Programmable Logic Controllers?

Question

Can anyone gime me any ideas for something to make using PLCs. I have a limited amount of time to make something and I just don't know what to build.

Answer 1

Using a small nano or micro PLC which has 5or 6 inputs and 3 or 4 outputs you can build:

1.) Differential Sump pump controller which can be used with 1 or 2 pumps, the controller could alternate between the two pumps to even out wear. The second pump could start inconjunction with the first to boost capacity if water levels continue to rise or don't drop after a specific time. You can also add a fault alarm

2.) You can make a state machine to mimic the operation of a washer and or dryer. Think about replacing the mechanical timer in a washer with a PLC

3.) Program a set of traffic lights include the ability for pedestrian crosswalk push buttons and a fault mode where the lights have flashing red and flashing yellow on the cross street.

4.) Game show contestant push buttons. Determine which contestant pressed their button first and lock out others. (Think jepordy). If first contestant gets it wron allow remaing two to compete against each other. Then allow reset for next question.

5.) Simulate a boiler control. The operation of a boiler needs to properly sequence the starting of a fire in the furnace in responce to a call for steam. The furnace need to be purged, a fuel pump need to start and be up to pressure a fuel oil valve need to open an ignitor need to fire then a flame must be detected within a limited time. This requires programming a series of interlocks and timed sequences in addition the boiler needs to be monitored for water level hi/lo and steam pressure Hi/lo

6.) Program an electronic lock. Input push buttons must be pressed in a particular sequence within a given time in order to allow the output to open a lock. Limit the attemps to 3 and limit the time the keys must be pressed (consider switch debouncing as well) . If user fails to enter proper code sound an alarm and or lock out further attemps for a period of time.

7.) Using a model rail road engine and several feet of straight track, make a toy RR engine travel back and forth on the straight track without running off either end. You will need proximity detection and a means of switching polarity to the engine as well as stopping. Consider using a DPDT relay or use the output on the PLC to function as DPDT



Do follow up and let us known what you decide on building and how you make out with your project.....

Answer 2

You haven't given me much to go on regarding budget or what you are interested in, but I suggest a controller for a light show.

With an advanced control system, your neighbours may have more lights than you this Christmas, but you could dazzle onlookers with your sophistocated sequencing and timing. Maybe even syncronise the display to music.

Answer 3

I believe you have to use software to build a circuit, then upload the circuit onto the board making sure to assign inputs and outputs to actual positions on the board in your circuit