cbutterworth said:
Thanks SY You DID IT
I think we have a first here!!!!! see 2nd line post#1
The B+ Voltage is shared per the tube by each plate.
That way the B+voltage is rated at/by the valve spec. sheets and also as rated in John B's table at the end of the USERS GUIDE provided with his PCB kit.
Thanks Sy!
I'm on my way to brouse around in "The Red Light District"
I am very happy to know I was not the only one confused by the Aikido B+ values.
Ron
Yes, but I lost EC8010, who is an actual engineer. So forget everything I said, it must be wrong.
EC, if I haven't already, I hereby officially recommend Shive and Weber's "Similarities in Physics." I've thoroughly annoyed my co-workers by modeling diffusion of gases through a barrier with electrical analogies...
Good luck with that; EC and I did that for real last year in Amsterdam, and I'm afraid I damaged him a bit.
EC, if I haven't already, I hereby officially recommend Shive and Weber's "Similarities in Physics." I've thoroughly annoyed my co-workers by modeling diffusion of gases through a barrier with electrical analogies...
Good luck with that; EC and I did that for real last year in Amsterdam, and I'm afraid I damaged him a bit.
Trust me, he has a much better story about me.
We were out at an excellent beer bar (Gollem) and started to walk (stagger, really) back to our hotel. A local guy, Erik deBest, was with us. We weren't exactly in the Red Light District, but sort of skirting around the edges. As happens there, a furtive guy with a small brown paper bag comes up to us, goes directly to ME out of the three of us, proffers the bag and asks, "Viagra?"
We were out at an excellent beer bar (Gollem) and started to walk (stagger, really) back to our hotel. A local guy, Erik deBest, was with us. We weren't exactly in the Red Light District, but sort of skirting around the edges. As happens there, a furtive guy with a small brown paper bag comes up to us, goes directly to ME out of the three of us, proffers the bag and asks, "Viagra?"
Sy,
No Doubt it was because YOU were the most sober of the three.
Cbutterworth,
Using the formula for calculating the min. size of the choke needed, I was lucky enough to end up at 6.045. I have read also that using the Fairchild Stealth FREDs will assist in prevention of ringing. Perhaps I should buy a 10H just to be safe.
Without spending $$$ on a choke, any recommendations for suppliers?
Is there a formula for determining the inductance value (choke size) of a transformer using a DMM?
This is a wonderful learning thread !!! THANKS ALL
Ron
No Doubt it was because YOU were the most sober of the three.
Cbutterworth,
Using the formula for calculating the min. size of the choke needed, I was lucky enough to end up at 6.045. I have read also that using the Fairchild Stealth FREDs will assist in prevention of ringing. Perhaps I should buy a 10H just to be safe.
Without spending $$$ on a choke, any recommendations for suppliers?
Is there a formula for determining the inductance value (choke size) of a transformer using a DMM?
This is a wonderful learning thread !!! THANKS ALL
Ron
I am using the Hammond 193G, it is 10H. I cannot remember the price, but somewhere around the $30 sounds right. Try looking at the AES website www.tubesandmore.com
They keep many of the Hammonds in stock, although other suppliers such as Digikey can order them for you.
As for the FRED, I have no idea if it'll work, but as you already have the 6H choke, why not give it a try, if this choke rings, then maybe invest in a 10H.
Keep the forum informed, as we can all benefit from the input.
Charlie
They keep many of the Hammonds in stock, although other suppliers such as Digikey can order them for you.
As for the FRED, I have no idea if it'll work, but as you already have the 6H choke, why not give it a try, if this choke rings, then maybe invest in a 10H.
Keep the forum informed, as we can all benefit from the input.
Charlie
If a choke is "ringing" you likely won't hear it. You'll have a B+ that is not quite stable. It will have some overshoot. Model it in PSUD2 with a slight change (+1mA) in current draw. For a portion of a second after the change, you'll see the B+ swing past the target voltage, then reverse and swing back up, again missing the target. Typical underdamped filter response.
I've had some issues with it in my CLCLC filter. I had two 15H chokes as each L....without HUGE amounts of capacitance, that shows severe ringing.
In my case, the ringing showed up as subsonic woofer pumping.
I've had some issues with it in my CLCLC filter. I had two 15H chokes as each L....without HUGE amounts of capacitance, that shows severe ringing.
In my case, the ringing showed up as subsonic woofer pumping.
Ringing and Swinging
Jayme,
Wow! That's interesting.....I never would have suspected "Ringing" to manifest itself in that way. Do you suspect it was due to the Cap sizing in the filter or the desgn?
I do recall reading (but not where), that the first C should be no larger than 8 Ohms, and the last should not be "Huge". Whatever Huge is.
Anybody else have different results from "Ringing"?
Ron
Jayme,
Wow! That's interesting.....I never would have suspected "Ringing" to manifest itself in that way. Do you suspect it was due to the Cap sizing in the filter or the desgn?
I do recall reading (but not where), that the first C should be no larger than 8 Ohms, and the last should not be "Huge". Whatever Huge is.
Anybody else have different results from "Ringing"?
Ron
No, it's exactly that- as the power supply bounces around, so does the desired signal. Bad juju. Sizing of components depends strongly on the design of the supply- I tend to use C input and no long strings of inductors (which is just asking for instability). For CLC filters, the first C should be moderately sized to keep ripple currents low, the second can be as big as you like.
What you want to do is ring the bell, and to do that, you have to tap it with a small hammer. Use the stepped current option and pick a current that's (say) 15% higher than nominal. Step to it after (say) 10 seconds, then look at the output between 9 and 12 seconds. That's where the ringing will show up. A good supply will show a monotonic exponential decay from the initial to the final value.
How do you use the stepped current option? Is this in a later upgrade or different download? I'm intrigued by this program now because of the absolute faith many people are putting in a (much) simplified simulation. It's right up there with using the most basic form of the three-halves law to predict tube amplifier performance.
John
Kick *** SY,
I tried that and it worked like a charm! I never would have known what to look for concerning ringing. I had slight ringing that was a repeating pattern, So I am plugging in new #s for the Caps & Resistors.
Just from playing with PSUII I have learned how different size components effect the PS. It's FUN to learn!
Thanks for the help SY.
Ron
I tried that and it worked like a charm! I never would have known what to look for concerning ringing. I had slight ringing that was a repeating pattern, So I am plugging in new #s for the Caps & Resistors.
Just from playing with PSUII I have learned how different size components effect the PS. It's FUN to learn!
Thanks for the help SY.
Ron
With all the help I've been given on this project and the GREAT program PSDII, I think I have come up with an extremely smooth DC supply for the B+ rail on my Pre-amp. If you see anything glaring please post your concerns.
OT
My son is a Mechanical engineer and programs PICs on a regular basis, we are going to build a Digital remote controlled volume and input switch using a Parralax Propeller chip for the 9 pin Aikido Preamp. As we proceed I will start a new thread to display our progress.
Thank you,
Ron
OT
My son is a Mechanical engineer and programs PICs on a regular basis, we are going to build a Digital remote controlled volume and input switch using a Parralax Propeller chip for the 9 pin Aikido Preamp. As we proceed I will start a new thread to display our progress.
Thank you,
Ron
Attachments
You mentioned Morgan Jones earlier in the thread, right? If you check out pages 315 to 318 (in the Third Edition) you will see traditional and improved methods of choke snubbing to prevent ringing, along with a clear and detailed explanation of how and why ringing occurs and what effects may be expected from both methods of snubbing. While this may not allow the use of a choke that is way out of spec, it seems to be a very useful exercise for any CLC filter stage, requiring minimal components to implement.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.