Kerjasama
SENI
KECANTIKAN & KESEJAHTERAAN
KRAFTANGAN
BUDAYA & SEJARAH
HIBURAN
ALAM SEKITAR
MAKANAN & MINUMAN
KEJURUTERAAN TERBALIK
SAINS
SUKAN
TEKNOLOGI
BOLEH PAKAI
Bathroom Scale: Four Flat Load Cells Between Two Plates (Angel, 1991)
A floor scale only as thick as two plates. Four flat load cells sit in the corners between a base and a top plate; their strain gauges are wired into one bridge, so the signal is the sum of the four loads wherever you stand.
Result: a low digital bathroom scale reading in pounds or kilograms. The patent gives under 0.05 % non-linearity, hysteresis and non-repeatability, and under 0.1 % error from off-centre loads; its feet let it stand on thick carpet.
Source: S. Angel, US Patent 4,993,506 (1991). Unknown: the plate material and size, the maximum load, and the circuit. Ours: ebonite for the hard rubber, epoxy, the amplifier and display parts. Picture: patent drawing (Fig. 5).
Lanjutan
2 days
Arahan
1
1
Mount the four load cells
Mount the four load cells
Put one load cell in each corner of the rigid base plate. Screw each one down to small flat raised pads on the plate. Place the pads away from the edge of the cell's beam, so that fixing the cell does not change its sensitivity. Under each cell, tap two holes through the base for the overload screws. Not given: the plate material and size.
Bahan untuk langkah ini:
Sel beban4 keping
Tapak dan plat atas penimbang1 base and top plate
Skru mesin8 cell screwsAlatan diperlukan:
Set pemotong ulir
Set pemutar skru
Dimensi tidak diketahui2
2
Wire one bridge and the readout
Wire one bridge and the readout
Each cell's two gauges are half a Wheatstone bridge. Join the four halves into one full bridge, one half at each corner, so the bridge gives a signal in step with the sum of the four loads. The signal is amplified, turned into numbers by an analog-to-digital converter, worked into pounds or kilograms and shown on a display. Put the electronics and batteries in the space between the plates. Not given: the circuit. Ours: an op-amp and a segment LCD.
Bahan untuk langkah ini:
IC penguat kendalian1 amplifier
Penukar Analog-ke-Digital1 keping
Panel LCD segmen1 keping
Bateri1 as the circuit needs
Wayar penyambung1 as needed
Dawai Pateri1 a littleAlatan diperlukan:
Alat pematerian3
3
Fit the top plate on hard rubber pads
Fit the top plate on hard rubber pads
Glue four flat round pads of a rigid but slightly yielding material, such as hard rubber, under the top plate. Give each pad small round studs that snap into the two load holes of its cell, so the weight goes in at the centres of those holes. The pads soften impacts when something is dropped on the scale and take up sideways forces as the top plate bends. The snaps let the top plate be pulled off for repairs. Ours: ebonite and epoxy.
Bahan untuk langkah ini:
Rod ebonit1 four pads
Epoksi dua komponen1 a littleAlatan diperlukan:
Gergaji Besi4
4
Fit the feet
Fit the feet
Under the base, below each cell, fix a shallow foot of flexible material such as hard rubber, rounded underneath. Put its lowest point exactly below the centre of the cell's beam: the floor then pushes up at the beam's centre without bending it, and the scale works on thick carpet or uneven floors. Ours: ebonite.
Bahan untuk langkah ini:
Rod ebonit1 four feetEpoksi dua komponen1 a littleAlatan diperlukan:
Gergaji Besi5
5
Set the overload stops
Set the overload stops
Load the scale to its maximum capacity. Turn the short screws in from below until they just touch the arms of each cell's loading element, then lock them with adhesive. Any heavier load now rests on the screws instead of bending the cells further. Not given: the maximum capacity. Ours: calibration weights and epoxy.
Bahan untuk langkah ini:
Skru mesin8 overload screwsEpoksi dua komponen1 a littleAlatan diperlukan:
Set pemberat penentukuranSet pemutar skruBahan
11- 4 kepingPemegang Tempat
- 1 base and top platePemegang Tempat
- 8 overload screwsPemegang Tempat
- 1 amplifierPemegang Tempat
- 1 kepingPemegang Tempat
- 1 kepingPemegang Tempat
- 1 as the circuit needsPemegang Tempat
- 1 as neededPemegang Tempat
- 1 a littlePemegang Tempat
- 1 four feetPemegang Tempat
- 3 a littlePemegang Tempat
Alatan Diperlukan
6- Pemegang Tempat
- Pemegang Tempat
- Pemegang Tempat
- 2 vendors sell this, none ship to you yetPemegang Tempat
- Pemegang Tempat
- Pemegang Tempat
Bahan Blueprint Bersambung
Blueprint ini membuat
Blueprint berkaitan
Blueprint ini berkongsi pengetahuan — teknik, bahan atau prinsip
CC0 Domain Awam
Blueprint ini dikeluarkan di bawah CC0. Anda bebas menyalin, mengubah, mengedar, dan menggunakan karya ini untuk sebarang tujuan, tanpa meminta kebenaran.
Sokong Pembuat dengan membeli produk melalui Blueprint mereka di mana mereka memperoleh Komisen Pembuat ditetapkan oleh Penjual, atau cipta iterasi baru Blueprint ini dan sertakan ia sebagai sambungan dalam Blueprint anda sendiri untuk berkongsi hasil.