Golf carts used to be 36 volts. And moved to 48 volts.
A lot of electric scooter designs went with these voltage ranges as well.
And currently 36 to 60 V tends to be a good compromise with wiring weight (thinner wires for the same wattage with higher voltages) and reasonable costs for the required switching semiconductors. (Higher voltages, higher semiconductor costs)
Also, for bare, dry, intact skin, 48VDC is generally considered safe, I think by really old research.
When teaching Hot Process Safety, I’ve been informed that the “new” standard is 33V on bare, dry, intact skin.
Yeah, but still the convention. The reality is that any voltage can kill you under exactly the right conditions.
For some values of standard. It’s the same issue with a more conservative restatement.
The reality is, if you feel it, it’s dangerous even if it’s not fatal, and you can feel 12 V in most cases. The sensible approach is treat every wire as live and dangerous even if you ‘know’ they are not. No value in being dead wrong. It’s a bit paranoid, but they are out to get you. 
Did you mean to include a pic or link?
yea just added them 
Big ole multi voltage power supply, apparently 5, 7.5, 15 (maybe +/- 15V but probably not,) 18, and 24V Look like teh big current capacity is at 18V. Not clear what the 1-2-3 breakers are for. Might be that the 5V is for logic and has maybe 8 A current capability. Probably not work the size and weight for the output capability.
Hmmm I wonder what it could be used for… The transformer and capacitor looks dangerous. I might harvest them for my my induction forge. I have many odd things that I still don’t know what they are. Like this little guy
Looks like a 16 way RF power divider. Would need to sweep it to know frequency range if there are no part numbers on the 4-way dividers.
Iv tried looking up this but im not familiar with radios. Do you know what its purpose? Or should I ask the ham radio group? Ok last question 
I have 3 furnace blower fans and one starts smoking when I wired it so im assuming the insulation is toast, another one just needs a 277v power source, but the third one turns on but then turns itself off after a minute. It has two wires coming out of it and I believe its a red and blue… possibly purple (im color blind). It doesn’t have a capacitor attached to it and since i only see too wires, i assume it doesn’t need one. The motors label has long been weathered off but found a motor on eBay with the same number found on the motor (except for 5xbj025d cja ). The specs aof thats motor was ge 5xbj025d motor cw 230v 1/3hp 1725 rpm 48 frame
So the different colors are different speeds. Ie Hi, medium & low. Then you have your cap. The 277 one will likely not have multiple speeds, they typically use a rheostat. To change the speed.
This was originally used in an “in building coverage” cellular and LMR system. It was used to fill in coverage where the signal inside the building was inadequate. most large office buildings, hotel complexes and places like AA Ctr and Cowboy AT&T Stadium have them.
It’s just a part that takes an RF input and splits it equally 16 ways to feed 16 antennas or other parts of the system. .
But one of them only has two wires
This efficiency is considered in the panel rating, so you don’t consider it in these calculations. Panel efficiency sets how much panel area you need for a given power capacity.
I finally received the 850nm flashlight from aliexpress and unfortunately but not shocked, the flashlight is not rechargeable like it was advertised. it requires a 18650 battery which technically is rechargeable haha. Now im wondering how to wire it to my vehicle. Should I eliminate the battery or keep it. I do still intend to add a toggle switch and possible relay… Any suggestions on how to wire this to my vehicle? specs: 10Watts 3.7V-4.2V
The battery is a fire hazard if not charged exactly right, so I’d ditch it. Find a dc-dc converter that’s rated for at least 2 amps and power it with that
