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

Heater circuit parts

Perfboard (AKA solderable breadboard)

5 Watt ceramic resistors

Rocker switch

9-volt battery snaps

Wire: two ~ 6 in and two ~ 12 in

Shrink-wrap (AKA heat-shrink tubing)

Wire mesh (AKA hardware cloth)

Strip the ends of all 4 segments of wire

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

Twist the exposed metal wires together

Solder the twisted wires together to make the electrical connection permanent

Cover the connection with shrink-wrap

Use heat gun to shrink the wrap

Repeat with black wires – finished product

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

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

Cover solder joints with shrink-wrap

Completed rocker switch with wires

Place 3 resistors onto perfboard

Bend leads so that 3 resistors are in series

Solder leads together then clip excess

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

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

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

Cut and bend wire mesh into a cage

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