Pick and Place – Emergency Power Switch

By: Tyler Jones (Manufacturing)

In order for the pick and place machine to have a safe and orderly operation the pick and place needs to incorporate an emergency switch. This should be obviously labeled and easily accessible to the user. If something were to occur as the machine is operating it might take too long to disconnect the microcontroller located in the electronics housing. A large black button clearly labeled “STOP” was added to the exterior of the pick and place. The dimensions of the switch are included below in Figure 1.

 

There are two major power sources that are used in the pick and place machine. The first is a AC to DC power supply that connects the machine to an AC wall or power strip receptacle. Once converted to DC power, bundle of 2 wires feeds the Me Uno Arduino Uno shield. This then powers up both the arduino and shield on top of the arduino. All devices are run from power on the arduino or solenoid switch board circuit. For more information on how to connect the power supply and run the machine please read the instruction manual, or visit the INSTRUCTION MANUAL FOR PICK AND PLACE OPERATION. The other source of power that feeds the machine is the USB connection of +5V from the user’s computer to the pick and place. In testing the pick and place while operating it was found that the +5V is able to still have the code run for the pick and place. It does not however allow the motors, solenoid, or servo motors to run if the +12V power supply is disconnected.

Now by implementing a switch on the +12V line after the AC power has been rectified and converted, the user now has a way to easily stop all motion of the machine. The switch a black colored DPST (Double Pole Single Throw) switch. The switch is wired by splicing the power cord of the DC power supply at the DC end, and routing the power to the switch. In the “OFF” state the switch is open and nothing will run on the machine. In the “ON” state the power will connect to the Me Uno Shield and the machine will run. The Double Pole Switch allows 2 circuits to connect to the switch and the single throw controls the 2 circuits simultaneously. The second circuit is for the other arduino and second power supply if used. A simple diagram on the setup of a DPST switch is shown below in Figure 2