Note: Descriptions are shown in the official language in which they were submitted.
12S7363
The present invention relates to metering and more
particularly relates to metering involving the use of meters
which respond mechanically or electrically to electrical metering
pulses.
There are many applications where meters are utilised to
read electrical metering pulses. One specific example is the use
of meters present within an amusement with prizes or gaming
machine such as a "fruit machine". Such meters are used to
record the number of games played and the number of prizes
awarded. Typically there will be a bank of meters, each metering
one specific occurrence, each meter being triggered by means of
an electrical pulse supplied to the meter by a meter pulse
generator.
It has been known for dishonest operatives of such machines
to dlsconnect the meters for a period of time. This enables the
dlshonest operatives to remove, from the cash or token tray
within the machine, a number of coins or tokens, and if the
meters are only disconnected for a relatively short period of
tlme lt ls possible that the owner of the machine will not
actually realize that anything is a miss.
Meters of this general type are also used in other positions
where disconnection of the meter by dishonest or fraudulent
personnel is not desirable. For example, such meters are present
in many photocopying machines, especially where such machines are
leased to the operator, who is then charged on small fee for each
copy taken on the machlne.
The present lnvention seeks to obviate or reduce the
problems experienced with prior metering arrangements.
According to this invention there is provided a meter
monitoring apparatus adapted to monitor the operation of meters
which are actuated in response to electrical pulses from a pulse
generator, the arrangement comprising means defining a current
path extending to said meters through which current will flow
where any one of the meters is actuated, means responsive to a
flow of current in said current path, and an alarm device adapted
to receive a signal from said responsive means and to be provided
with a pulse simultaneously with a pulse being provided to any
meter, the alarm device being actuated in response to the
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reception of one or more such pulses without the corresponding
said signal or signals being received.
Preferably said responsive means comprise means to establish
a potential difference when a current flows through said current
path.
Conveniently the means for establishing the potential
difference comprises a resistor or resistive element present in
the current flow path.
Preferably said resistor or resistive element comprises one
or more diodes in the current flow path.
Conveniently a transistor switch is provided which is
switched on when said potential difference is established, the
switching on of said transistor switch providing a signal for
said alarm circuit.
Advantageously the output of the transistor switch is
utilised to control a second transistor switch, operation of the
second transistor switch substantially altering a potential which
is normally applied to one input of the alarm circuit.
According to another aspect of the invention there is
provided a meter monitoring apparatus said apparatus being
adapted for use w~th a plurality of meters each adapted to
- receive metering pulses from a meter pulse generator, the meters
being connected in parallel between the meter pulse generator and
a potential supply line, there being a pair of diodes connected
;~ 25 in series between the supply line and said meters, a transistor
switch being connected across said diodes being adapted to be
switched on when any one of the meters is pulsed and current
flows through said diodes the transistor switch, when switched
on, applying potential to a second transistor switch to switch
the second transistor switch on, the second transistor switch
being connected to an input of an alarm circuit in such a way
that when the transistor switch is switched on the input of the
alarm circuit is connected to a line carrying a first potential,
the said input to the alarm circuit also being connected by means; 35 of a resistive path to a line carrying a second potential so that
when the second transistor switch is not switched on the input to
the alarm is provided with the second potential and when the
~, second transistor switch is switched on the input of the alarm is
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provided with the first potential, the alarm also being connectedto the meter pulse generator to receive a pulse whenever a
metering pulse is supplied to a meter, the alarm circuit being
adapted to respond whenever it receives one or more pulses from
the meter pulse generator and the potential on said input is not
altered to be said first potential.
In order that the invention may be more readily understood,
and so that further features thereof may be appreciated, the
invention will now be described, by way of example with reference
to the accompanying drawing, which is a circuit diagram, partly
in block diagrammatic form, of a metering arrangement in
accordance with the present invention.
Referring to drawing, a metering arrangement in accordance
wlth the invention is lntended to be utilised in connection with
an apparatus having a meter pulse generator I which supplies
pul~es to one or more meters 2, 2A, etc. Only two meters are
shown in the accompanying drawing but it is to be understood that
any approprlate numbers of meters may be provided, the meters
belng arranged in parallel.
The meter pulse generator is of the type which provides a
;~ signal of zero volts i.s. an "earth" signal on an input to a
meter when the meter is to be "clocked" or advanced by one count.
