amperage requirements?

[the_doc735]

measured again:

this time:

   ....the peak at boot up time, with the clamp set to 2A/DC I get: (display count 2000) EXACT SAME SETTINGS AS BEFORE!

3.3v /0.463

5v /0.346

12v /0.2??

 

...a bit different to the first test! I did each of them several times over!

 

 

...when the 'ZERO' function is activated (and it is displayed as active on the LCD) the readings are a lot lower than this.

 

I don't suppose using a cardboard template to centre the cable will affect the result?

 

 

[the_doc735]

addendum:

 

does it matter that the clamp is close to the other 23 cables that go to the 24 pin ATX plug on the mobo?

see previous post with pic.

cheers!

[Shadders]

Hi,

No, the cardboard template will not affect the device operation. The other cables will have an effect - but this should be minimal to non-existent.

Regards,

Shadders.

[Superdad]

If you really want an accurate measure of current draw, then cut the wire and put a fast multimeter/ammeter in series with the circuit. 

[the_doc735]

1 hour ago, Shadders said:

Hi,

No, the cardboard template will not affect the device operation. The other cables will have an effect - but this should be minimal to non-existent.

Regards,

Shadders.

would it be worth getting a clamp meter with the MAX./MIN. function?

[Shadders]

2 hours ago, the_doc735 said:

would it be worth getting a clamp meter with the MAX./MIN. function?

Hi,

I do not think so - if you run many applications which is worst case - then you can see the maximum current. The surge at turn on is just that, a surge that decays to the steady state. Most power supplies do this - since all circuit capacitance etc., is uncharged, and the surge is charging the motherboards capacitors etc.

 

Regards,

Shadders.

[gstew]

4 hours ago, Superdad said:

If you really want an accurate measure of current draw, then cut the wire and put a fast multimeter/ammeter in series with the circuit. 

Many of these meters will also have a peak-hold function. When I DIY'd an ATX-24/P4 linear motherboard supply a few years back I did exactly what @Superdad suggested with a meter that captured the peaks. Gave me exactly what I needed. 

 

Greg in Mississippi

[Tomslin]

As I can see you are doing an improperly measuring. Because you can’t measure one leader individually when there are several that are in parallel. Probably your current ATX connection is done in this way, with several parallel leads for each voltage. And of course the current flow will be smaller in each one than in all leads together. Nothing strange with that.

[the_doc735]

9 hours ago, Tomslin said:

As I can see you are doing an improperly measuring. Because you can’t measure one leader individually when there are several that are in parallel. Probably your current ATX connection is done in this way, with several parallel leads for each voltage. And of course the current flow will be smaller in each one than in all leads together. Nothing strange with that.

@Superdad  "If you really want an accurate measure of current draw, then cut the wire and put a fast multimeter/ammeter in series with the circuit."

@paulhynes  "To actually measure the rail power would require inserting a low value resistor in series with the rail output, then measuring the voltage drop across the resistor"

All a little confusing (perhaps contradictory?)   ...all these are answering the same question; are these all valid different methods perhaps?

@Tomslin  ...could I bunch/group these altogether by voltage? all 3.3, all 5, & all 12v into 3 single cables, something like this:

...in this case clamping on the single transparent wires @ the far left of the pic? Would that be better please?

Cheers!

 

[Shadders]

Hi,

Yes - as per others have stated - if you have multiple wires which are being used - then you must measure all to obtain an accurate reading of the current drawn from each voltage.

 

From your picture, you have broken the single power wire into multiple, so you must measure the single wire before it is broken out.

 

Regards,

Shadders.

[Tomslin]

I’ll try to be more concise: All cables for the same voltage rail (same color) should get into the clampmeter. Then you get a correct measuring value of current for each rail or line to your motherboard. Of course also depending to the accuracy of your instrument.

If you choose to measure only one cable as you did before, you must multiply that value by the number of cables.

[the_doc735]

OK,

 

I grouped the cables together: (peak/boot) set to 2A/DC on clamp:

 

all 3.3v (4) 0.663A

all 5v (5) 0.470A

all 12v (2) 0.300A

 

...total = 1.433A

 

 HDPlex: 'Larry' said: "I don't think so. 12V boot peak would at least be 1 - 1.5A. This seems too low."?

