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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]
@@ Line 1: / Line 1: @@
 ====== Devices with power adapters ======
-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"))
-{{ 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.
-  * 12vdc, 2A (24w)
-  * 5vdc, 1A (5w, typical with usb)
+**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.
-===== common device voltages =====
+===== device voltages provided by adapters =====
@@ Line 25: / Line 27: @@
 ==== 5vdc ====
+{{ 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 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.
+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.
+Fancier ones ([[https://amzn.to/3aY4r9N|example]]) might have LED readouts and allow you to configure the output with buttons.
+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]]).
+==== boost converters ====
+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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