ArcWindsor
New Member
I recently acquired two AC converter boxes that plug into the wall and output lower DC voltages. I have a few questions about each. I posted pictures of the specs (stickers) on the boxes at the bottom of this post.
The first one is a wall charger that converts 100-120VAC to 3-12VDC. It has a 1200mA output max and is meant for being a universal charger. I can select different voltages, but I'm typically going to use 12V. My point is to use it for several purposes...
1) testing some 12VDC car things (such as LEDs and relay coils) to make sure they work before wiring them into the car. This makes it so that I can test stuff right in the house in the winter instead of freezing outside to use the car battery
2) to power some LEDs (with some switches) for home lighting. This is just for lighting up some small areas for seeing or decoration... hobby
3) to charge peripheral devices whose wall chargers are lost/broken or didn't even come with a wall charger. For a lot of my devices, I have car chargers but no wall chargers. So using the converter box, I can avoid finding/buying wall chargers and going outside to the car just to charge it.
So I have a few questions about using this:
- First is the fusing safety. I'm assuming that since its 12VDC, I would select the wire gauge/fuse value in the same manner as if I was in the car installing something. So I plan to use 24AWG with a 500mA fuse (probably much smaller than necessary). I feel safe with this. What do you think?
- Secondly, the box has an output-voltage selector switch. I can select 3V, 4.5V, 6V, 7.5V, 9V, and 12V DC. So my question is that since I'm not used to voltages other than 12V, if I was to use 9V (or something less than 12V), then would the fusing be the same? For ex, assume the max fuse size for 24AWG is 3A on 12V, but what would be the max fuse size for 24AWG on 9V? Would it go up or down? I'm typically going to use the 12V setting only, but I'm asking this just in case I ever decide to use a lower one. Would I be safe using the 500mA fuse on 24AWG for all the voltages?
- Using this box on the 12VDC setting, is it okay to test 12VDC relay coils (the kind I plan to use in the car) to make sure the relay works properly? I always test my relays before installing them in the car. The box wasn't really designed to power relay coils, so that's why I'm asking. I don't know much about inductive spikes and whether or not they can mess with the box. Of course the coil's current will be under the max limit.
That's all for the 12V box.
The second box I have converts the wall outlet to an 18.5VDC output. I wanted to power some LEDs with this box too. I know its not okay to power LEDs rated at 12VDC (they have resistors for 12V car 'plug n play') using the 18.5V box, but what if I add extra resistance OR put two LEDs (with their resistors) in series? After putting two LEDs in series, I measured 9V or so across each LED, and the whole series runs something like 14mA (measured). So I'm assuming this won't kill the LEDs or pose a safety risk. Can you let me know what you think about this?
And lastly, how should I fuse 22AWG on 18.5V?
Thanks a lot in advance. I know I asked a lot of questions, sorry.
Here are pictures of the specs for the 3-12VDC box (the first one I talked about):
**broken link removed**
And here's the specs of the 18.5V box (it says 12VDC, but it measures 18.5VDC):
**broken link removed**
The first one is a wall charger that converts 100-120VAC to 3-12VDC. It has a 1200mA output max and is meant for being a universal charger. I can select different voltages, but I'm typically going to use 12V. My point is to use it for several purposes...
1) testing some 12VDC car things (such as LEDs and relay coils) to make sure they work before wiring them into the car. This makes it so that I can test stuff right in the house in the winter instead of freezing outside to use the car battery
2) to power some LEDs (with some switches) for home lighting. This is just for lighting up some small areas for seeing or decoration... hobby
3) to charge peripheral devices whose wall chargers are lost/broken or didn't even come with a wall charger. For a lot of my devices, I have car chargers but no wall chargers. So using the converter box, I can avoid finding/buying wall chargers and going outside to the car just to charge it.
So I have a few questions about using this:
- First is the fusing safety. I'm assuming that since its 12VDC, I would select the wire gauge/fuse value in the same manner as if I was in the car installing something. So I plan to use 24AWG with a 500mA fuse (probably much smaller than necessary). I feel safe with this. What do you think?
- Secondly, the box has an output-voltage selector switch. I can select 3V, 4.5V, 6V, 7.5V, 9V, and 12V DC. So my question is that since I'm not used to voltages other than 12V, if I was to use 9V (or something less than 12V), then would the fusing be the same? For ex, assume the max fuse size for 24AWG is 3A on 12V, but what would be the max fuse size for 24AWG on 9V? Would it go up or down? I'm typically going to use the 12V setting only, but I'm asking this just in case I ever decide to use a lower one. Would I be safe using the 500mA fuse on 24AWG for all the voltages?
- Using this box on the 12VDC setting, is it okay to test 12VDC relay coils (the kind I plan to use in the car) to make sure the relay works properly? I always test my relays before installing them in the car. The box wasn't really designed to power relay coils, so that's why I'm asking. I don't know much about inductive spikes and whether or not they can mess with the box. Of course the coil's current will be under the max limit.
That's all for the 12V box.
The second box I have converts the wall outlet to an 18.5VDC output. I wanted to power some LEDs with this box too. I know its not okay to power LEDs rated at 12VDC (they have resistors for 12V car 'plug n play') using the 18.5V box, but what if I add extra resistance OR put two LEDs (with their resistors) in series? After putting two LEDs in series, I measured 9V or so across each LED, and the whole series runs something like 14mA (measured). So I'm assuming this won't kill the LEDs or pose a safety risk. Can you let me know what you think about this?
And lastly, how should I fuse 22AWG on 18.5V?
Thanks a lot in advance. I know I asked a lot of questions, sorry.
Here are pictures of the specs for the 3-12VDC box (the first one I talked about):
**broken link removed**
And here's the specs of the 18.5V box (it says 12VDC, but it measures 18.5VDC):
**broken link removed**