 

...did each a few times.

[Tomslin]

This values doesn’t seem likely, they are too low. Instead measure each cable individually and then sum the values and see what it will be then. Btw, you measuring during peak/boot? Why do you doing that? I suspect it are short-term conditions that can be hard to measuring correctly.

[the_doc735]

1 hour ago, Tomslin said:

This values doesn’t seem likely, they are too low. Instead measure each cable individually and then sum the values and see what it will be then. Btw, you measuring during peak/boot? Why do you doing that? I suspect it are short-term conditions that can be hard to measuring correctly.

OK, I'll sum the values tomorrow and put the results up then.

Yes I am measuring the peak/boot & once I get that 'sorted', I also need to measure @ idle and under normal 'music/audio' load conditions. This is at the request of people like paul hynes, sean jacobs, Larry (HDPlex), T Pardo, etc. I may be in line for 'a build' from any of these depending on price but they won't given production price without accurate current draw/load/ amperage figures.

Many thanks!

[Tomslin]

I haven’t read this thread from the beginning so I thought your intention was something about DIY.

But now, your reason for doing these measurements, as you explained here, seems quite strange as I see it. I mean, why should you as a not professional builder/designer, serve them with these rather advanced measurements? I don’t see it as a sensible reason to make such advanced measurements just to get a price. You will probably pay expensive for the product in any case. It's not any rocket research behind to build a power supply to a computer, although some may want to make you believe it. Put there a pico-psu, you can power it from a regular 12V car battery, then measure the actual current draw during to the worst power conditions to the pico, and it's done. Also don't hurt to tell what things you have in your computer. If they not can build you a good power supply after this, I would be really surprised. Then I’m also grateful for an explanation

[the_doc735]

23 minutes ago, Tomslin said:

I haven’t read this thread from the beginning so I thought your intention was something about DIY.

But now, your reason for doing these measurements, as you explained here, seems quite strange as I see it. I mean, why should you as a not professional builder/designer, serve them with these rather advanced measurements? I don’t see it as a sensible reason to make such advanced measurements just to get a price. You will probably pay expensive for the product in any case. It's not any rocket research behind to build a power supply to a computer, although some may want to make you believe it. Put there a pico-psu, you can power it from a regular 12V car battery, then measure the actual current draw during to the worst power conditions to the pico, and it's done. Also don't hurt to tell what things you have in your computer. If they not can build you a good power supply after this, I would be really surprised. Then I’m also grateful for an explanation

If you read the entire thread you'll see that I haven't mentioned DIY?

One explanation from Paul hynes is that the power requirement will affect the parts like the case and heat sinks for dissipation etc. The lower the power requirement, then the smaller the case, the smaller transformers etc. Conversely, the more powerful and bigger the PSU the more it will cost, so if I have those figures I can tailor it precisely for its purpose; if I don't have those figures I would have to massively over specify the PSU and as a consequence the final cost would be considerably more.

Similar comments from others, but more modifying what they already have available rather than a complete build.

I don't see how measuring the load to a pico from a battery would help me get the 3.3, 5, 12v load measurements though?

My third post in this thread lists the components in my PC.

I'm sure they can build good PSU's that are suitable for my purpose once they have the correct info.

I haven't ruled out DIY yet though. 

[Superdad]

1 hour ago, the_doc735 said:

I'm sure they can build good PSU's that are suitable for my purpose once they have the correct info.

Who is "they?"  I don't see any reference here in this thread to who might be willing to build you a full custom multi-rail ATX LPS.  And are you prepared to pay the price?

[the_doc735]

2 hours ago, Superdad said:

Who is "they?"  I don't see any reference here in this thread to who might be willing to build you a full custom multi-rail ATX LPS.  And are you prepared to pay the price?

As I already said above: "people like paul hynes, sean jacobs, Larry (HDPlex), T Pardo, etc."   ...some are mods. of gear they already have, others are 'ground up' builds. Others are: Kenneth Lau, John Wood, Paul Baldwin, Paul Pang. No they are not all ATX LPS, but serve the: 3.3, 5, 12v requirements. I don't know if I am prepared to pay the price until they come back with estimates/quotes. I haven't ruled out DIY at this stage though.  

