The following is a "Bank" circuit that I$\text{'}$m using as part of a virtual vending machine in Logisim Evolution. Here's how it works:

A person can insert a nickel $($In$5),$ a dime $($In$10),$ and a quarter $($In$25)$ into the "bank". There's an enabler $($Ena$)$ that turns the Priority Encoder on and a reset $($Rst$)$ button that resets the D Flip$-$Flop back to $0.$ If you insert a nickel $($In$5),$ the Priority Encoder sends a signal to the multiplexer, which then sends a $"05"$ number out to the adder, in which the adder is then fed into the D Flip$-$Flop $($The D Flip$-$Flop is activated everytime a coin is inserted$).$ The Flip$-$Flop adds a nickel to its contents which is output as the accumulated amount $($OutAcc$)$ and finally fed back into the adder, so if you add another nickel, the adder has $10$ cents instead of just $5.$

Unfortunatley, there is an issue with the circuit that I$\text{'}$m dealing with. I need the coin input to stop once $75$ cents is reached but it is not working. Now, customers can continue depositing coins into the machine even after reaching $75$ cents. How do I correct this issue?