The counter is a Veeder Root brand which has a preset switch to connect to an electro magnetic contactor for the electric motor. The drawback of this old model is that you only can unwind up to the nearest decade without loosing the count. Bought this unit about 20 years ago. Guess newer models could be more flexible on this regard.
You could connect the counter with pulleys between both pillow blocks to get it out of the business end and not having to connect and disconnect the hose coupling.
On my setup the counter and the base are actually just sitting there, not fixed, so it can be removed easily form the work area.
I bought this unit from an industrial control distributor here in Mexico.
You could connect the counter with pulleys between both pillow blocks to get it out of the business end and not having to connect and disconnect the hose coupling.
On my setup the counter and the base are actually just sitting there, not fixed, so it can be removed easily form the work area.
I bought this unit from an industrial control distributor here in Mexico.
Found a similar Veeder Root unit on the surplus market, quite expensive though, when I bought mine it wasn’t cheap either. In the other hand its excellent quality.
http://www.plccenter.com/ProductDetail.aspx?PartNum=1239356891&Manufacturer=VEEDER+ROOT
http://www.plccenter.com/partlist.aspx?VTI-GROUP=0&R1=2&T1=VEEDER ROOT
http://www.allproducts.com.tw/sup007/greatwall/zj405.html
http://www.plccenter.com/ProductDetail.aspx?PartNum=1239356891&Manufacturer=VEEDER+ROOT
http://www.plccenter.com/partlist.aspx?VTI-GROUP=0&R1=2&T1=VEEDER ROOT
http://www.allproducts.com.tw/sup007/greatwall/zj405.html
Inductance question...
Hi everyone,
I've been experimenting. The ZV7-T is now driving my JBL 2446 loaded tractrix horn (1st order, 300hz x-over point--I don't drive it hard). I'm using my QSC DSP-30 as a temporary electronic crossover.
As experiments go, I've learned that the distortion on the ZV7-T is lowered substantially when it's no longer required to operate in the bass region. Smooth as silk and twice as transparent.
I learned something else that's pretty cool. You can time delay the woofers with a 4th order x-over and allow a two foot horn with a 1st order x-over time to play catch up. It may not be pc, but it's all in good fun.
So, here's my question: what size (in mH) inductor do I need if the amp isn't operated full bore below 300hz? There's the 1st order x-over roll off rate to consider--I figure the amp is not producing much below 75hz what with the electronic x-over being 12db down at that point. If someone knows of an online calculator that can deduce mH at a prescribed frequency?
I'm all ears...
John Inlow
There's this page, but I don't know how much reactance I need.
http://home.new.rr.com/trumpetb/audio/chokejs.html
Hi everyone,
I've been experimenting. The ZV7-T is now driving my JBL 2446 loaded tractrix horn (1st order, 300hz x-over point--I don't drive it hard). I'm using my QSC DSP-30 as a temporary electronic crossover.
As experiments go, I've learned that the distortion on the ZV7-T is lowered substantially when it's no longer required to operate in the bass region. Smooth as silk and twice as transparent.
I learned something else that's pretty cool. You can time delay the woofers with a 4th order x-over and allow a two foot horn with a 1st order x-over time to play catch up. It may not be pc, but it's all in good fun.
So, here's my question: what size (in mH) inductor do I need if the amp isn't operated full bore below 300hz? There's the 1st order x-over roll off rate to consider--I figure the amp is not producing much below 75hz what with the electronic x-over being 12db down at that point. If someone knows of an online calculator that can deduce mH at a prescribed frequency?
I'm all ears...
John Inlow
There's this page, but I don't know how much reactance I need.
http://home.new.rr.com/trumpetb/audio/chokejs.html
less is better?
Thanks for your imput, flg.
I'm using only enough choke to get the amp into the 100hz low frequency cutoff range. If I cut the amp off at 100hz, I can use a smaller inductor; this equates to less copper, thus less resistance and fewer back-aches.
John
edit: I just read that reactance is similar to resistance. I knew this, but it didn't dawn on me until now that Nelson's topology normally employes power resistors. To me this means that I can substitute an inductor for a power resistor if it's reactance measures the same degree of resistance. This means that I can calculate for any cutoff frequency in the amplifier as long as the reactance (resistance) is maintained. I hope I wrote this properly. All comments welcome.
Thanks for your imput, flg.
I'm using only enough choke to get the amp into the 100hz low frequency cutoff range. If I cut the amp off at 100hz, I can use a smaller inductor; this equates to less copper, thus less resistance and fewer back-aches.
