Cheap loadtester materials

[jinu117]

*** Updated... post 32 has instruction & picturres ***


Since lot of people have no way of load testing and safe way of doing it here is guide to components involved in making loadtester that is rather cheap. I found some components which are readily available online in US as well as easy to work with for it. I will update this with some pics as I get some time and full guide on how to make it with picture.

1) You need heating element. Lot of people go for power resistor. It is all good but what happens when you get condensation on it. Also, how well can you mount multiple of them correctly? Answer is.... not really as I've seen way too varying load figures from people.
Here is what I recommend. Cartridge heater.
McMaster.com carries one. Hightemp 1/4 diameter, 1-1/2" length is good choice. 3618K182 from mcmaster.com. It is about $20. You can get high temp sleeving on it, etc. (I suggest grabbing 200w one with stainless steel cable)
2) Copper block. About 2x2x1/2" is good choice. What you do is basiaclly drill this with same diamter as your cartridge diameter drill small hole for thermcouple in between surface and this hole for getting good idea on contact when you test. (no load same temp 150w load up to about 11c is good contact) DangerDen sells them for $5 a piece if you can't find one locally.
http://www.dangerdenstore.com/home.php?cat=49
3) AC cable to connect to cartridge. I am pretty sure most of you have them laying around.
4) Load varying station (Variac). I used to use variac from all electronics that was about $50. While it is very good, I found cheaper source for doing same thing. Basically rotary speed controller for your ac sources. You can use it just fine and it does work just same as variac. **UPDATE** stuff I got from harborfreight.com works just fine. http://da.harborfreight.com/cpisearc...3060&Submit=Go On sale around $10.
5) Way to know exact wattage used. I use kill-a-watt reader. Many places will have it from $20-35. E-bay is not a bad choice on this one if you can find reasonable shipping fee one which is always available from what i can see.
Total spent is less than $100 for very accurate load testing setup. I will write more about how to make one for those who just didn't get it later.

[runmc]

Thank you jinu for the nice guide.
I have ordered my heating element. I already have the copper and speed controller. All I need is the "kill O what" reader
Can you explain more about this tool? Where do you find one? HD?

[wdrzal]

volts X amps =watts

a volt meter with a amp clamp =watt meter

[runmc]

volts X amps =watts

a volt meter with a amp clamp = watt meter

Do you mean like - 120v X 2amps = 240watts ??

Where do you clamp the "amp clamp"?

[n00b 0f l337]

Runmc, will you be able to maybe assemble and few and offer them from under-the-ice for people?

[kayl]

Do you mean like - 120v X 2amps = 240watts ??

Where do you clamp the "amp clamp"?

can get fluke clamp or something
The clamp goes around the active wire and measure the magnetic field around the wire and turns that into a current reading.

I just modded an entension lead and plug it into a volt meter to measure current



nice guide there jinu117, now we just need some pics

[wdrzal]

Do you mean like - 120v X 2amps = 240watts ??

Where do you clamp the "amp clamp"?

yep, just remember if using a clamp you only go around 1 wire or they flow will cancel each other out.

some meters without amp clamps you can direct read amps by running the load thru the meter.

[epion2985]

Very nice, thanks jin. You helped me save some money as some of the components I was about to get were more. Thanks

I do not see the need for a kill-a-watt reader. I mean kmon guys, amps * volts = watts, you all should know that much.

[n00b 0f l337]

The point is, you dont know what amperage its sucking without it.
So your left with 110a=w. And that doesnt help much.

[epion2985]

most volt meters can give amp measurements.

I think the Variac jin uses tells you the amps its pushing at at $50 its a steal.
http://www.allelectronics.com/cgi-bi...NSFORMER_.html

[wdrzal]

a modern 3 to 5 dollar dimmer will also work.just check its amp rating 2 0r 3 amps at 110 to 120 volt will get you over 200 watts, they are variac's. just don't use a old time one ( resistive dimmer)as they give off the difference from input to out put in heat.

[wdrzal]

I bet you could even design a heat load by using a 150 watt light bulb. put it in a liquig filled tube and monitor the temperature. if the temp stay steady you are cooling 150 watts, if it drops your are cooling more ,if it rises less. knowing the volume of water and temperature rise x time you can calculate excact wattage. probably make something for under 10.00

[ZeroTolerance]

I bet you could even design a heat load by using a 150 watt light bulb. if the temp stay steady you are cooling 150 watts, if it drops your are cooling more ,if it rises less.

the main porpuse of a lamp = light production. The heating is just an inefficient side-effect. If the lamp eats 150W it doesn't produce 150W of heat.

[Thrilla]

I just used a 150watt firerod heating element, plug it in the AC 120v, it sucks up 150w and gets real hot in just a few seconds. Too bad I ran it without cooling... it got burnt..

[wdrzal]

yes it does produce 150 watts of heat, the light is just a bonus.

by the way a resistive heating element is very near 100% effecient

[jinu117]

I bet you could even design a heat load by using a 150 watt light bulb. put it in a liquig filled tube and monitor the temperature. if the temp stay steady you are cooling 150 watts, if it drops your are cooling more ,if it rises less. knowing the volume of water and temperature rise x time you can calculate excact wattage. probably make something for under 10.00

This is so unlike you considering safety hazard it will pose. I do understand it is just getting point through post but still... some people might read it literally
expect some pics in few days as I am quite swamped at moment from my primary work, family obligation, and phase change as well :P Been on 4 hour sleep run for last 2 weeks.

[Carlz0r]

I bet you could even design a heat load by using a 150 watt light bulb. put it in a liquig filled tube and monitor the temperature. if the temp stay steady you are cooling 150 watts, if it drops your are cooling more ,if it rises less. knowing the volume of water and temperature rise x time you can calculate excact wattage. probably make something for under 10.00

Lightbulb + cold liquid = BAD combo. 120v + Liquid = BAD combo. I agree with jinu, this is very unlike you.

[Blaster]

Spent less than 10€ on this..

lap both copper block and resistor, opened threaded holes on copper to really press resistor against copper with screws, very thin layer of thermal paste between them

it puts out same power as my opteron 170 at 3200Mhz, 1,7 vcore running both cores at 100%

[wdrzal]

A safe one could be made,or I wouldn't have mentioned it. why would the liquid have to be cold?

[Carlz0r]

A safe one could be made,or I wouldn't have mentioned it. why would the liquid have to be cold?

It would be used for loadtesting. Therefore, it would be cold.

[epion2985]

It would be used for loadtesting. Therefore, it would be cold.

No it wouldnt.

All you would do is measure the delta T, it doesnt matter in what range.

[Thrilla]

Just insulate the sucker with foam and stuff, but from what I was taught, all wall outlet project needs to be properly enclosed, and for these kinda stuff, load it with a GFI socket, might save your life someday.

[wdrzal]

That was just a off the wall thought ,but if we could design a heat load out of very cheap and common parts every could make one.

If a bulb is in a fluid when turned on it won't burst, it will work like a heating element.
come to think of it there is a company in pittsburg,Chromalox, who make all kinds of resistance heaters. I could check on what they have.

[epion2985]

I could check on what they have.

thanks. awaiting anxiously.

[wdrzal]

Here is their web site:

http://www.chromaloxheaters.com/

http://www.chromalox.com/

http://www.chromalox.com/technical/ohmscalculator/