This is a project which is very useful for the working system in the banks.  When money is withdrawn from the bank a token is handed over to the person which is deposited to the cashier and money is received.  There is possibility of this token going to be a wrong person and he can misuse the token.  With the help of this project a secret message is conveyed to the cashier that proper person is taking out the amount.  As per the necessity there may be many uses of this project.


This project has been developed and tested O.K. in our TV Engineers Technical Lab.  The components and PCB used in the projects published in our books are available for sale at resonable price.

Two IC 4543 and one IC CD4017 has been used in this project.  Beside this four no. transister BC148 have been also used.  IC 4543 works as one BCD to Seven Segments Latch/Decoder.  IC CD 4017 is a decade counter and this is a digital IC.  Pin no. 16 is its supply pin and pin no. 14 is the trigger pin.  There are 10 output pins and these are 1, 2, 3, 4, 5, 6, 7, 9, 10 and 11 respectively. Pin no. 15 is a reset pin. In this circuit BCD [Binary Coded Decibel] output is obtained through the diodes which is given to the pin no. 5, 3, 2 and 4 of the IC 4543 [2 numbers] and latch pin is connected to the pin no. 2 and 3 of the IC CD4017.  Pin no. 2 and 3 are the output pins of IC CD4017.  At the output of the transister BC148, a FND is connected which is kept blank. This transister is connected to the pin no. 7 of the IC 4543. It means that none of the segment of FND glows. By pressing any switch on the matrix, information connected with this reaches to the input of IC 4543 and the positive going pulse reaching at the trigger pin of the IC 4017 triggers it and this pulse after reaching there increases the output one step more and transister connected to the output gives  negative going pulse on the pin no. 1 [Latch Pin] of IC 4543.  Due to this the BCD on the input gets stored in the IC and displayed on the FND.  If a negative going pulse is given to the pin no.15 of the IC CD4017 and then it resets and makes the blank pin no. 7 of IC 4543 low.  Due to this FND goes OFF and display is cleared.  Now the display is ready for the next number. The input pin of the switch D is connected to the positive supply and a transister connected at the output pin drives the circuit.  When there are positive voltage on pin no.10 the switch D Latches and relay operates,  if A, B, C, D, E connected in series are not put ON before the discharge of the condenser.  The rest of the switch are connected  in the parallel of the capacitor and along with the reset besides A, B, C, D. On pressing wrong switch capacitor will be discharged and switches are resets in order.


  1. Do not touch CMOS IC with hands because human body get charged due to anti-static charge and CMOS IC may be spoiled.


PCB [CODE 6TP04]=1


IC 4543=2, IC 4017 =1, IC 7805=1

FND [ Common Cathode ]=2

BC547=4, IN4148=21


470E=2, 4K7 =5, 10K =6, 330E=14


1mfd/25V =2, 0.1/50V =2



Cabinet =1