Does anybody have any diagrams / construction notes to build a coin sorter.

I am trying to build one that uses a 2 digit 7-segment display to output the coin count, counting british coins (1,2,5,10,20 pence coins). 1p and 10p aren't an issue its making the counts for the others. I thought of using 5 different coins slots for the different coins and then triggering the clock input on a 4026 7segment display driver via a microswitch in the coin slot. Also it would be beneficial to be able to switch the display between coin slots, so as to save on the parts used.

 

Any ideas would be gratefully recieved

WSMM