Lab Team 4 Week 13

Chris Week 13

        1.     Provide the updated computer drawing for your individual RG setup.

    2.     Explain your setup.

      My setup all starts with a photosensor. While this sensor is in its cardboard holder that I made for it, it has a resistance value of about 4 to 5 kilo ohms. Once the light from Kevin's circuit hits it, the resistance value drops to about 300 ohms, allowing a stronger current to run through it. This strong current then powers my 555 timer, which starts up my digital display part of the circuit. This circuit is set up very similar to our circuit from earlier this semester. The only difference is that I am using the photosensor instead of the force sensor to start it, and at the end of the circuit, I have an AND gate that will ultimately turn on a motor. 

          To power the motor, I will use an opamp that will amplify the signal from the AND gate, then activating a transistor, giving the motor enough current to spin the motor and knock over dominos. Once the dominos start to fall, a golf ball will be set into motion that will eventually start the next circuit. Also, a domino will activate a mousetrap that will hopefully pull the ground wire of my motor, turning it off. 

   3.     Provide photos of the circuit and setup.

This is a close up photo of the digital display part of the circuit

Here is a photo of my entire circuit

This shows how my photosensor is poking through a cardboard stand

  4.     Provide at least 2 new videos of your setup in action, one being a failed attempt.

This video shows my circuit properly working

This video is close to working, but I had wired the AND gate incorrectly, and the motor and LED only come on at 9, not 5 and 7.

 5.     What failures did you have? How did you overcome them?

      For this week, my main challenge was to properly power my motor. I realized that a transistor was necessary to power my motor, and once I came to that conclusion, it was relatively smooth sailing. My next big challenge that I will face is activating the circuit after mine. I originally intended on making a catapult setup, but I decided to go a different route. I will use dominoes to set a golf ball in motion, down a ramp, and into a switch, starting the next circuit. That is the plan at least. I also need to solidify the way I will turn off my motor once the dominoes get knocked over. I will use a mousetrap to do so, I just need to find the best way to use the mousetrap's motion to disconnect the ground wire. 

Kevin Week 13

  1.     Provide the updated computer drawing for your individual RG setup.

Updated Schematic with Addition of Force Sensor and Ohm-Meter

A Block Diagram I made in MS Paint showing the basic operation of my Circuit.

    2.     Explain your setup.

   Explanation  From Last Week's Blog:
   (See week 12 Post for Larger Text)

    

    My Circuit consists of two main parts separated by a control relay.

     The First half of circuit provides voltage to the relay's coil, consists of: 

     4 solar panels, 

     1 Op-Amp IC chip

     2 Resistors (68 and 350 Ohms)

     1 Toggle Switch

     A 12 Volt Power Supply   

     

     The 4 Solar panels are connected in series and provide an input voltage to the Op-Amp.  The Op-Amp is setup in non-inverting  configuration and connected to a 12 VDC power supply through a simple on/off toggle switch along with two resistors.  This configuration provides an approximate voltage 6x the input from the solar panels to the coil of the relay.

    When the Relay is actuated it provides voltage from a second separate 12 VDC power supply to a single pole double throw switch.  This switch has one input and two outputs, with the input being spring loaded to it's "normally closed" contact when no pressure is applied.

    The switch's normally closed contact is connected to a 12VDC pump which is capable of circulating 200 Liters of water per hour.  While the "Normally Open" contacts ar connected to a 12VDC 35W Halogen Flood Light.

     

    The switch itself rests between two spring loaded plates, when enough pressure is applied to the upper plate to overcome the spring's tension the switch actuates and breaks the "normally closed" contact while simultaneously connecting the input to the "normally open" contact.

    The Circuit is actuated by providing light to the solar panels which send a 1.5-2 VDC to the Op-Amp.  It the the toggle switch in in the ON position the Op_amp then actuates the control relay sending power to our pressure switch.  That power then activates the water pump pumping water from a reservoir into a container resting on top of the pressure plate.  As the container fills the increased weight on the pressure plate overcomes the plates' spring tension and compresses the pressure switch into the normally opened position.  This cuts off the voltage the pump, stopping the flow of water, and redirects it to the floodlight.  Light from the Floodlight is then used as a trigger for Chris's circuit (See Chris's Blog Entry for a full breakdown of his circuit.)  

    New Additions Week 13:

    In order to give my setup an extra visual component for spectators to look at as my bottle fills I added a force Sensor connected to an Ohm-meter to my pressure plate setup.  The Force sensor starts reading OL when my water bottle is empty but as it fills the resistance drops steadily to approximately 1.6 Kilo-Ohms at which point the pressure switch activates and cuts off the pump as described above.  

   3.     Provide photos of the circuit and setup.

Solar Panel Array and Breadboard portion of my circuit.  Not much to look at but it gets the job done.

A Photo of the inner workings of my pressure plate the diagonal cutters act as a spring providing resistance and only allowing the  switch (seem at the top of the photo) to actuate after sufficient has weight has been applied to the plate to compress the pliers.

A Picture of my pressure fully assembled.

4.     Provide at least 2 new videos of your setup in action, one being a failed attempt.

See Step 7 Under Group For Success Video

Failure to Launch

 5.     What failures did you have? How did you overcome them?

  My biggest problems this week involved my solar panels and Op-Amp.  The Op-Amp has been finicky ever since I transported the circuit from my home to the lab.  I have replaced most of the jumpers from our kit with heavy duty hook-up wire to insure a good connection and while the issue has improved I am still having intermittent problems with the Op-Amp Circuit.  

  

  As for the solar panels I believe they suffer from a serious design flaw, specifically their tin-foil like "Lead"  Even the slight movements caused by assembling/disassembling my circuity for storage and transport have caused the alligator connected to the solar panels to damage the leads leading to a lessened output.  I am considering replacing them with a more durable Solar Panel that I use to charge my phone while camping if I can find a good way to adapt it to my circuit without any risk of damage. 

     

Lab Team 4 Week 13 Combined Portion      

     

      6.     Group task: Explain your group RG setup.

This video gives the explanation of how our group RG setup works

      7.     Group task: Video of a test run of your group RG.

This video shows our group RG working

This video shows our group RG not working