CEB Press/Manufacturing Instructions/Sensor Unit
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[edit] Manufacturing Instructions
Update: Do not use silicone as shown in the above video. 1-part silicone cures by atmospheric humidity penetration and will not cure in a deep sealed section like this. Also it releases acetic acid during cure which can corrode electrical parts. Use potting compound as shown in video below.
[edit] Discussion of Sensor Function
[edit] Tools
- Compatible Set of Soldering Iron, Solder, Soldering Stand, and Wet Sponge or Wet Paper Towel
- Straight Pattern Tin Snips
- Wire Strippers Compatible With 22 Gauge Wire
- Heat Gun
- Pliers
- Helping Hand
- Measuring Tape
- Wire Strippers Compatible With 8 Gauge Wire
[edit] Materials
- Hall Effect Sensor
- 1.5m of 4 Wire Underground Telephone Cable
- 2 part potting compound MAX MCR or equivalent
- [3] 3cm lengths of Shrink Tubing
- PVC Pipe with 2.5cm Outer Diameter, 1.5cm Inner Diameter, 9cm Length
[edit] Steps
- Using the tin snips, cut the sleeve of the telephone wire by 5cm and 20cm at both ends. The cutting tolerance is 2cm.
- Using the tin snips, cut the orange-white wire at both ends of the telephone wire.
- Using the wire strippers, strip the bluewhite, blue, and orange wires of the telephone wire by 2cm at the 5cm end and by 1cm at the 20cm end. The stripping tolerance is 0.5cm.
- Insert 3cm shrinktubing into the 5cm blue, blue-white, and orange wires.
- Bend the sensor prongs and the exposed metal of the 5cm wires into hooks such that the 3 prong hooks can latch onto the 3 wire hooks to facilitate soldering. Use pliers to pinch the hook connections during the soldering process.
- Using the soldering set and the helping hand, solder the hall-effect sensor prongs to the 5cm wires. The orientation of the soldering connections is such that, when you can see the sensor text and its prongs pointing downward, from left to right the colour of the wires to be soldered are: bluewhite (for 5V+), blue (for GND), and orange (for Signal).
- Using the heat gun, cover the soldered prong-to-wire connections with the shrinktubing then apply heat to the now-covered connections. The shrinktubing should shrink, forming a tight insulating seal for each of the prong-to-wire connections.
- Insert the wired hall-effect sensor into the PVC tube leaving 2cm of space at the non-insertion end of the tube.
- Seal the wire to the tube with PVC electrical tape, which will retain the liquid potting compound while it cures.
- Mix the potting compound and pour it into the tube such that the tube is completely filled in.
- Gently set the sensor unit with the wire end down and wait 24 hours for the potting compound to cure.
