User:Chotee/NoFeedback-ManagementIntervention

1mx1m screen of RGB lights that slowly and independently change colour. All patterns are just your mind playing tricks on you.

Alternative name:

• Free-Runner / Management-Intervention

Parts

• [Ordered] LEDs - https://nl.aliexpress.com/item/free-shipping-500pcs-5mm-Straw-Hat-Colorful-Slow-Flashing-Flash-RGB-Red-Blue-Green-LED-Leds/32231092414.html
• 11 x duct (11*€3.19) https://www.gamma.nl/assortiment/kabelgoot-kunststof-wit-20x10-mm/p/B651828
• 10 Bouten M5x80mm €8 - https://www.gamma.nl/assortiment/gamma-slotbout-m6x80-mm-verzinkt-20-stuks/p/B458213
• 1000x1000mm Plexiglas - €23 - https://www.gamma.nl/assortiment/martens-acrylplaat-transparant-100x100-cm/p/B151681
• 2 x 1m 5mm staal/hout

Electronics

• 500 Slow color changing RGB leds.
  • max led forward current is 20mA.
  • RGBs forward-voltage oscillates between 3.2v and 3.8v (±15%)
  • LEDs max continuous current at 20mA.
• 22x22 leds (484) [sqrt(500) = 22.36..]

20v supply

• 20v/3.8 (V-max-led-forward) = 5.2 LEDs; 5 LEDs in a chain.
• There are 96.8 chains [484/5]
• Vmax = 5 * 3.8Vf = 19v; 1v left.
• Vmin = 5 * 3.2Vf = 16v; 4v left.
• current limit power-max: 4v*20mA = 80mW.
• Total Current: 20mA * 97 = 1.94A
• Total power: 1.94A * 20v = 38.8w
• 22 leds; 4x5led chain + 1x2led chain.
  • 2 led chain needs a 470ohm ¼Watt resistor (or 2x1000ohm in paralel) to drop the voltage.

Components

• R1 = 100k
• R2 = 1k8
• Rs = 10
• Opamp >20v;
  • *Single* channel opamp: LM321 -- €1.99 (100pcs) -- https://nl.aliexpress.com/item/Free-Shipping-100PCS-100-NEW-LM321MFX-LM321MF-LM321-A63A-SOT23-5/1924012475.html -- http://www.ti.com/lit/ds/symlink/lm321.pdf
• Mosfet. >20v; >20mA:
  • From the OPL: BSS138W-7-F; 50V; 200mA -- €1.36 (100pcs) -- https://nl.aliexpress.com/item/50PCS-BSS138LT1G-SOT23-BSS138-SOT-MOSFET-SMD-new-and-original-IC-free-shippin/32518915182.html -- http://www.onsemi.com/pub/Collateral/BSS138LT1-D.PDF
• a 100nF capacitor as small voltage buffer.

Circuit

[from http://www.falstad.com/circuit/circuitjs.html]

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g 416 592 416 624 0
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162 752 272 752 320 1 3.2 1 0 0 0.01
162 752 320 752 368 1 3.2 1 0 0 0.01
162 752 368 752 416 1 3.2 1 0 0 0.01
r 752 528 752 592 0 10
w 544 592 608 592 0
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a 608 464 688 464 1 12 0 1000000 0.11134962704993533 0.11137629276054098
r 544 352 544 448 0 100000
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r 544 448 544 560 0 560
162 752 224 752 272 1 3.2 1 0 0 0.01
162 752 176 752 224 1 3.2 1 0 0 0.01
w 752 416 752 448 0
w 752 416 688 416 0
c 688 416 688 176 0 1.0000000000000001e-7 -14.836678863009816
w 544 176 688 176 0
w 688 176 752 176 0
o 26 64 0 4099 20 0.00009765625 0 2 26 3
o 6 64 0 4099 20 0.05 1 2 6 3
o 10 64 0 4099 0.625 0.05 2 2 10 3