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Recommendations for essential measurement tools for HV hobby...

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mzincali

Fri Oct 07 2011, 11:46PM

Registered Member #4127 Joined: Fri Oct 07 2011, 05:40PM
Location:
Posts: 22

Hi everyone! It looks like I have found a new hobby - like I needed yet another one.

I'm making plasma sculptures, and am also really interested in making big arcs and tesla coils.

I think there is a set of measurement tools that will make my life easier, and I am hoping you can add to the list and also tell me what brands are the most cost-effective - remember, this is just a hobby (in a down economy):

1. Good multimeter

- resistance
- continuity
- volts and current, DC & AC
nice to have:
- capacitance
- inductance
- transistor

2. HV probe for said multimeter

- measures up to 40kV

3. A frequency counter (?) up to 1MHz (?)
4. An oscilloscope (or digital acquisition device to show waveforms on a computer), the more inputs the better, up to 1Mhz(?)
5 (not a measurement tool) A good power supply to generate up to 16V and 50V at the same time or two power supplies

What else would be nice to have, and would speed up development? And reduce the number of transistors and MOSFETs I burn up?

I would love links to online suppliers and eBay auctions to get an idea of what brands and price ranges to consider.

Thank you all in advance.

genious 7

Sat Oct 08 2011, 01:49AM

Registered Member #2887 Joined: Sat May 29 2010, 11:10PM
Location: Panama City, Panama
Posts: 107

Well, that is going to be an expensive list if you buy it. all. The following suggestions are based on the monetary point of view, not the optimum conditions.

I know its not optimum, but I've been working fine without most of that. You will definitely need a multimeter. The measuring probe may or may not be required.

Do you think you need to know the exact voltage you have, or can you do with rounding based on spark length? Use this answer to consider buying one. I've done fine up to now, although I've done only basics (flybacks, arcs, and a small SSTC). Any multimeter with an inductace function is going to be expensive, I do not recommend it until you are sure you are staying in this hobby.

Frequency counter: meh, I've done without one. If you get an oscilloscope, scratch this one from the list. If not, I'd still think about it, based on budget.

Oscilloscope: This is an expensive one, but it grants the best view of what is happening. I've been doing fine without one, but sometimes when troubleshooting I hoped I had one. If you buy one, get a 10x or 100x probe for it. Still, good but not necessary if copying designs, extremely useful if making or designing your owns.

Power Supply: Yes, you will need one. If on a tight budget, you might reuse a computer ATX power supply for +12 and +5 volts. More than the 50v supply, you need a Variac. It makes testing safer (for Mosfets, not for you; they are usually not isolating). You can do without a Variac, but expect to burn more MOSFETS and more spectacular failures.

Needed additions: soldering iron (temperature control is nice, but not critical or necessary. Get a decent one and a good solder. No radio shack irons, some of them are bad quality. Weller is a good brand to start, change to Hakko if you really like the hobby later on)

Well, this is just from the economy perspective. Maybe someone more experienced will be able to tell you an optimum combination of money to features.

Mads Barnkob

Sat Oct 08 2011, 06:26AM

Registered Member #1403 Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968

I have a Fluke and Elma multimeters, these are expensive brand meters that I only have because it was a gift. High cost brands only give you a better guarantee of the promised safety. I would just use two cheap multimeters if I had not had these. Two is important so you can measure Volt / Ampere at the same time, or compare two voltages or currents.

Get a cheap LCR meter from ebay, works like a charm and measures on par with my Fluke meter,

You can modify ATX power supplies to work as a lab power supply, cheap and good for starter, some day you get lucky and run upon a large cheap supply. A variac is also a good sturdy variable powersupply, put it through a isolation transformer with rectifier bridge and electrolytics and it will serve you forever.

Soldering iron, I bought the cheapest used Weller station I could find in Denmark, have served me perfectly over the years and only one tip change :)

I was lucky to find a 0 - 57 Volt 25A supply for almost nothing, keep your eyes open at HAM fests.

I have a old standalone 40kV TV repair probe, never used it... I think I will mod it to work with my oscilloscope. Spark length is a good enough indicator on your voltages, for hobby use.

I use my scope as frequency counter, I have a old 20MHz analog scope, bought very cheap at a local HAM fest and a Rigol DS1052E (

) bought from hong-kong, packs a whole lot of features to a good price when comparing to other DSOs.

Dr. Slack

Sat Oct 08 2011, 06:50AM

Registered Member #72 Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659

If you have decent multimeters, you also need some really cheap ones, to do the first measurements with. It really hurts to hear that 'zzzzzzzt' from your expensive Fluke because you goofed and unleashed 2kV into the 1kV range (that's all it takes, I've done it).

I now have a lot of cheap ones.

Pinky's Brain

Sat Oct 08 2011, 09:31AM

Registered Member #2901 Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837

Why don't these expensive multimeters just have a replaceable crowbar switch (two TVS diodes in anti-series) on the input? With HF measurement the extra capacitance is killer, but with a multimeter the extra protection seems much more convenient.

Antonio

Sat Oct 08 2011, 01:13PM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

Absolutely essential:
Soldering irons, one big and another small, and desoldering tool.
Multimeter. The cheap ones are good enough for most work. It's good to have one digital and another analog.
Power supply. Learn to make one and have several. If you want just one, a dual adjustable +/-15 V, 1 A is enough.
Solderless breadboard, for experiments at -low power-.

For any serious work:
Oscilloscope, 50 MHz dual channel at least.

Useful:
Capacitance and inductance meter.
Signal generator (easy to make one).

Useless:
Frequency counter. If you have an oscilloscope you don't need one, and if you don't have it is useless.
HV probe. Best to avoid instruments connected to high voltage, or to learn how to make measurements in a safer way. Otherwise you -will- destroy instruments.

sparky99

Fri Dec 30 2011, 05:56AM

Registered Member #1159 Joined: Fri Dec 07 2007, 02:10AM
Location: Hudson Valley of NY State
Posts: 84

One of these would be nice:-D

Sparky 99

1325224547 1159 FT125836 1278895520 1159 Ft0 J1003 003

1325224548 1159 FT125836 1278895476 1159 Ft0 J1003 002

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