I use something like
this, only mine doesn't have the emergency light or air compressor. I got it a couple of years ago at Radio Shack. It was on clearance, and I paid something like $26 for it. And to be perfectly honest, I did actually buy it to launch rockets, and not to jump start my car.
I just clip the two cables to the two corresponding battery connectors on my Interlock Controller, and launch away. I have never even gotten the battery as much as half-drained. It is a sealed lead-acid battery, so it loves to be charged. Mine weighs about 8 lbs.
As long as we are talking about the AT Interlock Controller, let me suggest a slight modification to make it much more versatile. The mod is simple:
At Radio Shack, pick up:
- a small spool (or partial spool) of 18-gauge speaker wire (two conductor)
- a pack or two of bullet connectors, in the size appropriate for 18-gauge wire (the kind with the red covers)
- a pack or two of micro-clips
- a pack of heat-shrink tubing or a can of liquid insulating tape
You will also need wire cutters, a wire crimping tool, a soldering iron and some lead-free silver solder.
I used the red and black stranded 18-gauge speaker wire from RS.
When you get home, take out your Interlock Controller and your pair of wire cutters and clip off that not-very-adaptable Interlock Clip, about 8" or so back from the clip. Now take the cut ends of the leads coming from the controller and the leads coming from the Interlock Clip, and separate them for about 2" back from the ends. Remove some insulation from each lead and install a pair of bullet connectors (one of each, a male connector and a female connector) on the two leads coming from the controller, and install another pair on the Interlock Clip leads. Use the crimp tool to crimp the connectors onto their respective leads, and then slip a short length of heat-shrink tubing over the red sleeve of each connector, overlapping some of the wire lead right behind it, and heat them with a heat gun or hair drier until they shrink down and form tight seals around the joint where the wire lead enters the connector sleeve. (If you bought liquid insulating tape instead, brush some onto this same area.)
Now you are no longer limited to using just the Interlock Clip with your controller. Go ahead and make a pair of micro clip leads by cutting a length of the 18-gauge speaker wire, soldering on a pair of microclips onto one end and a pair of bullet connectors (remember, one male and one female) to the other end. When you want to use micro clips (which will be most of the time), just plug the attachment into the connectors on the controller's leads, and disconnect them on plug in the Interlock attachment when you are launching with Copperhead igniters. If you terminate each pair of conductors (strands or wires) in all of your leads with one male bullet connector and one female connector, you will be assurred of always being able to connect everything to your controller's leads.
I also used the
plans shown at
Rocketry Online's InfoCentral to make various clip whip configurations, and I terminated the trunk leads with bullet connectors, so that I can just plug the whips into the Interlock Controller's leads and have solid connections all the way to the clips.
MarkII
