Member
Joined 2002
Russ White said:
That's my idea but i was thinking about laying the boards flat wit the fet's flat with a nice piece of copper bar to help dissipate the heat 😛
PICS!!
So, Russ sent me a couple circuit boards:
I test fit all the components from the kit, and everything fits perfectly.
I had some time last night to build up a power supply board with kit parts (everything you see is in the kit). Here are the pics...
I am still matching FETs and building up the kits, so I hope to start shipping next week some time. I have been sick for a few days, that that's been a small delay. Anyway, we will definitelt meet or beat the Jan30 ship date.
Also, the Dales shoudl be in in the next few days, so I'll be posting something on the site for those who are interested in that upgrade.
I am also thinking of buying either Amveco or Avel tiny torroids (18x2, dual primaries) to sell to power these. More on that in the next few days.
So, Russ sent me a couple circuit boards:
An externally hosted image should be here but it was not working when we last tested it.
I test fit all the components from the kit, and everything fits perfectly.
I had some time last night to build up a power supply board with kit parts (everything you see is in the kit). Here are the pics...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I am still matching FETs and building up the kits, so I hope to start shipping next week some time. I have been sick for a few days, that that's been a small delay. Anyway, we will definitelt meet or beat the Jan30 ship date.
Also, the Dales shoudl be in in the next few days, so I'll be posting something on the site for those who are interested in that upgrade.
I am also thinking of buying either Amveco or Avel tiny torroids (18x2, dual primaries) to sell to power these. More on that in the next few days.
Ed Lafontaine said:
We were actually thinking those foam beer jackets, or maybe squishy stress balls in the shape of a twisted pear. 🙂
😱 I guess he did😀 Thats a lot🙂 Nice pics.
That is great news😉 I'll keep an eye on that site😉
Steen🙂
Re: PICS!!
Please pardon the noob question but I would need two of these? One for about 25 volts and the other for about 50. Or am I totaly wrong?
Thanks,
Please pardon the noob question but I would need two of these? One for about 25 volts and the other for about 50. Or am I totaly wrong?
Thanks,
Our current idea is that we are going to do a pair of trafos each with 2x18V secondaries. They would be used together with three of the 18V secondaries being used in series for the positive rail and one for the negative. The trafos can be stacked. 🙂 Better price then getting one custom 4 x 18V secondary trafo.
Member
Joined 2002
Can some one post dimensions of the psu board and pre-amp board ? in inches ? Im working on my chassis 😀 and i bet others are too ! 😛
My perfboard circuits just look so dumpy and sloppy now! Those pictures look very, very good. Makes me proud to have been part of it😀
Haha your perfboard circuits look better than any perfboard circuits I have ever built. 🙂
Thanks so much Terry for all your help.
And Steen thank you too for your support and your protyping! 😀
One techncal question for you. Given zener values of 75V and 25V what is the maximum secondary voltage one would reasonably use?
I was thinking 56V(2x28) but those are harder to find then 60V(2x30). And 18V for the negative rail(2x9).
Thanks so much Terry for all your help.
And Steen thank you too for your support and your protyping! 😀
One techncal question for you. Given zener values of 75V and 25V what is the maximum secondary voltage one would reasonably use?
I was thinking 56V(2x28) but those are harder to find then 60V(2x30). And 18V for the negative rail(2x9).
There is no technical limit for the secondaries, just practical limits. The limit is governed by the power dissipation that the regulating transistors must deal with. For a 60V secondary, if using one powersupply to supply both channels, the +ve regulator FET will be dissipating about 2.5W, so given the heatsinks you are using, it shouldn't be a problem.
60V(AC) x sqrt(2) ~= 85V(DC) pre-regulator
85V-70V = 15V drop across +ve regulator FET
0.08A bias x 2 channels = 0.160A current through +ve regulator FET
15V x 0.16A = 2.4W dissipation.
Calculation is much the same for the -ve FET.
Does this answer your question?
One quick observation, an 18V for the negative secondary only gives ~25VDC, which is a little on the shy side. I'd try to find something between 20V and 24V for the negative secondary, with a minimum limit of 18.5V.
60V(AC) x sqrt(2) ~= 85V(DC) pre-regulator
85V-70V = 15V drop across +ve regulator FET
0.08A bias x 2 channels = 0.160A current through +ve regulator FET
15V x 0.16A = 2.4W dissipation.
Calculation is much the same for the -ve FET.
Does this answer your question?
One quick observation, an 18V for the negative secondary only gives ~25VDC, which is a little on the shy side. I'd try to find something between 20V and 24V for the negative secondary, with a minimum limit of 18.5V.
Okay, built up a pre board, but no FETs on it yet, as I have not finished the matching, but you can get the idea.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
ha ha
Seriously Brian those output caps are very cool! Huge! 🙂 But I am glad they look like they fit great!
Cheers!
Russ
Cheers!
Russ