1. Building a Heater Circuit for a Near-Space Payload
AEM 1905: Spaceflight with Ballooning
University of Minnesota

2. Heater circuit parts

3. Perfboard (AKA solderable breadboard)

4. 5 Watt ceramic resistors

5. Rocker switch

6. 9-volt battery snaps

7. Wire: two ~ 6 in and two ~ 12 in

8. Shrink-wrap (AKA heat-shrink tubing)

9. Wire mesh (AKA hardware cloth)

10. Strip the ends of all 4 segments of wire

11. Line up one short wire end with the
3 red ends from the 3 battery snaps

12. Twist the exposed metal wires together

13. Solder the twisted wires together to make
the electrical connection permanent

14. Cover the connection with shrink-wrap

15. Use heat gun to shrink the wrap

16. Repeat with black wires – finished product

17. Wrap one end of each long wire to the
2 tabs on the back of the rocker switch

18. Solder wires in place – may require turning
up the soldering iron temperature a bit

19. Cover solder joints with shrink-wrap

20. Completed rocker switch with wires

21. Place 3 resistors onto perfboard

22. Bend leads so that 3 resistors are in series

23. Solder leads together then clip excess

24. Connect switch, batteries, and resistors
in series; put on the shrink-wrap first.

25. Bend wires when making connections so
any strain is carried by wire, not by solder.

26. Slide down and shrink the wrap – here
is the completed heater circuitry

27. Cut and bend wire mesh into a cage

28. Cover resistors with wire cage to prevent
accidental contact with heating elements