# Design and Fabrication Of Coin Separator Machine – Coin Sorting Machine

INTRODUCTION
Counting of coins is a tedious task when coin collections are large. Say for example, in Banks, Temples, bus depots, shops, etc., they are spending a lot of time and strain for counting their collections. Usually the method they are adopting is first to separate the coins in each denomination and then count the total in each denomination. Finally the totals of each denomination are added to get the grand total. From this we can understand that separating into denominations is a tedious work. So it will be very much helpful to them if a device can be used to separate the coins in denominations. It will be relatively easier to attach provisions for automatic counting once the coins are separated.

COINS AND THEIR PARAMETERS

The following four parameters were considered for sorting of the coins:
Diameter/distance
Thickness
Weight
Magnetic property

Diameter/distance
If the shape of the coin is circular then its diameter itself is the parameter. But all the coins are not circular in shape so in case of coins which are not circular in shape, ‘distance’ is considered as the parameter. The term distance refers to either corner to corner distance or flat to flat distance. For example as shown in figure1 for a 5 paise coin which is square in shape, ‘d1’ is the corner to corner to distance while ‘d’ is the flat to flat distance. The distance parameter for 10 paise, 20 paise and 100 paise coins are as shown in the figure .

Thickness
For most of the edge has more thickness than the inside surface. The maximum thicknesses of the coins were measured using a vernier caliper with a least count of 0.01 mm and the values noted in table 1.

Weight

Weight of the coin is also an important parameter in sorting out the coins. Hence the weight of each coin has been determined using an electronic weighing machine having readability up to 0.01gmf. The coins were put one by one on the pan and the corresponding weights are obtained on an optical read-out and values noted in table 1.

Magnetic property
If the coins of one denomination are magnetic while the coins of another denomination are non-magnetic, these two denominations can easily be separated by using this parameter.
In each denomination 10 coins were taken at random and on each coin measurement of their magnetic property made at more than one place and it was noted in table 1, whether the coins were magnetic or non-magnetic.

## Application of coin parameters for separating the coins.

solution using Diameter/Distance
In this method a circular template with a number of holes, in ascending order of diameter in anti-clockwise direction, is held stationary. A thin circular plate which is referred to as rotating arm has holes to accommodate a coin having maximum diameter.
The rotating arm dimensions should be so designed that only one coin is carried in each of the arm holes. When the coin comes over the corresponding hole it falls through that hole.