GB2313694A

GB2313694A - Coin exchange unit

Info

Publication number: GB2313694A
Application number: GB9611179A
Authority: GB
Inventors: Farrokh Shirvani
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-05-29
Filing date: 1996-05-29
Publication date: 1997-12-03
Also published as: GB9611179D0

Abstract

An electronic exchange unit comprises a microcontroller and, when installed inside equipment with the facilities to accept and pay out coins and tokens for the purpose of a service, or for the purpose of amusement, diverts the pay out of the equipment from one type of coin or token to another type of coin, or a combination of up to three different coins that the equipment has the facilities for dispensing. The device is capable of receiving input pulses of either polarity and duration between 20 to 500 milliseconds. The generated output pulses have the same period as the input pulse and can also be selected to be of either polarity. These outputs are connected directly to the machines power switching devices to control the dispense of exchanged coins. Up to 256 different pay out combinations can be selected.

Description

UNIVERSAL COIN EXCHANGE UNIT The universal coin exchange unit is an electronic device that when installed inside an equipment with the facilities to accept and pay out coins and tokens, it diverts the pay out of the equipment from one type of coin or token to another type of coin, or a combination of up to three different coins, that the equipment has the facilities for dispensing.

There are a large variety of machines that accept coins or tokens or both for providing a service, or for amusement, like coin changing machines, amusement with pay machines, food dispensing machines, car park ticket machines and many more. These machines accept and pay out coins or tokens or both. But due to changes in the currency or price increase or a type of coin going out of circulation, these machines require costly upgrading and in some cases can become obsolete.

The universal coin exchange unit is a Microcontroller based electronic device that when installed inside a coin or token operated machine, provides an easy and cost effective solution for modifying the pay out of the machine. The circuit diagram of this unit is shown in figure 1. All functions of this unit are controlled by software written in assembly language that is held in the Microcontroller's internal non volatile memory. The universal coin exchange unit monitors and holds back the pay out of one type of coin or token and instead diverts the withheld amount to be paid in other combinations of coins, that the machine has the facility for dispensing. In these machines coins and tokens are dispensed by means of electromechanical devices called solenoids. Electronic power switching devices such as Triacs and power Transistors are used for supplying power to these solenoids.

Also at the heart of every coin or token operated machine there is a main processing unit that generates electrical pulses of approximately 100 milliseconds, which are fed to the power switching devices. The polarity and duration of these pulses vary from machine to machine.

To inhibit the dispense of one type of coin or token in a machine, the link from the machine's main processing unit to its related power device is cut and then fed into the input of the universal coin exchange unit.

The universal coin exchange unit can accept input pulses of either polarity by means of a three way link selector LK10, shown in figure l. For machines that generate negative pulses a shorting link is used to short pins 1 and 2 of the LKl0. And for machines generating positive pulses pins 2 and 3 are linked. Therefore a negative pulse is always received on pin 3 of the Microcontroller for an input pulse of either polarity.

The universal coin exchange unit can accept input pulses with duration between 20 to 500 milliseconds. The period of received pulses on pin 3 of the Microcontro11er is measured and is then used to generate output pulses with the same period.

The validity of each pulse received by the Microcontroller is also checked. At the start of each pulse the software monitors the input for change of level from Low to High. If a change is detected, the pulse will be rejected. The time period during which this test is carried out can be selected between l0 miüiseconds, if link LK9 is present. Or 20 milliseconds if link LK9 is absent. Hence spurious electrical noise spikes which are much shorter than 10 milliseconds in duration are rejected.

After the initial test an internal timer is triggered to start. The low to high transition of the input, which indicates the end of the pulse stops the timer. By adding the measured time obtained from the timer to the initial test time the duration of the pulse is calculated.

Also at the end of the pulse, an internal register holding the number of pulses is incremented by one and then the internal timer is initialised to time a period of approximately five times the duration of the received pulse. During this period if another pulse is received at the input, the timer is re-initialised to start from zero again. Therefore as long as regular pulses are received at the input, the timer can not finish its pre-programmed period.

Eventually when no more pulses are received at the input, the timer is allowed to finish its period. At the end of this period the universal coin exchange unit generates the appropriate number of pulses on one or two or all of its three outputs, according to the programming configuration of the unit's selector links shown in table 1 of figure 2. This table only shows 16 programmes out of the total of 256 different pay out combinations, some of which are reserved for European currencies.

If the universal coin exchange unit is programmed to pay in more than one type of coin, for example to pay Pound coins on output 1 and 10 Pence coins on output 2, from input pulses of 20 Pence in value as programme (h) of table 1, as soon as a total is reached that can be paid, an appropriate pulse is generated even before the period of five times the pulse duration of the internal timer is over.

In this example if twelve pulses of 20 Pence value are received at the input, making the total to the value of two Pounds and forty Pence. Instead of generating two pulses on output 1 for dispensing two Pound coins and four pulses on output 2 for dispensing four 10 Pence coins after the end of the twelfth pulse, the universal coin exchange unit outputs one pulse on its output 1 after the fifth received input pulse, then it generates a second pulse on the same output after the tenth received pulse. And then after the final twelfth pulse it outputs four pulses on its output 2 as shown in the waveform diagram of figure 3. This is important in a coin or token operated machine with a digital display that counts down as the coins or tokens are dispensed. By this the pay out will be at even intervals during the count down, and not all at the end when the display has reached zero.

The pulses generated at the three outputs of the universal coin exchange unit can also be of positive or negative type. A three way link selector is provided for each output to control this. A short between pins 1 and 2 of the link produces a negative pulse in the form of an open Collector NPN transistor driver. And a short between pins 2 and 3 of the link produces a positive pulse driven by an Emitter Follower NPN transistor. These outputs are used for the dispense of exchanged coins and are directly connected to the Base or the Gate of the power switching Transistors or Triacs which already exist in coin or token operated machines.

The universal coin exchange unit operates from a 5 Volts dc supply obtained from the machine it is installed in. The installation instructions or machine's service manual provide the information about the locations of the 5 Volts supply and the power switching devices.

Claims

1. An electronic universal coin exchange device that when incorporated inside an equipment with the facilities to accept and pay out coins and tokens for the purpose of a service, or for the purpose of amusement, it diverts the pay out of the equipment from one type of coin or token to another type of coin or a combination of up to three different coins that the equipment has the facilities for dispensing.

2. An electronic universal coin exchange device as claimed in Claim 1 wherein the input pulse to the device can be either of negative low going, or positive high going type.

3. An electronic universal coin exchange device as claimed in Claim 1 and Claim 2, wherein the duration of the input pulse cab be in the range of 20 to 500 milliseconds.

4. An electronic universal coin exchange device as claimed in Claim 1, Claim 2 or Claim 3, wherein up to three independent outputs can generate pulses of either polarities.

5. An electronic universal coin exchange device as claimed in Claim 4 wherein the period of output pulse is the same as the measured period of input pulse.

6. An electronic universal coin exchange device as claimed in any preceding claim, wherein up to 256 combinations of coin exchange can be programmed.