John
edit: I just read that reactance is similar to resistance. I knew this, but it didn't dawn on me until now that Nelson's topology normally employes power resistors. To me this means that I can substitute an inductor for a power resistor if it's reactance measures the same degree of resistance. This means that I can calculate for any cutoff frequency in the amplifier as long as the reactance (resistance) is maintained. I hope I wrote this properly. All comments welcome.
more thoughts...
With a large iron-core inductor, this amp can put out substantial bass. It's truly amazing. But, when playing hard down low, there's audible distortion in the upper register. So, my thought is to use the iron cored inductor for the bottom end, where my ears hear little distortion, and run the air-core inductors on the top end with the amp configured for a 75hz cutoff. Believe it or not, raising the cutoff from 20hz to 75hz changes the size of the inductor by a large margin. Instead of requiring 80mH, I only need 17mH. That's 10.5 lbs of copper vs. 23lb.
John
With a large iron-core inductor, this amp can put out substantial bass. It's truly amazing. But, when playing hard down low, there's audible distortion in the upper register. So, my thought is to use the iron cored inductor for the bottom end, where my ears hear little distortion, and run the air-core inductors on the top end with the amp configured for a 75hz cutoff. Believe it or not, raising the cutoff from 20hz to 75hz changes the size of the inductor by a large margin. Instead of requiring 80mH, I only need 17mH. That's 10.5 lbs of copper vs. 23lb.
John
John, I would guess with the whole signal, including the bass, you could be saturating the inductor. The low freq.s have much more power/current than the upper freqs. Actually I would bet an air core would be better for the lows and Iron for the top end but, I don't think it could be practicle size/weight/inductance value wise. Do you have a scope I would bet you could see saturations spikes going off the top and bottom of the screen while hearing distortion.
You can also, run a square wave of some power through the choke. You will get a ramp looking wave of current. You can use the voltage across a small value series sence resistor to measure current. As you increase the square wave duratiion, and or voltage, the ramp will rise higher and higher. When you reach saturation the ramp will start to turn and go strait up. It's a little tricky but I have to do such things at work every so often to measure other peoples stuff.
BTW. I have this realatively large transformer I keep on my desk for isolation, big step ups-downs etc. It's an E, laminated core type. It has a bunch of taps even for 440 or something. I'ld guess it weighs 40-50lbs.??? This morning I put it on a cart and rolled it over to the LCR meter... the full primary, as one would expect, was the highest...770mHs Hmmmm
One other thought. Don't you think you need to roll the speaker/amp off an octive or two before the inductor starts rolling off or whatever it does?
You can also, run a square wave of some power through the choke. You will get a ramp looking wave of current. You can use the voltage across a small value series sence resistor to measure current. As you increase the square wave duratiion, and or voltage, the ramp will rise higher and higher. When you reach saturation the ramp will start to turn and go strait up. It's a little tricky but I have to do such things at work every so often to measure other peoples stuff.
BTW. I have this realatively large transformer I keep on my desk for isolation, big step ups-downs etc. It's an E, laminated core type. It has a bunch of taps even for 440 or something. I'ld guess it weighs 40-50lbs.??? This morning I put it on a cart and rolled it over to the LCR meter... the full primary, as one would expect, was the highest...770mHs Hmmmm
One other thought. Don't you think you need to roll the speaker/amp off an octive or two before the inductor starts rolling off or whatever it does?
Yep, just had to go start lookin at some of this myself... The trafo was ratted at 1500VA. I'm thinking, as Primarys go, we would probably prefer a 440 input rating??? It would be a higher inductance than a 220, than a 110???
I'm goin in today to figure out if I remember how to use the HP339 THD meter we just got into my lab. Havent used one of those in 25+ years... The Agilent site still has the manual and it says 1979 on it... I have a modified BOSOZ I want to test. I'll bring in my 50V supply with a 650VA toriod and a 250VA unit also and measure the L of those guys too.
I really like the idea of a 750-1500VA off the shelf unit rather than me doing 800 turns of wire on a toriod. I wind stuff like flyback transformers for 1-20 Watt ac-dc smps once in a while so I think I know better than to try this monster. I have a small hand winder. I've also built a couple monster chokes for arc welders before but that was ribbon copper...
I'm goin in today to figure out if I remember how to use the HP339 THD meter we just got into my lab. Havent used one of those in 25+ years... The Agilent site still has the manual and it says 1979 on it... I have a modified BOSOZ I want to test. I'll bring in my 50V supply with a 650VA toriod and a 250VA unit also and measure the L of those guys too.
I really like the idea of a 750-1500VA off the shelf unit rather than me doing 800 turns of wire on a toriod. I wind stuff like flyback transformers for 1-20 Watt ac-dc smps once in a while so I think I know better than to try this monster. I have a small hand winder. I've also built a couple monster chokes for arc welders before but that was ribbon copper...
flg, you're one lucky dog...
