Resistor Bank Build Log COMPLETE 2/12/14 12pm

[Chris Hammer]

It was CJ. The problem he showed was that on a nice oscope the ad1 will still pick up distortion first..slight..but it does. The video has to be looked at frame by frame almost though...IMO I didn't see anything wrong with oscope method if you keep a good eye on it. Keep doing what your doing its badass. I hope one day to have the equipment necessary to build a bank and test too. Very cool man love the fosgate heat sink

[Jessica]

It was CJ. The problem he showed was that on a nice oscope the ad1 will still pick up distortion first..slight..but it does. The video has to be looked at frame by frame almost though...IMO I didn't see anything wrong with oscope method if you keep a good eye on it. Keep doing what your doing its badass. I hope one day to have the equipment necessary to build a bank and test too. Very cool man love the fosgate heat sink

I agree, very awesome project. I just wanted to help out because someone else showed that even with a fixed load clamping can be difficult to do. The more information the better.

I honestly wasnt trying to come in here a say this wouldnt work or start a fight.

[alaskanzx5]

he did a vid of the ad-1, amm-1, and clamping (clamping as in the incorrect way that is easily found on youtube/google)

true enough he did use the incorrect method of clamping but it is what clamping has become over years of people trying to find a quick easy way of doing it. the vid was only to show the ease and accuracy of the amm-1 though and not disband clamping all together since there is a correct way of doing it.

[S15_Silvia]

This is pretty cool. Handmade devices like this are among my favorite things to watch the builds of.

[P4killer_]

Its simple well kinda. With a load such as a speaker, we measure the current and voltage to get power. Multiply the 2 together.

Volts x amps = watts. Except thats wrong. Its actaully vars.

This is because the voltage and current arent in phase. Which usually results in high measurement. Its off by ohh about 15% but could be more or less depending.

So if you clamp your amp using a speaker as the load, V x I = W will give you a higher number than it really is. The amount the current and voltage are out of phase is called the power factor.

You need to know this to get a true reading when using a speaker as the load.

So V x I x PF will equal power. Measured in watts.

So say you clamp 10volts and 10amps. Thats 100 watts right .. no

You find out ur pf is .8

So really ur actual power is

10volts x 10amps x .8 = 80watts true power.

So he I using a resistor BECAUSE the current through a resistor and the voltage across the resistor ARE IN PHASE.

Which means the result WILL be 100% accurate. Its just the nature of the resistor. No need for power factor.. no need for expensive tools to find the pf. V x I does equal true power.

The thing is resistor s can only handle so much power before they melt lol which is why he listed the ratings. If you wanna clamp bigger amps youre gonna need some big ass resistors.

I believe the ad1 works the same way. Iirc its bullet train brakes that create a resistive load to the amp. Of course the thing can with stand some serious power. .

But using resistors like he is.. you can get the same results BASICALLY.

The above is all very loose of course, but basically right iirc.

[michigancapri92]

totally been thinking about doing this for all my led tail lights all 8 of them.

[Jessica]

p4, what happened in the ad-1 video is that the dyno runs to clipping, but doesnt measure when it detects clipping. The meters just kept reading because they just read what is given to them

So the meters read higher number because the dyno had stopped calculating already.

So, if Rolex has a way to guarantee that the amp isnt clipping, then his resistor bank will work fine.

But, i think the only way he can do that is to either set gains with the dd-1 and do it slightly conservatively, or get a very high resolution o-scope and record his test and go back frame by frame in the video and watch for the clipping and do the math on those numbers just before clipping occurs.

Keep in mind the dd-1 has 3db of overlap built in even with the 0db tone being used iirc.

I didn't want to post all this because im sure rolex already has all this planned out or maybe an even better way.

[P4killer_]

Clipping power is stillllll more power. Its just dirty. Which isnt good I agree.. but a lil clipping will give you a lil more power equals more spl. Ppl do it all the time in competitions.

But generally clipping is bad yes. I was just saying all that pf stuff for the people wondering wtf the resistor bank is for..

[alaskanzx5]

its simple really, the bank is to put a constant load on the amps so that when he clamps while making sure he isn't clipping using an oscope with a high res he can get a more accurate reading. im wondering as to what device he is going to compare it to to show how accurate his results are compared to another device/method. the amm-1 would be good since we know it to be accurate. not as in a clamp vs amm-1 but just the amm-1 as the known accurate result and the at home clamp bench he is making as the correct method to get an accurate result.

otherwise with out something that gives us the true rms power for the amp there is nothing to compare his results to to see how accurate his home made clamp bench is.

[TaylorFade]

Sweet ass little project.

And I don't know why you guys keep saying "clamping" with this project. Fixed resistance. You don't need a current clamp.