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| | | Propulsive power and overall efficiency | | |
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| | | Overall efficiencies of various motor manufacturers | | |
| | | Meaningful performance indicators Torqeedo provides meaningful performance indicators for boat drives. Basically, the power of a drive is measured according to how much propulsion it actually delivers for moving the boat. This power is referred to as the output or propulsive power. It is calculated by the thrust times the speed and can be expressed in watts or horsepower. Although the propulsive power forms an extremely informative index for boat drives, most manufacturers don't provide it. Suppliers of electric motors generally use the input power of their motors as the power rating. However, only a fraction of this value is actually available to the boat drive as propulsive power. The rest is lost - for example in the motor or propeller - as inefficiency. Manufacturers of combustion engines, on the other hand, usually give the power at the motor shaft as their index. Also here, only a fraction of this value is available as propulsive power: | | |
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| | | 50 45 40 35 30 25 20 15 10 5 0 | | |
| | | Torqeedo Travel 401 | | |
| | | Torqeedo Travel 801 | | |
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| | | *f Torqeedo ' r Cruise 2.0 | | |
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| | | Competitor: 2,200 W, 36 V | | |
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| | | Competitor: Competitor: 500 W, 12 V 1,000 W, 24 V | | |
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| | | 0 | | 500 1000 1500 2000 2500 Input power in watts | | |
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| | | Current times voltage Taken from the battery INPUT POWER | | Current times voltage Taken from cable | | Temporal division Torque at the motor Torque at the | | Power (thrust) at the boat times the speed of the boat | | |
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| | | of current times voltage | | shaft times the angular velocity of the motor shaft | | propeller shaft | | |
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| | | SHAFT POWER | | PROPULSIVE POWER | | |
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| | | Power specs of I Torqeedo ITogether with the input power results in the overall effi-I ciency (propulsive I power divided by I the input power) | | |
| | | Traditional power specs of combustion engines (high efficiency losses at the propeller not considered) | | |
| | | Traditional power specs of electric motors (all system losses not considered) | | |
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| | | 6 Catalogue 2007 | | |
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