convert baby swing from batteries to plug-in

I have a newborn and got sick of constantly buying batteries for the various swings and vibrating chairs we have. So I decided to convert them all from battery power to wall plug-in. I ordered these parts from radioshack:

• plug connector
• panel-mount socket connector
• 6V AC to DC power adapter (edit: product discontinued. It was 1.8 A, but don't know actual current draw needed)
• wire

All our swings took 4 batteries, each battery is 1.5V, so I got 6V power adapters. I would recommend NOT going to a radioshack store - the cheapest power adapter I found in the store was $20, while it's $1.50 online.


You'll also need the following tools:

• screwdriver
• drill with large bit (the largest bit I had was 3/8", but 1/2" probably would have been better)
• voltmeter
• soldering iron and solder
• wire cutters
• wire strippers
• electrical tape

After getting the parts together, here is what you do:

1. Unscrew and remove the battery compartment door and drill a hole in it. You want the hole just a bit larger than the socket. Be persistent - drill bits are not the best tool for drilling hard plastic. Be careful not to let the bit bind up and turn the door into a spinning wrist slasher.
2. Screw the panel mount socket connector into the new hole in the door.
3. Solder two wires (~6") to the socket
4. Solder the ground/negative wire (outer socket connection) to one of the end springs. Usually you can see which terminals are shorted. In the picture below, the spring on the bottom-right is shorted to the terminal next door, so it's the wrong one.
5. Solder the positive wire (center socket connection) to the flat connection on the other side. This is harder to solder because it's a large flat piece of metal - use a lot of heat and solder.
6. Use the wire cutters to cut of the power adapter connector and VERY carefully plug it into the wall and use your voltmeter to figure out which wire is positive and which is negative/ground.
7. Carefully unplug the power adapter and solder the wires onto the plug connector. This is probably the hardest step because the connector is quite small - be patient. Once you are done, use electrical tape to keep the two wires from shorting inside the connector.
8. Plug it in and see whether you did everything correctly!