How can I tell if four +5v pins are from the same source with a multitester?

[CZroe]

OK, I have a device that has four ports on it and each one has a +5v pin on it for powering a small electric motor. If, with a voltage regulator, I can get it to power a device that it was not intended to power, I'd like to know if it can power four of them.

So, if I wire two of the +5v wires together and then measure the voltage between that and a common ground, would I read +10v if they were from seperate power sources? Yes. I'm stupid. If it DOES measure 10v, is it safe to assume that if one of these can power the device that each of the others should be able to power one also at the same time considering that they are not using a shared power supply?

Thanks!

 

[TwoBills]

You would still only have 5v. If you series the devices, then you would have 10v. I'm thinking batteries here. If you have something like a rectifer that you're measuring I'd be careful connecting leads without a diode of some sort. Easier done than said.

 

[CZroe]

OK, if I can't tell that way then can I assume that if say port 1's +5v pin will ground to port 2's ground pin that the +5v in both ports are shared?

I really don't know what I'm talking about!

 

[Kwatt]

Originally posted by: CZroe
OK, I have a device that has four ports on it and each one has a +5v pin on it for powering a small electric motor. If, with a voltage regulator, I can get it to power a device that it was not intended to power, I'd like to know if it can power four of them.

So, if I wire two of the +5v wires together and then measure the voltage between that and a common ground, would I read +10v if they were from seperate power sources? Yes. I'm stupid. If it DOES measure 10v, is it safe to assume that if one of these can power the device that each of the others should be able to power one also at the same time considering that they are not using a shared power supply?

Thanks!

If you wire the +5v wires together and measure to a common ground you will get +5v's.


Most times when a power supply has multiple wires for the same voltage it comes from the same source. I.E. It's cheaper to build 1- 4 amp supply than to build 4- 1 amp supplies, usually. You also can build it in a smaller case.

If you can find out the total +5v power output of the power supply. You can then see if it is large enough to power what you need.

Look for a label that list Power Output: I.E. +5v @ xxxx milliamps.




Kwatt

 

[Kwatt]

Originally posted by: CZroe
OK, if I can't tell that way then can I assume that if say port 1's +5v pin will ground to port 2's ground pin that the +5v in both ports are shared?

I really don't know what I'm talking about!

You can assume that if you see sparks or smoke you assumed wrong.


Kwatt

 

[Kwatt]

Is this for the GBA project?

In the other post someone posted the GBA draws 350 milliamps 4x350=1400 milliamps.

What size electric motor was the power supply for?

If the power supply is a wall-wart type 1400 milliamps it is a good sized one.




Kwatt