1 (en) Coin testing apparatus
AU694273B2 (en) Circuit breaker using bimetal of thermal-magnetic trip to sense current
US3356939A (en) Ground leakage detection apparatus for ungrounded systems including toroidal core detector means
EP0963023A2 (en) Arc fault detector comparing integrated interval to interval filtered load current and circuit breaker incorporating same
CA2589949C (en) Self testing ground fault circuit interrupter (gfci) with end of life (eol) indicator, secondary power supply for eol and self test circuitry, and device for opening line hot wheneol occurs
CA2267005C (en) Test circuit for verifying operation of an arc fault detector
US2339750A (en) Time delay circuit
CA1039140A (en) Coin accepting device
US5621397A (en) Electrical fault detecting device
US4283708A (en) Paper currency acceptor
US4331915A (en) Detection of tampering of kilowatt-hour meters for measuring electrical energy consumption

Legal Events

Date Code Title Description
PS Patent sealed
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 19950510