Accuracy of clamp on ammeters?

[MOPAR3]

I didn't realize you could measure small currents with a clamp on type meter. I run currents up to 10amps right through my meter and use the clamp for bigger stuff.

[devnull]

This is what I appreciate the most here on AK -- the wealth of knowledge people have and their willingness to share it!

Originally Posted by Blast

Your 2246 scope is a blast from the past! I repaired many VCR's with that model throughout the 90's! I had all the common settings saved in memory.

Heh...well, I'm sure the scope has the capacity to do plenty of things. Presently its biggest limitation is me! That'll change in time, though.

Originally Posted by 33&athird

Very cool scope, you can't go wrong with a tektronix...should last you for many years. If you want something cool to do with a scope, connect one channel to one channel of an audio signal, and channel 2 of the scope to the other. Connect the ground to the audio ground. This will display exactly what the signal looks like. Not only is it a cool show, you can play around with settings and figure how to operate it. Plus, it's free...and as long as you use reasonable ac voltage, you should not run a risk of damaging anything.

I'll have to check that out. As of yet there isn't very much I have done with it, but that sounds like something simple enough to do.

I like velleman kits as well, nice variety, good prices, and neat results.

I've yet to order one. I am thinking I want to pick up a variac and the aforementioned ammeter first. Velleman does offer some very interesting kits, though. I might just go ahead and order one. It's not as if a variac is necessary for one of those kits.

I wish I had information about clamp-on ammeters, but I honestly have no idea how they work, I guess i'm old-fashioned, in that I perfer standard meters. Though I will admit the features on that oscilloscope are awfully nifty.

Either way, you are on the right track to an excellent work bench!...good luck, I hope you enjoy it .

Thanks! Just like in any other trade or hobby, the quality of the tools involved are an important factor. (and of course, the ability to utilize them properly)

Originally Posted by whoaru99

I have a Fluke i1010 current clamp accessory. 1A-600A AC, 1A-1000A DC, 2%+0.5A is what the spec says.

If lower current is your thing, there is something like the i30 which is up to 30A AC or DC, with 1% +/- 2mA.

So, they can be pretty good given the convenience.

The Kill-A-Watt is a pretty nifty device, but it doesn't have very fast response to get a peak/inrush/glitch type reading.

I'm thinking I could very well end up with both in the long run. I'm gathering recommendations of those that have worked with these units to get started, and with some experience determine what works for me in the long run.

Originally Posted by ken kantor

http://www.eurekaspot.com/webdata/appnote/1603.PDF

IMO, the Tek 2246 is one of the finest scopes ever made. Yeah, higher freqs are sometimes needed these days and digital capture helps for complex signals... still it's often my 2246a or 2247 that gets used for design or repair work. Congrats! (For tube amp use, you are probably going to want a couple of x100 probes, or a differential input box).

I have been doing research off and on over the last year as to these scopes, and found they had a pretty good reputation overall. Looked like a good scope for what I thought I would need.

A computer and external "sound card" can make a very flexible audio generator. If you prefer a stand-alone unit, there are a few ways to go. I would avoid the cheapie, $100, "function generators" with lots of bells and whistles. They can do tricks, but the waveforms are usually not very clean.

Here's a simple, stepped audio generator that is very useful. It's primitive, but the sine wave is very clean, (typically better than 0.005% THD) This can be good if you are measuring or listening for distortion.

http://www.allspectrum.com/store/pro...roducts_id=733

Next step up, (and my recommendation), would be:

http://www.testequipmentdepot.com/in...-809and810.htm

then...

http://www.proaudio.com/product_info...oducts_id=4833

Finally, if you really want to look at dynamic amp power, do complex sweeps and that kind of thing:

http://www.rigolna.com/products_dg10X2.aspx

For a learning kit, here's a fun and useful one:

http://www.qkits.com/serv/qkits/vell...ages/k4301.asp

-k

Cool!

I'm still doing some reading on the various options out there, and wondered about the cheap function generators I saw listed on that auction site. The concept of 'if it is too good to be true, it probably isn't' came into play, leaving me skeptical as to their quality.

The sound card signal generator might be the route I go initially, although I would definitely prefer a dedicated unit. That Instek unit looks pretty nice. It'll probably be a few months before I pick up a signal generator. Perhaps sooner if a few things fall into place.

Originally Posted by westend

Timely stuff. I just acquired a Textronik 454 from another AK'er. I have been too busy with projects to sit down and really see what it can do Thanks for all the links, Ken.

Devnull, I have a Fluke 36 clamper and it does a fairly good job with current, mostly used for residential wiring projects. Your scope is going to outperform it by a long shot for electronic work.
If you're looking for an amp build, you could join the F5 party. There are now more than a half dozen AK'ers that have built or are building these Nelson Pass amps. If you're looking for a simpler project, there are a lot of chip amp projects out there. I can't comment on any but the Tripath or T-amp, it is an amazing little amp. Since it is powered by 12v., there are a number of ways to power it and the amp board is very small. There have been thousands of builders and modders that have used the Tripath amp board so it is well supported and information is plentiful. Good luck with your new scope and your amp projects.

I've checked out the threads on the F5, and that very well could be a project I pick up. I definitely need something on the simple side o' thinks initially to get the ball rolling, which is where one of those Vellemen kits comes in. That will provide a little of the 'hands on' experience for which there is no replacement. Ya know, I haven't looked at one of those Tripaths, I'll have to check them out.

Something that is cool about the F5 projects is the diversity in them, that being the various enclosures used. The enclosure you chose for your F5 looks great! I'm sitting here entertaining thoughts of some custom plate aluminum enclosure with complex curves. Hmmnn...me thinks my case would cost far more than anything else on the amp! Eh, I designed tooling for 17 years, and in that field, no one cares what something looks like. Well, for the most part, that is. I worked for a tool shop that produced die cast dies for GM, Ford, and Chrysler. There was attention paid to what they looked like, as it was felt it reflected the quality of the dies themselves. That wasn't common, however, and for what those dies cost, they should have looked like works of art.

But I digress -- the ability to design your whole amp the way you want it looks like a hell of a lot of fun!

Thanks for the replies!

John

The cool thing about those F5 projects is the diversity among them.

[d3imlay]

If you want to measure line current a 10amp inline meter is fine. I've used the same one for 25 years. I built up a power supply in a rackmount enclosure.

Attached is a schematic and a picture. The power supply is the one at the bottom of the rack. Incidentally, the rack system has paid for itself hundreds of times.

[tensleep]

http://www.alliedelec.com/Search/Pro...0169&DESC=BD35

This meter is powered off of line voltage and will provide many functions. It may be way more that what you are looking for, but it would make a very nice built in diagnostic tool. You can even capture data to a computer!



Here is a much more reasonable meter than the first one I posted. While I would love to have something like that to fool around with, it is definitely overkill, especially considering the scope of your project. This one, while still a bit pricey, is in line with what you are doing. In fact, I have ordered one for myself! My garage is still acting as a storage unit (just moved in), so I have yet to play with it.

http://www.alliedelec.com/Search/Pro...IV-R#tab=Specs