Testing equipment needed for electrolysis R&D

[pertyfly]

Everyone,

I would like to know where to get some good used inexpensive electronic equipment. I am really looking for a good signal generator device for testing frequencies on my electrolysers. Even information would help me. I would like to know what type of unit would be best used for this purpose, and what specs I should be looking for specifically (I understand there are different units designed for different purposes, and frequencies, voltages, etc) Is there anything importand I should know? I do have a fairly good electronics background, but nothing really great.

I looked in my area for gov't auctions, etc and there is not really anything good. (Canadian government, you know....We use all of our things until they are 50 years old and become unusable..I mean look at the vehicles we sent out to Iraq for peace keeping...look at our military....enough said)

So, now I am not sure where to get anything like this really without spending a fortune. Anyone in the area know of anywhere?

Even if I could get decent equipment, and have it shipped.

I'm not sure really building a circuit with adjustable frequencies, voltages, etc would be accurate enough (or cost/time effective enough) to play around with in experimentation unless I've already found the approx. area of freguency I'm looking for.

I am also in need of an oscilloscope, etc. Anyone have any of these for sale?? hehe

Any suggestions would be appreciated. Thanks!

Chris

[nakros]

Pertyfly,

Ebay is probably your best bet.

Another good opportunity, if you can find them, are out-of-business sales and auctions (should be quite a few in around Toronto) -- Look through some of the online auction lists for upcoming auctions -- I guarantee you'll find some equipment that will help you out.

I'm in the Ottawa area, so if I happen to see any auctions that will have electronics or testing equipment, I'll let you know.

[pertyfly]

Thanks for the info....I'm also wondering of what manufacturers to look for. Are there really companies that make these sort of devices that are too cheap to be of use? (like for all other electronic devices)

[thrival]

Pertyfly:

Your thought process seems to be running towards hardware;
may I suggest software instead? There are freeware
programs for turning your computer into a signal generator
and O-scope, mostly in the audio-band. (Obviously you own
a computer, so why incur further expense?)

Here are a few links:

http://www.messaggeri.it/xmisuretest.htm

http://www.sss-mag.com/swindex1.html#rf

http://www.packetradio.com/freeware.htm

http://www.daqarta.com/DG_CONT.HTM

http://www.dazyweblabs.com/shannonsoft/page3.html

Freeware oscilloscopes & frequency generators are common.
Actually there's so much stuff out there I haven't had time
to install and review a bushel of programs I've saved. I'm looking for a
frequency analyzer in the 0 - 20MHz range. If you find one amidst the links, would you let me know?

[pertyfly]

Hey, thanks for those links....

I was thinking about this earlier today, believe it or not, because I have programmed computers in the past to communicate through the parrallel port and to operate equipment, etc

I just don't see how it can power anything I can use at this time reliably. I mean, I understand it can create those signals and things, but without enough power. I realize I can go through some simple circuits to just take it as an input possibly in order to generate a higher power with the external circuit. I just don't know with all the circuitry how accurate the signals will be. I haven't looked at the sites yet, but will as soon as I get a chance. Another problem is I'm looking for quite a low frequency. I'm really not sure the SW can do what I need it to do, but if so I will be quite happy.

[thrival]

pertyfly:

Some of the software sig-gens have accuracy to .00 decimal points
so low frequencies should be no problem.

Just use a car battery thu the collector of a transistor to ground, and power
the base from your soundcard-- simple.

[pertyfly]

Any suggestion for a transistor on this type of application?!? I don't know how large it would have to be for electrolysis type current...We're usually talking about mA with the transistors I'm used to

I dunno, maybe I'm overlooking something here, but I do get the concept.

[thrival]

pertyfly:

If the gain from one transistor isn't enough, try a darlington pair, before going to a full-blown amplifier circuit. Power transistors like those found in older sound system power amps made back in the 70's, kick butt.

Here's one of my favorites:

http://www.ixys.com/97538.pdf

Last I checked, Surplus Sales of Nebraska was selling these
power mosfets at about $7. USD per pop. They're a bit over-built for
what you're doing, rated 600V @ 60A.