Go 12V » Historie » Version 19
Maximilian Seesslen, 04.12.2025 17:26
| 1 | 1 | Maximilian Seesslen | h1. Go 12V |
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| 3 | The 5V line already dropped to 4,7V in good condition. I had big problems with |
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| 4 | * sensemux |
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| 5 | 7 | Maximilian Seesslen | * CANDis displays got reseted on bad conditions |
| 6 | * Radio modules got stuck |
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| 7 | 1 | Maximilian Seesslen | * Not sure if other issues have been related to poor voltage |
| 8 | * maybe need higher voltages in the future for bigger displays |
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| 9 | |||
| 10 | 24V would be nice but some CAN transceivers can only toleryte CAN-Hi/Low up to 14V. |
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| 11 | Hard to find voltage regulators from 12V to 3V. |
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| 12 | Is there one that can handle both 12V and 5V? -> CANDis |
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| 13 | 2 | Maximilian Seesslen | |
| 14 | 4 | Maximilian Seesslen | https://www.reichelt.de/de/de/shop/kategorie/lineare_spannungsregler-8693?filter=207%23~%23%2A%23~%23SOT-23-5%20%23~%23SOT-23-5%23~%230&PAGE=2 |
| 15 | 5 | Maximilian Seesslen | https://www.tme.eu/at/katalog/ldo-festspannungsregler_112880/?params=35:1443487,1996156;364:1443548,1443479 |
| 16 | 6 | Maximilian Seesslen | "Detailed filtered":https://www.tme.eu/at/katalog/ldo-festspannungsregler_112880/?params=35:1443487,1996156;364:1443548,1443479;365:1502611,1521533,1443472,1455153,1502656,1498624,1455142,1443466;624:1931429,1890792,1543611,1502480,1996008,1890800,1502370,1898224&productListOrderDir=ASC&productListOrderBy=1000014&onlyInStock=1 |
| 17 | 4 | Maximilian Seesslen | |
| 18 | 3 | Maximilian Seesslen | MCP 1754-3302CB: SOT-23-3; max. 17,4V; 300mV dropout; 150mA; 3,3V |
| 19 | MCP1703AT3002ECB: 3,3V |
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| 20 | 4 | Maximilian Seesslen | MCP1755: pin 4 needs to be high |
| 21 | 1 | Maximilian Seesslen | Display braucht schon 120mA: ->250mA |
| 22 | 7 | Maximilian Seesslen | SPX3819 alleskönner |
| 23 | 11 | Maximilian Seesslen | LDI559-3.3EN-DIO Liesst sich sogar noch besser; da gibts sogar eine 500mA Variante (LDI8119-3.3EN-DIO); Eingang 1,8...18V. Dann koennen bei CANDis die hohen Vorwiederstaende vor dem Buzzer wieder raus :D. CANBuz can auch gas geben. |
| 24 | 12 | Maximilian Seesslen | * 35V 10µF kondensatoren gibts gerade noch so: GRM188R6YA106MA73J |
| 25 | 14 | Maximilian Seesslen | * Hoehere Spannungsfestigkeit (50V) gibts erst wieder ab 2,2µF, da ist man bei 12V noch fast 100% |
| 26 | * Der 300mA variante reichen 1µF, dropout sind 0,8V |
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| 27 | 15 | Maximilian Seesslen | |
| 28 | h1. Problem |
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| 29 | |||
| 30 | (12-3)*0,120=1,08W; das kann der "gute" LDO schon gar nicht. |
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| 31 | Candisplay haette selber nur 0,36W. |
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| 32 | 16 | Maximilian Seesslen | |
| 33 | LMR51430 ist SOT23-6, die notwendigen Induktivitaeten fuer die kleinen Stroeme <1A gibts auch schon in 0603. |
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| 34 | 17 | Maximilian Seesslen | Bei kleinen Wirkungsgraden immer noch >90% Effizienz. |
| 35 | D.h. es werden z.B. 0,0133333334A mehr benoetigt, 0,04W |
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| 36 | 18 | Maximilian Seesslen | |
| 37 | 016211405, schwarzes Kabel. |
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| 38 | |||
| 39 | h1. Rechnerisch |
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| 40 | |||
| 41 | 19 | Maximilian Seesslen | 0,34mm2; AWG #26 |
| 42 | 18 | Maximilian Seesslen | "Daten":https://www.tme.eu/Document/2b58be559be4a603b8eec8e10ffb0c00/LIYY-EN.pdf |
| 43 | 57.0 Ohm pro Kilometer; 5,7 Ohm pro 100m; 11,4 Ohm both directions |
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| 44 | |||
| 45 | max. 5V, 0,5A= 10 Ohm |
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| 46 | CANDis 3V/0,120= 25 Ohm |
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| 47 | Wohnung SQRT(77) × 4 = 35,08 |
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| 48 | (57 / 1000) × 70 × 2 = 399/50 = 7 + 49/50 = 7,98 Ohm |
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| 49 | 19 | Maximilian Seesslen | |
| 50 | U2=((U*R2)/(R1+R2) |
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| 51 | = (5*25)/(25+7,98) = 3,8V |
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| 52 | |||
| 53 | ZHR max. 0.13mm²? AWG #26 |
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| 54 | |||
| 55 | AWG 26 -> 0,14 mm² |
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| 56 | AWG 22 -> 0,34 mm² |