-Design Criteria-
ACME Fireplace Company hired me to redesign a residential gas fireplace. Their current burners are equipped with four sensors that detect a flame (logic 1). As long as a flame is present, the fireplace will continue to supply gas. This design has faults and a redesign is necessary.
For the redesign, three of the four circuits must sense gas, or an emergency cut-off switch will kill the gas feed to the fireplace.
Additionally, a second fault indicator will be included for a service technician to help troubleshoot future problems. As long as all four sensors agree, the fault circuit will remain off. If the fault sensor circuit disagrees in any way, the fault indicator will be tripped.
For the redesign, three of the four circuits must sense gas, or an emergency cut-off switch will kill the gas feed to the fireplace.
Additionally, a second fault indicator will be included for a service technician to help troubleshoot future problems. As long as all four sensors agree, the fault circuit will remain off. If the fault sensor circuit disagrees in any way, the fault indicator will be tripped.
-Design Constraints-
- The Karnaugh mapping technique must be used to obtain the simplified logicexpression for both outputs.
- The circuit that controls the emergency cut-off valve must be implementedusing only 74LS00 two-input NAND gates.
- The circuit for the possible faulty sensor indicator must be implemented usingonly 74LS02 two-input NOR gates.
-Procedure-
-errors-
I did not experience any errors in this project, but that was mainly because I did not have to breadboard this activity. Creating truth tables, K-Maps, logic expressions, and schematics are relatively easy. Likewise, breadboarding is also easy, but the chances for random human errors are much greater when breadboarding.