Meters of this type are well known and thus do not warrant
descrlption here.
It can be seen, in the accompanying drawing, that the meters
2, 2A, etc are connected in parallel to a meter supply 3 of +12V
through two IN4001 diodes 4, 5 which are connected in series. It
will thus be appreciated that when the meter 2 is to be clocked,
for example, the meter pulse generator I will earth (or apply a
potential of zero volts to the appropriate lead connected to the
relevant meter and a pulse of current will flow from the 12V rail
3, through the diodes 4, 5 and through the meter thus causing the
meter to clock.
A BC327 PNP transistor 6 is provided, the base of which is 35 connected, by means of a lOK resistance 7 to a point between the
second diode 5 and the first of the meters 2, 2A etc. The
emitter of the transistor 6 is connected to the 12V rail 3, and
emitter of the transistor is connected to a IK resistance 8.
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When any one of the meters is clocked and current flows from the
12V rail 3, through the diodes 4, 5 and the meter 2 to the meter
pulse generator I, there will be a potential drop across the
diodes 4, 5. Thus a potential of approximately IIV is applied to
the base of the transistor 6 whilst a potential of 12V is applied
to the emitter. The transistor 6 is so biased that when this
occurs the transistor is switched on. When the transistor 6 is
switched on a +12V signal is applied, through the resistor 8, to
the base of a second transistor 9, which is an NPN type
translstor BC337. The base of the transistor 9 is connected by
means of IK reslstor 10 to an earth rall II, and the emitter of
the tran#lstor 9 18 also connected to earth rail II. The
connector of the translstor 9 is connected by means of IK
resistor 12 to a +5V supply rall 13 and the node between the
reslstor 12 and the collector of the transistor 9 is connected by
means of a lead 14 to an alarm circuit 15.
It wlll be understood that, under normal conditions, when
the translstor 9 ls "off" a +5V slgnal wlll be present on the
lead 14. However, when the above descrlbed pulse is applied to
the base of the transistor 9, the translstor 9 ls switched on,
and consequently a substantlally zero volt OV signal is present
on the lead 14 and ls supplied to the "alarm" circult 15.
It wlll thus be appreciated that, as a consequence of any
one of the meters 2, 2A etc been clocked by the meter pulse
generator, a correspondlng pulse wlll be applled, as a
consequence of meter operation, to the alarm circuit 15. At the
end of the meter-clocking operation the circuit will, of course,
return to its inltial or quiescent condltion.
It wlll be noted that a lead 16 extends from the meter pulse
generator to the alarm clrcuit 15. Whenever the meter pulse
generator generates a pulse to clock a meter, it simultaneously
~; generates a pulse which is supplied to the lead 16 and to the
alarm circuit.
The alarm circuit 15 is adapted so that if it receives a
pulse on the line 16 and does not receive a corresponding pulse
on the line 14, (in other words if the meter pulse generator
generates a metering pulse, but none of the meters is observed to
operate) the alarm circuit will respond. Depending upon the
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location of the equipment the alarm circuit could respond in many
different ways. For example, if the described metering
arrangement is present in an amusement with prizes machine or a
gaming machine, the alarm circuit may merely return any coins or
tokens inserted into the machine to institute play and may
prevent further operation of the machine. If the machine is
provided with a CRT display or some other controllable display, a
message can be displayed indicating that the machine is
temporarily out of order. If the described arrangement is in a
photocopying machine the alarm circuit, when actuated, may render
the machlne inoperative. Alternatively the alarm circuit may
cau8e an alarm bell or some other audible or visible alarm to be
actuated, if thls is appropriate in the circumstances surrounding
the use of the described device. It will be appreciated that the
alarm circuit may also control various other functions.
It will be appreciated that if a person tampers with meters
or disconnect~ the meters so that they will not operate, the
alarm circuit will be actuated as soon as the first metering
pulse is generated which does not actually "clock" a meter.
Also, if a meter suffers a mechanical failure, and thus does not
operate, again the alarm circuit will be actuated.
In a modified version of the invention the alarm circuit
will only be triggered when two or three successive pulses are
received from the meter pulse generator without a corresponding
pulse being received on the line 16 from the meter operation
monitoring circuit. This will avoid the problems that may arise
if a particular meter fails to operate from time to time due to a
slight mechanical fault, or if there are other "minor glitches"
in the system.