I wish I had access to that kind of equipment.
With a large inductor, this amplifier has something really special going for it in the bass department. You should take that big monster tranny and build one channel for kicks. I would wire the primaries for max inductance with a center tap.
Here's something I learned:
Yesterday, I biamped my center channel with a Hafler Transnova P-7000 on the bottom end. I always thought the P-7000 was a brute with huge dampening and headroom. Now, I'm fighting the impulse to sell them on ebay. The ZV7-T sounds far superior; it's not even in the same galaxy. I wish you would build one to confirm my statement. This amplifier DOES NOT behave like a 30 watter. It's sonic signature is warm and powerful. Nelson really let the cat out of bag with this design. I remember the tube guys bragging about the wonderful bass in their SETs--I always thought they were so ignorant; how could three watts be considered powerful bass? Boy was I wrong!! It's the inductor that swings the bat in the ZV7-T, and it's hit a home run as far as I'm concerned. I will mention that my bass speakers are rated at 100db 1w1m. I'm certain this helps, but the P-7000 didn't have the means to exploit this advantage. No flavor.
Best wishes,
John Inlow
I can't imagine winding 800 turns on a torid... but then again, that's about how boring it is to paper mache my 150hz tractrix horns.
I wish I had access to that kind of equipment.
With a large inductor, this amplifier has something really special going for it in the bass department. You should take that big monster tranny and build one channel for kicks. I would wire the primaries for max inductance with a center tap.
Here's something I learned:
Yesterday, I biamped my center channel with a Hafler Transnova P-7000 on the bottom end. I always thought the P-7000 was a brute with huge dampening and headroom. Now, I'm fighting the impulse to sell them on ebay. The ZV7-T sounds far superior; it's not even in the same galaxy. I wish you would build one to confirm my statement. This amplifier DOES NOT behave like a 30 watter. It's sonic signature is warm and powerful. Nelson really let the cat out of bag with this design. I remember the tube guys bragging about the wonderful bass in their SETs--I always thought they were so ignorant; how could three watts be considered powerful bass? Boy was I wrong!! It's the inductor that swings the bat in the ZV7-T, and it's hit a home run as far as I'm concerned. I will mention that my bass speakers are rated at 100db 1w1m. I'm certain this helps, but the P-7000 didn't have the means to exploit this advantage. No flavor.
Best wishes,
John Inlow
I can't imagine winding 800 turns on a torid... but then again, that's about how boring it is to paper mache my 150hz tractrix horns.
Hi all!
Why use a toroid power transformer at all? It is about the worst i could think of in this position. They can't take very much dc (read no dc) imbalance and they will saturate quickly at low freq, no wonder it is better with really big ones! Go for a gapped core that can take some dc, it can be a toroid, C or EI. A sensible size could be 200-300VA, and put two bifilar windings on it and you are ready to go. This way it is easy to get a very good balance between dc-resistance, inductance and saturation level.
BR,
Anders
Why use a toroid power transformer at all? It is about the worst i could think of in this position. They can't take very much dc (read no dc) imbalance and they will saturate quickly at low freq, no wonder it is better with really big ones! Go for a gapped core that can take some dc, it can be a toroid, C or EI. A sensible size could be 200-300VA, and put two bifilar windings on it and you are ready to go. This way it is easy to get a very good balance between dc-resistance, inductance and saturation level.
BR,
Anders
Not that easy
Hi Anders,
I've been scouring the "net" for chokes that fit the ZV7-T's requirements.
I batted a big fat zero. The only transformer that comes close is Susan Parker's Zeus-75. But, then again, it's a transformer and what I'd really like to use is a choke.
I'm preparing to handwind one at a later date. For the bass, I want an iron core in order to keep the inductor at a sane level. I'll biamp and run the hi-frequency amp with an air-core inductor.
The 1000 v/a Plitron I'm using sounds terrific in the bottom end. It sounds terrific in the top end if I don't allow it to reproduce bass. Hence, the need to biamp.
I took a peak at the transformer you suggested--guess I'll take another to refresh my memory.
This is the best sounding/performing amp I've fabricated to date. It sounds so sweet that I'm not ready to move on to the ZV8/9 series. It's easily on par with my ax and ten times easier to construct. My
worth.
John Inlow
Hi Anders,
I've been scouring the "net" for chokes that fit the ZV7-T's requirements.
I batted a big fat zero. The only transformer that comes close is Susan Parker's Zeus-75. But, then again, it's a transformer and what I'd really like to use is a choke.
