Hi there -
I'm hacking together a few things for my new (old) car: I want to plug in to the cigarette lighter jack, drop the voltage to 5V, and have two jacks in parallel coming from that to charge my cell phone (5V, 1A is the rating on the wall-wart charger, conveniently) and/or my USB devices (also 5V of course, using the standard USB charger hack at: http://forum.hackedgadgets.com/viewtopic.php?p=3152 ).
- First question is about the voltage drop: my understanding is that you can use a DC-DC voltage converter or use a voltage-dropping resistor (after testing the car's actual voltage.)
The resistor is simpler, it would seem, but I'm curious as to the pros/cons of using a voltage converter? It'd be nice (maybe just psychologically) to not be wasting the burned off energy all the time.
- Also, the variance from 12V that cars actually have: is that per battery or per car or both?
- Any issue about the nature of the power coming from the car? Not sure what would happen; noisy or unpredictable or spikes or dropouts in voltage/current, undervoltages, or whatever else might hurt the devices?
Any info greatly appreciated.
Thanks!
-Casey
I'm hacking together a few things for my new (old) car: I want to plug in to the cigarette lighter jack, drop the voltage to 5V, and have two jacks in parallel coming from that to charge my cell phone (5V, 1A is the rating on the wall-wart charger, conveniently) and/or my USB devices (also 5V of course, using the standard USB charger hack at: http://forum.hackedgadgets.com/viewtopic.php?p=3152 ).
- First question is about the voltage drop: my understanding is that you can use a DC-DC voltage converter or use a voltage-dropping resistor (after testing the car's actual voltage.)
The resistor is simpler, it would seem, but I'm curious as to the pros/cons of using a voltage converter? It'd be nice (maybe just psychologically) to not be wasting the burned off energy all the time.
- Also, the variance from 12V that cars actually have: is that per battery or per car or both?
- Any issue about the nature of the power coming from the car? Not sure what would happen; noisy or unpredictable or spikes or dropouts in voltage/current, undervoltages, or whatever else might hurt the devices?
Any info greatly appreciated.
Thanks!
-Casey