Some questions about power analyzers

[HKJ]

Do any of these plug-in-a-plug Kill-A-Watt type devices have USB or any other way to pull data over to a PC? And can any/all of them give instantaneous current draw and/or peak current draw? Those two values seem like two of the things I'd be most likely to be interested in more frequently.

Something like this: https://www.banggood.com/AT3010-AC50~320V-100A-3KKW-Phone-App-AC-Meters-Digital-Voltage-Meters-indicator-Power-Energy-Meter-Voltmeter-Ammeter-Current-Amps-Volt-Wattmeter-Tester-p-1390443.html?cur_warehouse=CN&ID=558071 can. It do not support peak measurement, there you need a real power analyzer.

TestController https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/ is supposed to support it (I do not have the device to verify).

[_Wim_]

  Here's a cheap used one that works. https://www.ebay.com/itm/203019478378?hash=item2f44e7656a:g:ywsAAOSwiE9e44WO Yes, that's a floppy drive on the right hand side.

  Here's another of the same model with with the display shown. But this one is being sold for "parts" so it's not guaranteed to work. https://www.ebay.com/itm/153285701784?hash=item23b08a3098:g:UukAAOSwAQVcArcm

  A Kill-A_Watt isn't much of an analyzer but if you just want to see how much power you're pulling at the moment or the line voltage, they're good to have. 

 

Be aware that with these you need  separate current probes to measure current. This is different from the Voltech/Yokogawa units which typically have an internal current shunt.  They are however nice units.

[_Wim_]

Do any of these plug-in-a-plug Kill-A-Watt type devices have USB or any other way to pull data over to a PC? And can any/all of them give instantaneous current draw and/or peak current draw? Those two values seem like two of the things I'd be most likely to be interested in more frequently.

Something like this: https://www.banggood.com/AT3010-AC50~320V-100A-3KKW-Phone-App-AC-Meters-Digital-Voltage-Meters-indicator-Power-Energy-Meter-Voltmeter-Ammeter-Current-Amps-Volt-Wattmeter-Tester-p-1390443.html?cur_warehouse=CN&ID=558071 can. It do not support peak measurement, there you need a real power analyzer.

TestController https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/ is supposed to support it (I do not have the device to verify).

Wow, that is indeed a very affordable solution! So no excuse any longer for not having a power meter when doing test equipment repair! 

[mindcrime]

Do any of these plug-in-a-plug Kill-A-Watt type devices have USB or any other way to pull data over to a PC? And can any/all of them give instantaneous current draw and/or peak current draw? Those two values seem like two of the things I'd be most likely to be interested in more frequently.

Something like this: https://www.banggood.com/AT3010-AC50~320V-100A-3KKW-Phone-App-AC-Meters-Digital-Voltage-Meters-indicator-Power-Energy-Meter-Voltmeter-Ammeter-Current-Amps-Volt-Wattmeter-Tester-p-1390443.html?cur_warehouse=CN&ID=558071 can. It do not support peak measurement, there you need a real power analyzer.

Not having built-in peak detection isn't a big deal, if you can pull the data to a PC, at least if the sample rate can be fast enough. And for me,  a sample rate of once every 500 milliseconds or so, or even once a second, would probably be fast enough.  You can always do the peak detection in software. I may just buy one of these and have a poke at it and see what it can do. It's cheap enough to be worth taking a flyer on at the very least.

[JeffK]

2. Spend a little bit more for a Voltech that's listed as being in working shape. If I went this route, do you folks have any opinions on what a good price would be for for, say, a PM3000? Or if there's another model you recommend, what a good price would be for one of those?

4.Something else altogether, depending on what you lot tell me. Since I "don't know what I don't know", I'm probably missing some really obvious options here. Fluke and Hioki seem to be significant players in this space as well, so maybe something (new or used) from one of them? Other?  Any and all suggestions or input are greatly appreciated.

I see that being able to observe the power consumption of a device even when it's not displaying any obvious activity could be useful for debugging something that's misbehaving. And now that I'm thinking about it, I can imagine other times when you would want to know details about the power consumption of a device. So now a power analyzer seems like something that I could use, although clearly not something that would get used every day.

Voltech has made some very good products but ever since Tektronix assimilated them sometime around 2013, they seem to be only focused on supporting newer products. Not unreasonable for Tektronix to keep their business afloat but finding schematics and firmware for out-of-date products can be a challenge. I previously owned a PM3000A for making 3 phase measurements. I found it to be a useful tool but getting factory support was very difficult. Unfortunately on the PM3000A, I found their PC software and communication options to be amateurish (to be kind, it was designed in the 90s). Luckily all of the measurements I needed were available on the Instrument VFD display. 

Here's a good teardown video on on the PM3000A -      

As several have pointed out here and other posts, the Kill-A-Watt product is good at what it does for the price point. No surprise a $40 instrument rated to measure up to about 1875VA has difficulty making accurate measurements in the single digit or fraction of a watt range. Probably not the ideal tool for debugging low power electronic loads that are misbehaving.   

If you can find them used, the Gossen 29S or Gossen Metrahit Energy hand held meters would be a good candidate. Easily and accurately measure down into the milliwatt range for standby power measurements, even at 240vac. And with data logging capability and USB communications. The Gossen 29S was sold in the US by Dranetz as the PowerLogger10 meter. Here's one available available on eBay.  https://www.ebay.com/itm/124696556890   See Dave's video #173 for a teardown video on the Gossen Metrahit Energy. 

The Yokogawa WT series bench top power meters are some of the better Instruments available with several communication options. Look for the teardown post by D Straney on this blog. You should be able to find a WT210 in good working order used for a similar price to the Voltech products. If you intend to use the free software available from Yokogawa, then make sure you verify the WT210 has at least firmware version 1.11 or later. 

One of the more useful features of the WT210 is the wideband capability of up to 100khz with excellent common mode rejection. Can be useful to measure power losses of inductors or transformers in power conversion circuits. Also useful to measure power in the motor windings of a PWM motor drive. The Watt-Hour integration function is also quite useful to measure the power conversion efficiency of intermittently loaded AC to DC power supplies and battery chargers. 

Here's a good video from Fairchild semiconductor on measuring switch mode power supplies in practice using a WT210.