I'm preparing to handwind one at a later date. For the bass, I want an iron core in order to keep the inductor at a sane level. I'll biamp and run the hi-frequency amp with an air-core inductor.
The 1000 v/a Plitron I'm using sounds terrific in the bottom end. It sounds terrific in the top end if I don't allow it to reproduce bass. Hence, the need to biamp.
I took a peak at the transformer you suggested--guess I'll take another to refresh my memory.
This is the best sounding/performing amp I've fabricated to date. It sounds so sweet that I'm not ready to move on to the ZV8/9 series. It's easily on par with my ax and ten times easier to construct. My
worth.John Inlow
Well, I did some work over the weekend other than my CCS-BZLS... Like I said, I measured this monster 1500VA Idustrial Control Transformer, I think it should be called, last week and it was whatever I said. It had effectively a 440-220-110 Set of Primararys... And, I measured an Avel 250VA 18-0-18 and it has a 220-110 primary and also my 650VA??? Scavanged from a carver 5.1 amp and it has a 220-110 set of primararys...
In all cases, it appears that you can calculate the Pri current based on the VA rating use it to figure an "R" and use the Xl (R) to claculate the L
... Now I'm sure the ones who like to, will jump in now and tell us exactly the math of such an idea... But that's what it looked like... ie: the 250VA Avel... 1Pri side is 125VA/115VAC => 105 ohms => @ 60Hz => .28H and that is what it measures
Another area of interest here is the freq responce of this thing. A big iron laminated thing, Hey! anyone can correct me, is operated @ 60Hz, O.K. 50-60Hz, What do you think happens to all that laminated mess at high freq???? I will test up to 500Hz and 5A next time I get motivated. I'm expecting only Ferrite is usefull to avoid non-linear behavior at upper freqs (>1000).
Next, I will try what was suggested, I beleive, and that was an SMPS style transformer/Inductor. At least I think I read into something like I know how to do, a few posts back. Something like the biggest bobbin/core combo I have, EE type thing. A real peice of info, Hmmm, O.K. I found a Ferrite core today, about 3" square and 1" thick... Did'nt find a bobbin to fit... I ussually gap something with 400 paper and it's 1/4" square I have to gap a 1" square now!!! I need some kinof grinding machine or somethin??? I guess I can use all shim stuff to gap it??? O.K. Next I will need to calculate a little... Basically, it's the same ol gig. The biggest/smallest wire and as many turns as fit. Then, as Neslon might say, Gap to taste
I have also tried to simulate this bis with Pspice and I am not finding what I might expect, I need to use a real CT transformer and I'm only using 2 inductors at the moment...
In all cases, it appears that you can calculate the Pri current based on the VA rating use it to figure an "R" and use the Xl (R) to claculate the L
... Now I'm sure the ones who like to, will jump in now and tell us exactly the math of such an idea... But that's what it looked like... ie: the 250VA Avel... 1Pri side is 125VA/115VAC => 105 ohms => @ 60Hz => .28H and that is what it measures Another area of interest here is the freq responce of this thing. A big iron laminated thing, Hey! anyone can correct me, is operated @ 60Hz, O.K. 50-60Hz, What do you think happens to all that laminated mess at high freq???? I will test up to 500Hz and 5A next time I get motivated. I'm expecting only Ferrite is usefull to avoid non-linear behavior at upper freqs (>1000).
Next, I will try what was suggested, I beleive, and that was an SMPS style transformer/Inductor. At least I think I read into something like I know how to do, a few posts back. Something like the biggest bobbin/core combo I have, EE type thing. A real peice of info, Hmmm, O.K. I found a Ferrite core today, about 3" square and 1" thick... Did'nt find a bobbin to fit... I ussually gap something with 400 paper and it's 1/4" square I have to gap a 1" square now!!! I need some kinof grinding machine or somethin??? I guess I can use all shim stuff to gap it??? O.K. Next I will need to calculate a little... Basically, it's the same ol gig. The biggest/smallest wire and as many turns as fit. Then, as Neslon might say, Gap to taste
I have also tried to simulate this bis with Pspice and I am not finding what I might expect, I need to use a real CT transformer and I'm only using 2 inductors at the moment...
As promised, here you got a couple of pics of a 2*80mH air core inductor.
http://www.briangt.com/gallery/magura-inductors
Magura
http://www.briangt.com/gallery/magura-inductors
Magura
sexy...
Magura, those are very professional looking chokes. I take it that the 20 kilogram unit is 80-0-80?
Is this DIY stuff or did you hire this baby out? Regardless, it's a beauty.
What became of it? Oh, and what gauge wire and it's resistance, what kind of tape, and how hot does it run?
