Simple electronic combination lock - Uses one common CMOS chip and pushbuttons to provides nice features and high security HOME

This Electronic Lock circuit is not only simple but it is also very good. It can easily be configured to provide either momentary or continuous output. Key sequences of up to 9 digits are possible. You can pre-enter part of the combination and then have someone else enter the last few digits at a later time allowing for one-time access. This circuit has good debounce but there are some REALLY crappy switches out there so please look for types with spring or snap contacts. For better security or for a mad-scientist look you might use unlabelled pushbuttons arranged in some unusual shape.

Simple CMOS combination lock

I do not gaurantee the accuracy or safety of any information herein.
This is only a graphic due to spam     HOME     Valid HTML 3.2!
Do not experiment with or build any of the above circuits.