Timeline for What determines the current flow in a load?
Current License: CC BY-SA 4.0
6 events
| when toggle format | what | by | license | comment | |
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| Mar 20, 2022 at 13:48 | vote | accept | Alex | ||
| Mar 20, 2022 at 10:12 | comment | added | Neil_UK | Not sure what an 'electric rod' is. A normal electric heater's resistance is nominally constant, so no, it doesn't change in response to the supplied voltage. You seem to have some strange idea that a constant power load is a thing. It can be approximated with a control system, but it doesn't exist passively the way more or less constant resistance resistor exists, or a constant temperature PTC ceramic heater exists. In a simulator, or exam question, then anything is possible. Just write the equation, and it exists. Real life is rarely as simple or obliging as simulators or exam questions. | |
| Mar 20, 2022 at 8:42 | comment | added | Alex | 11 "A constant power load varies it's impedance on change of input voltage to keep the power constant." Do an electric rod or a normal electric heater change their impedence according to the supplied voltage? | |
| Mar 19, 2022 at 11:51 | comment | added | Neil_UK | @Alex Yes, the electric heater is an interesting one. If you buy a PTC ceramic heater, that works like a constant temperature load, suddenly increasing its resistance as it gets to working temperature. You can then adjust the power it draws by varying the airflow. Metal element heaters, usually made with resistance alloy wires like nichrome, are more or less zero tempco, so their power goes very closely as the square of the applied voltage. | |
| Mar 19, 2022 at 11:04 | comment | added | Alex | What about an electric heater, electric or or any commonly used inductive load? Can they be regarded as constant power loads? | |
| Mar 19, 2022 at 9:49 | history | answered | Neil_UK | CC BY-SA 4.0 |