Impressed and inspired,
John
Magura, those are very professional looking chokes. I take it that the 20 kilogram unit is 80-0-80?
Is this DIY stuff or did you hire this baby out? Regardless, it's a beauty.
What became of it? Oh, and what gauge wire and it's resistance, what kind of tape, and how hot does it run?
Impressed and inspired,
John
Re: sexy...
This is DIY 100%. It just might be a little expensive to have such made in a shop
It has been used for my ZV7 test rig, makes no noise, does not vibrate and becomes luke warm.
It's 1.9mm wire, somewhere around 2 ohm DCR.
The tape is bog standard self extinguishing cotton tape.
Magura
carpenter said:Magura, those are very professional looking chokes. I take it that the 20 kilogram unit is 80-0-80?
Is this DIY stuff or did you hire this baby out? Regardless, it's a beauty.
What became of it? Oh, and what gauge wire and it's resistance, what kind of tape, and how hot does it run?
Impressed and inspired,
John
This is DIY 100%. It just might be a little expensive to have such made in a shop
It has been used for my ZV7 test rig, makes no noise, does not vibrate and becomes luke warm.
It's 1.9mm wire, somewhere around 2 ohm DCR.
The tape is bog standard self extinguishing cotton tape.
Magura
Magura, Very nice...
If anyone is interested, my qwest for the ideal inductor hasent gone so far... The 3"x3"x1" Ferrite I thought I had was actually Powdered Iron
Another no-no I beleive but better than laminations... I have selected a smaller Ferrite EE and bobin for a test. I cant' be to accurrate but my guess is it's 3F3 material, the bobin Hole is 3/4'x5/8 and the core outer dims are about 1 3/4" sq.x 3/4" thick... Not to Big but it's a test...I have never built an SMPS with such a large Xfmr before, this could be interesting... I will try 22Ga wire first??? It is smaller than I expect to use in the finished unit but so are all the other components. I think some of you might find this interesting but normally I have customer dictated parameters for an SMPS and the core size will be deduced from these requirements. We have spreadsheets and experts to ask and stuff. But we do power supplies... In this project the biggest easiest looks good. I don't have any really big stuff at hand anyway...After some tests I may be able to get samples of something that is made for the application and designed appropriately... I almost always wind at least 1 of my own transformers before I ask for samples from a manufacturer.
The Bi-Filar part will be fun... I normally only have 5-10 Bi-Filar turns... I have to do a few hundred! if I can... Rule 3) (after Biggest & Eaiest) Whatever fits... And then, Its Gap to Taste... I don't remember the exact relatiomnship but there will be Current Saturation and L limits to this gapping bis... We will see... Maybe tonight...
If anyone is interested, my qwest for the ideal inductor hasent gone so far... The 3"x3"x1" Ferrite I thought I had was actually Powdered Iron
Another no-no I beleive but better than laminations... I have selected a smaller Ferrite EE and bobin for a test. I cant' be to accurrate but my guess is it's 3F3 material, the bobin Hole is 3/4'x5/8 and the core outer dims are about 1 3/4" sq.x 3/4" thick... Not to Big but it's a test...I have never built an SMPS with such a large Xfmr before, this could be interesting... I will try 22Ga wire first??? It is smaller than I expect to use in the finished unit but so are all the other components. I think some of you might find this interesting but normally I have customer dictated parameters for an SMPS and the core size will be deduced from these requirements. We have spreadsheets and experts to ask and stuff. But we do power supplies... In this project the biggest easiest looks good. I don't have any really big stuff at hand anyway...After some tests I may be able to get samples of something that is made for the application and designed appropriately... I almost always wind at least 1 of my own transformers before I ask for samples from a manufacturer.The Bi-Filar part will be fun... I normally only have 5-10 Bi-Filar turns... I have to do a few hundred! if I can... Rule 3) (after Biggest & Eaiest) Whatever fits... And then, Its Gap to Taste... I don't remember the exact relatiomnship but there will be Current Saturation and L limits to this gapping bis... We will see... Maybe tonight...
hi flg...
I'm intrigued--but concerned... shouldn't your wire gauge be at least 18. Seems like 22 gauge will create a lot of resistance, thus heat. That is, unless your bias is much lower than 2x3 amps.
I'm very curious about the core. Where can I find more info regarding non-laminated cores?
Thanks,
John
I'm intrigued--but concerned... shouldn't your wire gauge be at least 18. Seems like 22 gauge will create a lot of resistance, thus heat. That is, unless your bias is much lower than 2x3 amps.
I'm very curious about the core. Where can I find more info regarding non-laminated cores?
Thanks,
John
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