Gateway to SpaceHomework #04

Name:______Time Spent on Homework:______

Assigned on 09-13-07

Due on09-18-07(Please bring hardware completed during this homework to class)

This is a team assignment and must be completed with the team. Each team must complete and then test two timing circuits. Please follow the steps below completely and in order. Each step should be initialed by the person who completed the step. Each team will need a 12 Volt supply, a voltmeter and 2 soldering iron kits to complete this assignment. You will need to return these to Chris with you completed hardware on the due date for this assignment.

You will need to download the Supplement HW_#4 Handout for this assignment. DO NOT FOLLOW THE INSTRUCTIONS THAT COME WITH THE KIT.

Step / Initials
Step 1a: Layout timing circuit kits and set parts out
Step 1b: Study the PC Board front and back
Step 2: Put connectors together
Step 3: Solder connecter to board
Step 4: Solder relay to board
Step 5: Solder resistors to board
Step 6: Solder diodes (watch polarity)
Step 7: Install trimpots or variable resistors. Do not adjust at this time.
Step 8: Install red LED
Step 9: Install Capacitor C1
Step 10: Install Capacitor C2 and C3. Watch polarity. Positive lead is the long lead and goes in the positive hole
Step 11: Solder socket. Be careful of solder bridges.
Step 12: Install 555 Timer chip. Be careful of orientation.
Step 13: Install A23 batteries (12 V) into specially made case
Step 14: Use voltmeter to verify you have 12 V
Step 15: Hook Up 12 V battery as shown below:
Step 16: Flip switch ON (should here a loud click and see the red LED light up). If it doesn’t, turn off switch immediately. Look at solder connections and make any corrections.
Step 17: Adjust Pause and Pulse to get timing interval to around 3 minutes. (This will be explained in class but do it as part of this assignment)
Step 18: Disconnect 12 V battery and package everything to bring to class on Tuesday.

ASEN/ASTR 2500- 1 -