Difference between revisions of "OPTOFAST-2"
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Blwikiadmin (talk | contribs) (Created page with "== Features == * Opto-Isolator card * 4-Channels * 4N25 Optoisolators * Input /Output isolation * Transistor driver for Opto LED reduces required drive from 10 mA to under 50...") |
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* 49x49mm | * 49x49mm | ||
* (4) 4-40 mounting holes | * (4) 4-40 mounting holes | ||
| + | |||
| + | == Schematic (One channel) == | ||
| + | |||
| + | [[File:OPTOFAST-2-Schematic-TransIn.PNG]] | ||
| + | |||
| + | * U1 represents U1-U4 (channels 1-4) | ||
| + | * Q1 represents Q1-Q4 (channels 1-4) | ||
| + | * R1 (VCC) represents R1,R4,R7,R10 (channels 1-4) | ||
| + | * R2 (DIR) represents R2,R5,R8,R11 (channels 1-4) | ||
| + | * R3 (BASE) represents R3,R6,R8,R12 (channels 1-4) | ||
| + | * R13 (FAST) represents R13-R16 (channels 1-4) | ||
| + | * R17 (COLL) represents R17-R20 (channels 1-4) | ||
| + | |||
| + | === Input Options === | ||
| + | |||
| + | * Refer to schematic for impact of options | ||
| + | |||
| + | ==== Use Input Transistor - Standard Option ==== | ||
| + | |||
| + | * Common VCC in option | ||
| + | * Install transistor Q1 | ||
| + | * R1 = 150 | ||
| + | ** LED current is 3.5V/150 Ohms = 23 mA | ||
| + | ** CTR = .20, 4.7 mA | ||
| + | * R2 = Do not populate | ||
| + | * R3 = 10K | ||
| + | ** Base drive ~ (Vin - 0.7V)/R3 | ||
| + | ** At 5V drive this is 4.3V/R3 | ||
| + | *** Using R3=10K at 5V this is 0.43mA Ib | ||
| + | *** HFE (MMBT3904) = 100 min | ||
| + | *** That is potentially 43 mA (in the switching range of the transistor) | ||
| + | **** Collector resistor and LED voltage drop are current limiter | ||
| + | ** At 3.3V drive this is (3.3-0.7)/10K = .26mA Ib | ||
| + | *** HFE = 100 min | ||
| + | *** That is 26 mA (in the switching range of the transistor) | ||
| + | * H1 do not short | ||
Revision as of 23:56, 9 January 2020
Contents
Features
- Opto-Isolator card
- 4-Channels
- 4N25 Optoisolators
- Input /Output isolation
- Transistor driver for Opto LED reduces required drive from 10 mA to under 500 uA
- Input channels share their own common VCC/Ground
- Output channels share their own common Vcc/Ground
- 8-pin header for input
- 8-pin header for output
- Configuration Options
- Speed enhanced
- Bypass Input transistors
- Remove Output collector resistors
- 49x49mm
- (4) 4-40 mounting holes
Schematic (One channel)
- U1 represents U1-U4 (channels 1-4)
- Q1 represents Q1-Q4 (channels 1-4)
- R1 (VCC) represents R1,R4,R7,R10 (channels 1-4)
- R2 (DIR) represents R2,R5,R8,R11 (channels 1-4)
- R3 (BASE) represents R3,R6,R8,R12 (channels 1-4)
- R13 (FAST) represents R13-R16 (channels 1-4)
- R17 (COLL) represents R17-R20 (channels 1-4)
Input Options
- Refer to schematic for impact of options
Use Input Transistor - Standard Option
- Common VCC in option
- Install transistor Q1
- R1 = 150
- LED current is 3.5V/150 Ohms = 23 mA
- CTR = .20, 4.7 mA
- R2 = Do not populate
- R3 = 10K
- Base drive ~ (Vin - 0.7V)/R3
- At 5V drive this is 4.3V/R3
- Using R3=10K at 5V this is 0.43mA Ib
- HFE (MMBT3904) = 100 min
- That is potentially 43 mA (in the switching range of the transistor)
- Collector resistor and LED voltage drop are current limiter
- At 3.3V drive this is (3.3-0.7)/10K = .26mA Ib
- HFE = 100 min
- That is 26 mA (in the switching range of the transistor)
- H1 do not short
