Looking for information about digital code lock circuit

[cheggers]

circuit help-4017

Hey people, i have chosen a project for my college course but the info with the circuit is bare minimum, was wondering if anyone has built this circuit before, It's a deigital code lock, quite a simple circuit but i cant say by looking at it if it woul work etc. wondering if anyone had any info on the circuit for me?, Thanks a lot, Cheggers.

 

[IanP]

Re: Circuit Help

Could you post your circuit?
Or, would you like someone to suggest you a different design?

 

[cheggers]

Re: Circuit Help

**broken link removed**

sorry forgot to post it! oops, well another design would be ok to if its a better one, any sugesions! Thanks

 

[gidimiz]

Re: Circuit Help

Hi,

From reading the data sheet of the 4017
**broken link removed**, you can see on page 4 that every time the Clock is pressed, the signal moves forwared from pin pin to the next.
From looking at the design and the from what we saw in the data sheet, you can understand that if you press PBS A 6 times, the firt CMOS4017 will move to location Q6. Only then you can press PBS B 3 times to it will move to Q3 and so on. If you wont press PBS A 6 times, it wont move to the correct out put thus the AND gate will have logic 0 and one leg and if you press PBS B, nothing will happen. All the rest of the ocmponantes are needed so the cicuit will work fine without any gliches.

Here is what the guy that built it wrote, maybe it will be more clear:

The circuit above above makes use of the CMOS 4017 decade counter IC. Each depression of a switch steps the output through 0 - 9. By coupling the output via an AND gate to the next IC, a predefined code has to be input to create the output. Each PBS switch is debounced by two gates of a CMOS4001 quad 2-input NOR gate. This ensures a clean pulse to the input of each CMOS 4017 counter. Only when the correct number of presses at PBS A will allow PBS B to become active. This is similar for PBS C and PBS D. At IC4, PBS D must be pressed 7 times. Then PBS C is again pressed 7 times, stepping from output 1 to output 8. The AND gate formed around CMOS4081 then goes high, lighting the LED. The Reset switch can be pressed at any time. Power on reset is provided by the 100n capacitor near the reset switch

If you have any cpecific question, ask them and we shell answer.

One more thing, maybe you sould try to build a diffrent circuit. The guy how built it said that There was a small spark, and puff of smoke before all this chips were cooked!
Try:
http://www.discovercircuits.com/list.htm

Good luck.

 

[cheggers]

Re: Circuit Help

Thanks mate! I have tried to contruct the circuit on software called livewire so i can have a pcb layout of the circuit but i cant seem to get it to work on there. Is there anyone who has already made this circuit on livewire or anyone that could try and construct it on livewire, Would be very very greatful!!

Cheggers

 

[Sikander Khwaja]

Circuit Help

Dear fellow why dont u try an easy one ( software )
like "pcb 123" It has very simple tools & can be easily downloadable from net