Rogue MPT-3048 now available

I really don't understand what you're getting at Salvo. Are you trying to discredit Rogue or are you just asking questions?

mena661 wrote:
I really don't understand what you're getting at Salvo. Are you trying to discredit Rogue or are you just asking questions?

Mena, this has been going on for months if not years. Salvo just doesn't like the Rogue guy. The Rogue guy knows it. Gets old. :(

Salvo has been taking his civilization pills for quite some time now, and has been very helpful on a number of topics. I am especially grateful for some help in particular.

No idea why the Rogue guy gets up Salvo's nose. Just glad it's not me anymore with my "measurement errors." :)

Salvo wrote:
Never heard that gain error is greatest at full scale. Can you provide a link? Are you saying the gain error is nonlinear? The gain is probably set by a couple of resistors connected to the error amp. These resistors are not perfect. They have a tolerance that more or less defines the measurement gain error.

You're thinking of an op-amp, whereby gain is set is set via external resistors. Input bias current in that case certainly makes the response non-linear. With an ADC, the difference between offset error (measured with zero input) and gain error (measured at full scale) does normally cause a non-linear transfer function. I'll leave it up to you if you want to find a link for it.

The whole object of the amp & volt measurement specification is to determine what's the possible error when reading let's say 5.0A. Are you saying it's impossible to determine this error without measuring it? What's the purpose of your spec? What's does 1% at 100A mean? Max current is only 30A.

I'm guessing your current measurement error is at best 3 to 10% of reading plus +/- 0.1A. 0.1A is LSD, not offset.

Sal

No, the purpose (at least in my case) was to give a maximum figure, which is greatest at full-scale. The current sensors are good to 100a, so that's why 100a was chosen as the full scale figure.

0.1A would be the resolution. The LSD, by definition, could be any number from 0-9.

Sal, if you have any genuine critiques or questions, I'd be happy to entertain them. Nitpicking about non-issues doesn't qualify.

Salvo wrote:
For us 12V guys, peak efficiency is at 70W. Regardless of battery system, peak efficiency is located at the low end of the charging current range, between 5 and 10A.

Peak efficiency for most regulators (with the exception of some multi-phase designs) is normally at the lower end of the range. That's because resistive losses increase with the square of the current. Double the current (to 10a) and you're still at almost 97%, double it again (20a) at you're at 95.6%. Worst-case (30a) you're still at about 94%. You make it seem as though anything other than the sweet spot is going to be terrible -- which, in reality, is not true at all.

well, bottom line: is it a good product worth the money it cost?

j.p.f. wrote:
well, bottom line: is it a good product worth the money it cost?

I don't own one but their customers like it. At least that's what I have read (in other forums....not sure who owns one here). BTW, this one is a brand new model so probably not too many reviews yet. I was talking about their old one.

BFL13 wrote:

Mena, this has been going on for months if not years. Salvo just doesn't like the Rogue guy. The Rogue guy knows it. Gets old. :(

Salvo has been taking his civilization pills for quite some time now, and has been very helpful on a number of topics. I am especially grateful for some help in particular.

No idea why the Rogue guy gets up Salvo's nose. Just glad it's not me anymore with my "measurement errors." :)

Ok. Didn't know about the history. Thanks.

j.p.f. wrote:
well, bottom line: is it a good product worth the money it cost?

As noted, this is a new model, released a week ago after testing. Previous model 3024 had good reviews. With manufacturer being local, I don't expect much hassle with warranty - you won't have to ship it to China.

Assuming it is adequate for your system size and voltage - I don't see anything better at that price. The closest is MS45 with 50% more amps, 40% more money (if all same features are added), and blinking lights on the main unit. Or Bluesky 30 - same amps as Rogue, don't know about accuracy ;), and also more money.

mena661 wrote:
I don't own one but their customers like it. At least that's what I have read (in other forums....not sure who owns one here).

He does: this one. Posted a review a while ago, on FB and here.

lorelec
Nice looking new unit

A few questions
Do you publish the Power Net interface protocol?
If not why not?
I looked through the web site and was not able to find the protocol document

Good to see you mentioned the availablity of Multi-Phased units
At 30amps it likely adds too much additional cost with limited return, however anything above 30 amps multi-phased units do indeed offer efficiency increases throughout their operating current ranges.

From my POV the meter accuracy discussion is a non-issue so long as the meter reading is repeatable, which I assume it is

1. You define efficiency at a particular input and output voltage. What's missing is current.

I'm not knocking your actual efficiencies. They're great. It's just that the way it's presented is misleading.

2. The voltage and current measurement error spec is unconventional and useless. The displayed V & I measurements have significant errors. We went through this once before. The calculated output power was greater than the calculated input power. We know that's impossible.

Sal

lorelec wrote:


Sal, if you have any genuine critiques or questions, I'd be happy to entertain them. Nitpicking about non-issues doesn't qualify.