There's this thing called the laws of physics. The output rails of an ATX PSU have massive amounts of capacitance on them. This means that the output voltage simply can't change that fast.
Just out of curiosity, have you ever used an 87V?
No, you have capacitances of several thousand uF in every PC power supply. The Corsair AX you mentioned?
What do you think the big cylindrical things are on the right side?
My point still stands, the 87V can reliably measure the quality of AC and DC power supplies and detect faults using its Peak Min/Max mode.
No, you have capacitances of several thousand uF in every PC power supply. The Corsair AX you mentioned?
What do you think the big cylindrical things are on the right side?
Not sure if serious.
Think at least twice before to post, those are DC BUS capacitors just after PFC stage
Secondary rails (5V, 3V3) DC/DC converters are on the right side of the picture on vertical PCB boards, including the one carrying output connectors, they are working at hundreds of thousands of Hz, please find those alleged "thousand uF" capacitors on their outputs and show us their images.
My point still stands, the 87V can reliably measure the quality of AC and DC power supplies and detect faults using its Peak Min/Max mode.
Good luck.
Thanks to this post your perceived competence on switched power supply dropped near zero.
Thanks to this post your perceived competence on switched power supply dropped near zero.
... and the accompanying mouth.
You should retract that statement. Else I will ask a moderator to.
1 Gohm? That's insane. What are the practical applications for this?
As long as we're talking Fluke and Brymen, anyone want to weigh-in with any experience with, or thoughts on, the Fluke 115 vs. the Brymen 257s? [...] Brymen seems to be equivalent or wins on most specs.
The killer features of the 87V:
- 250us peak min/max. It's hard to convey in words how awesome this feature is. This means the meter can replace an oscilloscope in many scenarios.
- 8V diode test. 'Nuff said. No other meter does this.
- No backlight timer. Once you turn it on, it stays on. This shows a deeper philosophy. The Fluke engineers assume that the users are people who know what they're doing, not senile old women.
Also:
Used Fluke 87Vs are all over eBay, used Brymens on the other hand, none.
I wonder if you really wacthed those videos, the truth is there, no weird things with high res mode engaged, the BRYMEN has one digit more than 87V and it's working good for tendency monitoring, you have to accept it.
Very limited real-world use. Say I remove the charge current from a battery. I know what's going to happen. The voltage is going to drop slowly. It's not going to go up. I don't need a meter to tell me that. If I want to measure how fast it drops, 4 1/2 digits are plenty enough.
No, it clearly shows the engineers didn't think the design through. Either that, or they just didn't gave a shit. Wait, maybe that's the reason they design a backlight that makes an annoying high pitched sound. How can you rely on a meter that does weird, unexpected things?
If you think these show how Brymen is uncapable, how do you explain away Fluke's blunders, with some of them being way worse than this?
I don't know why no one ever mentions other uses for the resolution other than watching a battery discharge, but the 500k counts mode sees regular use on my BM857. For once, it provides µV resolution on the mV range, and it worked great for monitoring the output of Wheatstone bridges for example. I also use the meter fairly often to match resistors, although it's only 50k counts in that mode. I have never had a need for the crest/peak function though. So I guess we can agree that different people want different features from their DMM.
Uh, what? Not rounding introduces a maximum error of 0.9 count or ~.002% FS on a meter that has a .02% + 2 counts DC accuracy. It may not be the proper way to handle the 500k/50k conversion, but it's impact on accuracy is negligible. The backlight noise issue is also blown way out of proportion, as it's a minor annoyance at most and has no impact on performance. If you think these show how Brymen is uncapable, how do you explain away Fluke's blunders, with some of them being way worse than this?
I wonder if you really wacthed those videos, the truth is there, no weird things with high res mode engaged, the BRYMEN has one digit more than 87V and it's working good for tendency monitoring, you have to accept it.
Very limited real-world use. Say I remove the charge current from a battery. I know what's going to happen. The voltage is going to drop slowly. It's not going to go up. I don't need a meter to tell me that. If I want to measure how fast it drops, 4 1/2 digits are plenty enough.
I don't know why no one ever mentions other uses for the resolution other than watching a battery discharge, but the 500k counts mode sees regular use on my BM857. For once, it provides µV resolution on the mV range, and it worked great for monitoring the output of Wheatstone bridges for example. I also use the meter fairly often to match resistors, although it's only 50k counts in that mode. I have never had a need for the crest/peak function though. So I guess we can agree that different people want different features from their DMM.
No, it clearly shows the engineers didn't think the design through. Either that, or they just didn't gave a shit. Wait, maybe that's the reason they design a backlight that makes an annoying high pitched sound. How can you rely on a meter that does weird, unexpected things?
Uh, what? Not rounding introduces a maximum error of 0.9 count or ~.002% FS on a meter that has a .02% + 2 counts DC accuracy. It may not be the proper way to handle the 500k/50k conversion, but it's impact on accuracy is negligible.
I am trying to stay out of this fan boy fight, but.....
Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.
The reason why no one ever mentions other uses is because resolution is not accuracy. The accuracy is specced at 0.02% +-2 digits, the digits referring to the 50.000 count reading. Example: you're measuring a 5.00000V precision reference. The 869s could be displaying anywhere from 4.99880 to 5.00120. Those extra digits are nothing more than a gimmick.
I am trying to stay out of this fan boy fight, but.....
Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.
Except, saying it's personal preference is a meaningless statement. We're not talking about shirt colors. Why do you prefer one over the other? That is the question. So far, a lot of the rationale of the pro-Brymen crowd has been based on something other than fact.
I am trying to stay out of this fan boy fight, but.....
Both companies and meters have their benefits and draw backs. One can pick the ONE unique thing that matters to you and make that the most important thing if you want. That does not make it the most important thing to others just because you said so. Each has their own preferences. Some people prefer a longer warranty, some prefer a lower price. Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.
Except, saying it's personal preference is a meaningless statement. We're not talking about shirt colors. Why do you prefer one over the other? That is the question. So far, a lot of the rationale of the pro-Brymen crowd has been based on something other than fact.
Some prefer a longer history, some prefer a better feature set. Some prefer Fluke no matter what. Each can be happy with his own decision. The point of the original question is why buy one over the other. It comes down to preferences.
A lifetime warranty for Fluke is a fact for some.
You buy a (used) Fluke over a Brymen because if you buy a good model at a fair price (such as an 87V) you can use it for 10 years and as long as you haven't killed it you can resell it for what you paid. Try that with a Brymen(or almost any other "B" brand.)
QuoteYou buy a (used) Fluke over a Brymen because if you buy a good model at a fair price (such as an 87V) you can use it for 10 years and as long as you haven't killed it you can resell it for what you paid. Try that with a Brymen(or almost any other "B" brand.)
Really? You can buy a used Fluke and sell it for the same price 10 years later? Is that including inflation? I would love to see proof of this either way.
Some factual reasons why someone may prefer a more expensive Fluke 87V:
Low burden voltage
Hi Z mode
High diode test voltage
Frequency trigger on +/- slope
Smoothing option on display
Backlight on/off switch with intensity control
Bargraph zoom mode
Peak Hold 250uS
Standard hold and auto Hold
Battery life 400 hours
High voltage warning on display
IP30 rating with 1 meter drop test
Long warranty period
Easy after sales service