Purpose: to Build a Circuit That Determines How the Temperature Changes As Altitude Increases

CricketSat Assembly

Purpose: To build a circuit that determines how the temperature changes as altitude increases.

Materials: Multimeter, CricketSat component pack, 9 volt battery, soldering iron, solder

Procedure:

1. Identify and organize all components in your CricketSat pack using the identify and organize chart.

2. Test the battery voltage using a multimeter. The voltage should range between 8.9V – 9.0V. If the voltage on the battery is less than 8.9V replace your battery with a fresh battery. Test the fresh battery to make sure it is within the 8.9V – 9.0V range.

Measured battery voltage: ______Volts

3. Insert the 8 pin socket in the PCB with the notch towards the battery terminals as shown in the diagram. Solder the socket into the PCB.(YOU CAN MESS UP ON THIS! – pay attention to the notch)

4. Solder the switch into the PCB in the correct location. The switch notch should face out of the board as shown in the diagram.

5. Insert the LED into the correct location. Note: LED stands for light emitting diode. A diode is a polarized component – this means one side is + positive and the other side is – negative. The long lead is positive and the short lead is negative. Insert the positive lead into the square via and the negative leads into the circle via.

6. Insert and solder the2.7 k resistor, it is R1.

7. Insert and solder the two 330  resistors, they are R3,and R4.

8. Insert and solder the three .1 F capacitors, they are C1, C2 and C5.

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9. Insert and solder the .033 F capacitor, it is C3.

10. Insert and solder the 1 Fcapacitor , it is C4.

11. Insert and the 4 pin socket in the correct location. Orientation does not matter with this socket.

12. Now we will be preparing the Thermistor to be soldered to the PCB. The Thermistor could be soldered directly to the PCB but that would make it very difficult to test. So we connect the two leads of the Thermistor to long wires and connect the wires to the PCB. This allows us to insert the Thermistor into a cold or hot water bath without immersing the PCB (which would destroy it). The wires you received to connect to the Thermistor are twisted. We want to leave the wires twisted mostly. Untwist about an inch of the wires at one end. Strip each wire about 2 centimeters using your wire strippers. Connect by twisting each wire to the Thermistor leads. Now we want to make sure there is a good electrical connection between the wire leads and the Thermistor leads so make sure they are twisted tightly together. We will take an additional measure to make sure they stay together. Use the small diameter heat shrinks and slide each over the twisted leads. Use the heat from your soldering irons to shrink the plastic around the leads.

13. To add another level of stability to the Thermistor we will use the large diameter heat shrink to cover both leads and heat shrink them together. DO NOT COVER THE THERMISTOR!It will not work properly with heat shrink around it.

14. Now we need to connect the Thermistor wires to the PCB. Untwist the other end of the wires about an inch. Strip that end of the wires about 2 centimeters. There are actually 7 or 8 wires inside the insulator. We don’t want to cut any of those wires. You will need to determine the wire gauge that is appropriate for these wires. Next, insert each wire into the large holes through the top down to the bottom. Then insert the wires from the bottom through the small holes next to the large holes.

15. Plug the battery into the battery clips. Insert the battery clips into PCB in the correct orientation. Notice the positive and negative battery terminals, match the terminals to

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the +/- symbols on the PCB. Use a rubber band to secure the battery to the PCB to stabilize the battery on the PCB prior to soldering.

16. Solder the battery clips into the BACK of the PCB. The front of the PCB has the writing on it. The back shows just the shiny pads. Remove the battery and wrap it two times with the blue painters tape and set aside.

17. Now, insert and solder the antenna wires as directed.

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