For this project I deconstructed an old children’s sewing machine. This machine had two basic functions, a light on the front and a motor that moved gears in a way that allowed the needle on the machine to go up and down to sew. The components of the sewing machine which I was able to identify were:
- A 6V power source
- 3 diodes
- 1 resistor
- A basic spinning motor
- A switch (within the foot pedal)
- A small light
- A battery pack (optional to use instead of the wall input)
The components were soldered to wires and to each other.
The current in the sewing machine moves in the following pattern:
In order to deconstruct the sewing machine I started by removing all of the screw on the back of it’s shell. Next I removed the back half of the shell and pulled out the components including the light, motor, and battery pack.
Something I learned in deconstructing this machine is that the two diodes which precede the battery pack likely have to purposed. The first purpose being to convert the wall input power from AC to DC for the motor, this is why they come before the battery pack (the power from the battery pack is already DC). The second purpose of the diodes is to prevent power from coming back through the current in the wrong direction. This could happen because there is a hand turned crank on the side of the machine that allows the user to move the needle up and down at their own slow speed. Using this hand crank would cause the motor to move and could create energy which would then try to move through the wires back to the power input. The diodes prevent any created energy from moving back through in the wrong direction.