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electrical:12v:wallwart [2021/05/02 18:19] frater_secessus |
electrical:12v:wallwart [2021/05/02 18:48] (current) frater_secessus [common device voltages] |
====== Devices with power adapters ====== | ====== Devices with power adapters ====== |
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It is a common misconception that inverters are needed for everything that [[electrical:shore_power|plugs into a wall]]. Inverters are generally required only for devices that run off wall power with cord that runs permanently into the device. Example: table lamp. | {{ https://ae01.alicdn.com/kf/HTB1ZNnNLXXXXXbyXpXXq6xXFXXXd/12V-2A-EU-Plug-AC-Adapter-DC-Power-Supply-Plug-EURO-Regulation-Wall-Wart-Charger-5.jpg?125}} |
| It is a common misconception that inverters are needed to run devices with wall adapters. That is usually not the case. Devices that have a plug that has a block at the end (or elsewhere) are typically using **DC power**, which is what is already in your car. No inverter needed. The adapter is there only to change 120vac to the required amount of DC voltage.((ie, "rectification")) |
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{{ https://ae01.alicdn.com/kf/HTB1ZNnNLXXXXXbyXpXXq6xXFXXXd/12V-2A-EU-Plug-AC-Adapter-DC-Power-Supply-Plug-EURO-Regulation-Wall-Wart-Charger-5.jpg?125}}Devices that have a "wall-wart" power adapter that can disconnect from the device are typically using **DC power**, which is what is already in your car. If you inspect the device or adapter it will usually indicate something like: | Inverters are generally required only for devices that run off [[electrical:shore_power|wall power]] with cord that runs permanently into the device. Example: table lamp. |
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* 12vdc, 2A (24w) | |
* 5vdc, 1A (5w, typical with usb) | |
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| **How to decide**: //If you need an inverter for other reasons// it is often reasonable to run DC adapters from that inverter.((Exception: really big inverters with high [[electrical:12v:loads|parasitic loads]] running small adaptes)) It is rarely reasonable to buy an inverter solely to run DC adapters. |
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===== common device voltages ===== | |
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| ===== device voltages provided by adapters ===== |
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==== 5vdc ==== | ==== 5vdc ==== |
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| {{ https://images-na.ssl-images-amazon.com/images/I/41tHeiafxSL._SY90_.jpg?125}}5vdc is most often seen in USB. If your device needs 5v((up to ~2A)) you can likely run it from a USB to plug adapter. [[https://amzn.to/2RlNbEp|Example]]. You will have to assess the plug size. |
==== other voltages ==== | ==== other voltages ==== |
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| Other voltages like 9v and 6v are less common. If you have multiple devices that use the same odd voltage you might want to buy a DC-DC "buck" converter and adjust it for the desired voltage. |
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| Inexpensive ones ([[https://amzn.to/2QFmHOx|example]]) typically have a "pot" (screw to turn on a potentiometer) to adjust voltage, so bring your multimeter. They are so inexpensive you might keep a few pre-tuned and labeled for specific voltages. |
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| Fancier ones ([[https://amzn.to/3aY4r9N|example]]) might have LED readouts and allow you to configure the output with buttons. |
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| If you have an adapter with a weird output voltage and don't want to mess with buck converters a very small, inexpensive inverter might be the thing. Even one small enough to run from the cigarette lighter ([[https://amzn.to/3gWOKni|example]]). |
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| ==== boost converters ==== |
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| It's rarer still for devices to use adapters that make more than 12vdc. Increasing voltage from 12vdc to a higher DC voltage requires a "boost" converter ([[https://amzn.to/33bM39j|example]]). The laptop adapters mentioned earlier are boost converters. |
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