Power Generation Notes: Difference between revisions
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(New page: These are notes compiled from the peripherals mailing list <b>Power options</b> * Bicycle ** Dynamo (output typically 12V, 6W) *** Put 3 in parallel, Ouput 12V ~18W, might not be enough ...) |
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*** Put 2 in series, Output 24V ~12W, high end of XO’s input |
*** Put 2 in series, Output 24V ~12W, high end of XO’s input |
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** Alternator |
** Alternator |
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*** Are expensive in Peru, costs $300 approx for Korean “Tico” |
*** Are expensive in Peru, costs $300 approx for Korean “Tico” (Javier Comment on OLPC Peripherals list) |
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*** Could be built from scratch- copper wire and magnets that are imported |
*** Could be built from scratch- copper wire and magnets that are imported |
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*** Low rpm alternators are likely needed for bicycle generator allowing power output as low as 60 rpm |
*** Low rpm alternators are likely needed for bicycle generator allowing power output as low as 60 rpm |
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**** For a custom made alternator, lower rpms can be achieved by increasing the wire in the alternator, but this will also decrease the overall power output |
**** For a custom made alternator, lower rpms can be achieved by increasing the wire in the alternator, but this will also decrease the overall power output |
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*** Alternators could possibly be bought cheaply in US and shipped to other countries where it's more expensive |
*** Alternators could possibly be bought cheaply in US and shipped to other countries where it's more expensive (Caryl Comment on OLPC Peripherals list) |
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* Wind |
* Wind |
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** Typically need a tower about 2.5 times higher than nearest building or tree ~30 ft typically |
** Typically need a tower about 2.5 times higher than nearest building or tree ~30 ft typically |
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*Battery |
*Battery |
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** Can use a rechargeable battery for charge storage |
** Can use a rechargeable battery for charge storage |
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** Need a full wave bridge rectifier- |
** Need a full wave bridge rectifier- (Richard Smith Comment on OLPC Peripherals list) |
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** Chance of deep cycling LA car battery, typically don’t want to drain charge below 50% |
** Chance of deep cycling LA car battery, typically don’t want to drain charge below 50% |
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** Need a charging protection circuit, don’t output more than 14.5 V- |
** Need a charging protection circuit, don’t output more than 14.5 V- (Nick Foster Comment on OLPC Peripherals list) |
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Could charge a battery and then discharge to the XO- no need for a ultra-capacitor or flywheel, but there are additional power losses |
Could charge a battery and then discharge to the XO- no need for a ultra-capacitor or flywheel, but there are additional power losses |
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** Car battery- 12V output, circuitry to cut off, 35A for $100 |
** Car battery- 12V output, circuitry to cut off, 35A for $100 |
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** Need to charge XO at 1.5A and 12V for 2 hrs |
** Need to charge XO at 1.5A and 12V for 2 hrs |
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<b>Estimated Costs for Implementation |
<b>Estimated Costs for Implementation (Josh Seal Comment on OLPC Peripherals list)</b> |
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* Personal Solar: $20 per XO (Variable effectiveness and difficult for a |
* Personal Solar: $20 per XO (Variable effectiveness and difficult for a |
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Latest revision as of 20:27, 6 August 2008
These are notes compiled from the peripherals mailing list
Power options
- Bicycle
- Dynamo (output typically 12V, 6W)
- Put 3 in parallel, Ouput 12V ~18W, might not be enough voltage to charge XO
- Put 2 in series, Output 24V ~12W, high end of XO’s input
- Alternator
- Are expensive in Peru, costs $300 approx for Korean “Tico” (Javier Comment on OLPC Peripherals list)
- Could be built from scratch- copper wire and magnets that are imported
- Low rpm alternators are likely needed for bicycle generator allowing power output as low as 60 rpm
- For a custom made alternator, lower rpms can be achieved by increasing the wire in the alternator, but this will also decrease the overall power output
- Alternators could possibly be bought cheaply in US and shipped to other countries where it's more expensive (Caryl Comment on OLPC Peripherals list)
- Dynamo (output typically 12V, 6W)
- Wind
- Typically need a tower about 2.5 times higher than nearest building or tree ~30 ft typically
- Vertical axis wind turbines- Savonius, Darius wind turbines
Storage
- Battery
- Can use a rechargeable battery for charge storage
- Need a full wave bridge rectifier- (Richard Smith Comment on OLPC Peripherals list)
- Chance of deep cycling LA car battery, typically don’t want to drain charge below 50%
- Need a charging protection circuit, don’t output more than 14.5 V- (Nick Foster Comment on OLPC Peripherals list)
Could charge a battery and then discharge to the XO- no need for a ultra-capacitor or flywheel, but there are additional power losses
- Car battery- 12V output, circuitry to cut off, 35A for $100
- Need to charge XO at 1.5A and 12V for 2 hrs
Estimated Costs for Implementation (Josh Seal Comment on OLPC Peripherals list)
- Personal Solar: $20 per XO (Variable effectiveness and difficult for a
classroom environment)
- Classroom Solar: $35 per XO (Assuming peak efficiency - Roof solar with charge controllers and power distribution)
- Classroom Wind: $15 per XO (Assuming peak efficiency - Wind Turbine
tower outside school - variable output - Wind power generates the cube of velocity)
- Hand Crank: $15 per XO
- Cow Power: $13.75 per XO (35A Alternator ($300) + Gearing ($150) +
Batt ($100) = $550 for 40 XO)