This is more probing stuff that doesn't answer my original question, which nobody seems to know? That's why I am trying to find out my self with research and spending time and money on measurement equipment like clamp meters.

I wish I could afford your LPSU's but it's a little beyond my price range unfortunately. Never seems to be any decent secondhand ones hanging about out there!

[the_doc735]

33 minutes ago, the_doc735 said:

As I already said above: "people like paul hynes, sean jacobs, Larry (HDPlex), T Pardo, etc."   ...some are mods. of gear they already have, others are 'ground up' builds. Others are: Kenneth Lau, John Wood, Paul Baldwin, Paul Pang. No they are not all ATX LPS, but serve the: 3.3, 5, 12v requirements. I don't know if I am prepared to pay the price until they come back with estimates/quotes. I haven't ruled out DIY at this stage though.  

This is more probing stuff that doesn't answer my original question, which nobody seems to know? That's why I am trying to find out my self with research and spending time and money on measurement equipment like clamp meters.

I wish I could afford your LPSU's but it's a little beyond my price range unfortunately. Never seems to be any decent secondhand ones hanging about out there!

   ....SOtM stuff is also expensive, as is Innuos, & mojo audio. 

[Tomslin]

6 hours ago, the_doc735 said:

If you read the entire thread you'll see that I haven't mentioned DIY?

One explanation from Paul hynes is that the power requirement will affect the parts like the case and heat sinks for dissipation etc. The lower the power requirement, then the smaller the case, the smaller transformers etc. Conversely, the more powerful and bigger the PSU the more it will cost, so if I have those figures I can tailor it precisely for its purpose; if I don't have those figures I would have to massively over specify the PSU and as a consequence the final cost would be considerably more.

Similar comments from others, but more modifying what they already have available rather than a complete build.

I don't see how measuring the load to a pico from a battery would help me get the 3.3, 5, 12v load measurements though?

My third post in this thread lists the components in my PC.

I'm sure they can build good PSU's that are suitable for my purpose once they have the correct info.

I haven't ruled out DIY yet though. 

 

Do you think I’m stupid? I am fully understand the technical aspect behind a build of a power supply. It all looks like more a school assignment than a case where you are in touch seriously with these designers. Will they also participate in this thread? And you even didn't know how to use a clamp meter for making a serious measurement. Very, very strange...

[marce]

Its a PC, not exactly designed to be the lowest noise device on the planet, so whatever you put in front of it is not going to make much difference...

[4est]

5 hours ago, Tomslin said:

 

Do you think I’m stupid? I am fully understand the technical aspect behind a build of a power supply. It all looks like more a school assignment than a case where you are in touch seriously with these designers. Will they also participate in this thread? And you even didn't know how to use a clamp meter for making a serious measurement. Very, very strange...

Now you are catching on!

[the_doc735]

17 hours ago, Tomslin said:

 

Do you think I’m stupid? I am fully understand the technical aspect behind a build of a power supply. It all looks like more a school assignment than a case where you are in touch seriously with these designers. Will they also participate in this thread? And you even didn't know how to use a clamp meter for making a serious measurement. Very, very strange...

no I don't think you are stupid. I know from your posts that you are very knowledgeable in this area. But you asked what a quoted price had to do with amperage and other specifications, I am simply answering your question with comments I have received from the builders themselves. It is your prerogative to think that I am not in contact with, or have never made contact with any of these builders, that is your choice, mind you I don't know what evidence you have to suggest that assumption? How could you possibly know that? It is up to those designers if they wish to participate in this thread, not me. I don't see any shame in not having used a clamp meter before and researching how to use it, I don't feel inferior in any way just because this is the first time I have used a clamp meter, what's wrong with learning how to use a device?

[the_doc735]

15 hours ago, marce said:

Its a PC, not exactly designed to be the lowest noise device on the planet,

I know that!

 

...."so whatever you put in front of it is not going to make much difference..."

plenty would debate this I think?

[the_doc735]

22 hours ago, marce said:

Its a PC, not exactly designed to be the lowest noise device on the planet

Please remember even the innuos zenith SE has a supermicro mobo that can be used as part of a conventional PC! AND it uses a LPS technology, not SMPS. That is classed as a dedicated Hi-Fi device; so it's still a computer and it's used for audio/music. That's just one example that promotes the use of LPS technology in hi-end audio.