Ok. so like for the v-reg's we have a floating ground for the caps. Then we only have to deal with the difference between rectified DC and 45V adjusted. A 35V rating should do the job and I will use some 35V/2200uF Pana Fc that I already have. For the digital rail I have some 25V/2200uf Pana AM that should do fine.
I hope I will not pick up some real ground somewhere....... it would make a lot of smoke !!!
b.t.w. does the fet's and power resistors (Caddoc's) have to be isolated (electrically) from the chassis?
Thanks,
Nic
I hope I will not pick up some real ground somewhere....... it would make a lot of smoke !!!
b.t.w. does the fet's and power resistors (Caddoc's) have to be isolated (electrically) from the chassis?
Thanks,
Nic
Hi Guys,
I've been feeling a little under the weather today, so I haven't been on, but I just caught some of the capacitor talk.
All those electrolytic caps are indeed subject to high voltage, so you do need to use the proper voltage for them.
C1, C2, C4, C5 need to be 63VDC minimum or possibly higher depending on your transformer selection and line voltage. I'm using the 40VAC Antek transformers which gives me about 51VDC before the regs, so 63VDC caps are more than enough. I'm using Nichicon 63V, 2200uF PW series because they're very good caps.
C23, C24, C26, C27 need to be rated at whatever you decide to run your rails at. I would suggest using the same 63V parts here since 50V caps would be cutting it very close. Again, I'm using the same Nichicons as above.
The output coupling caps C28, C29, C51, C52 need to be rated for at least 35VDC.
There seems to be some confusion about floating grounds with the regs, but this circuit is no different than any standard regulator circuit. The ground is not floating, it's just run in a dual mono manner to prevent hum and ground loops. All grounds are tied together at the pins of the Buffalo.
If we look at the regulator, things will maybe make a little more sense. The input pin of the reg is at 51VDC, The adjust pin is around 44VDC and the output pin is at 45VDC. There's no more than a 7V differential on the regulator because no part of it is actually connected to ground. The caps on the other hand are definitely tied to ground! Every cap in that circuit sees at least 44VDC, so it's very important to use an adequate voltage rating.
I hope nobody has blown anything up!
As for isolation on the heatsink, most of the resistors are already isolated, but the fets absolutely need to be isolated with proper pads or mica. The absolute best thing to use here would be a slightly thicker thermal pad. It would allow for some wiggle room in the height of the parts and still give good conductivity.
res07njc:
I don't see any reason you couldn't do this, as long as you can find room to jimmy it all in. They will all need to be isolated though, but this applies to the on-board sinks as well.
I think I'll probably write up a little document when I get a few minutes of some of the key points during assembly. It might help avoid confusion in the future.
Cheers,
Owen
I've been feeling a little under the weather today, so I haven't been on, but I just caught some of the capacitor talk.
All those electrolytic caps are indeed subject to high voltage, so you do need to use the proper voltage for them.
C1, C2, C4, C5 need to be 63VDC minimum or possibly higher depending on your transformer selection and line voltage. I'm using the 40VAC Antek transformers which gives me about 51VDC before the regs, so 63VDC caps are more than enough. I'm using Nichicon 63V, 2200uF PW series because they're very good caps.
C23, C24, C26, C27 need to be rated at whatever you decide to run your rails at. I would suggest using the same 63V parts here since 50V caps would be cutting it very close. Again, I'm using the same Nichicons as above.
The output coupling caps C28, C29, C51, C52 need to be rated for at least 35VDC.
There seems to be some confusion about floating grounds with the regs, but this circuit is no different than any standard regulator circuit. The ground is not floating, it's just run in a dual mono manner to prevent hum and ground loops. All grounds are tied together at the pins of the Buffalo.
If we look at the regulator, things will maybe make a little more sense. The input pin of the reg is at 51VDC, The adjust pin is around 44VDC and the output pin is at 45VDC. There's no more than a 7V differential on the regulator because no part of it is actually connected to ground. The caps on the other hand are definitely tied to ground! Every cap in that circuit sees at least 44VDC, so it's very important to use an adequate voltage rating.
I hope nobody has blown anything up!
As for isolation on the heatsink, most of the resistors are already isolated, but the fets absolutely need to be isolated with proper pads or mica. The absolute best thing to use here would be a slightly thicker thermal pad. It would allow for some wiggle room in the height of the parts and still give good conductivity.
res07njc:
I don't see any reason you couldn't do this, as long as you can find room to jimmy it all in. They will all need to be isolated though, but this applies to the on-board sinks as well.
I think I'll probably write up a little document when I get a few minutes of some of the key points during assembly. It might help avoid confusion in the future.
Cheers,
Owen
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ermm but the regulators are floating, they do not have a ground reference, how can they be anything but floating? I admit I havent even been looking at the regulator circuit, so i'll just buy out of giving any advice, because I do not plan on using it either. if they had a ground reference they would die in this circuit. I did mean to specify 1000/50 regardless though, but probably best at 63.
OMG owen, sorry man thats terrible, note to self, never give out advice other than from or to do with personal experience on a forum at 4am, I was taking this as a floating bridge circuit due to all the talk of a floating supply earlier in the thread. very sorry guys, hope everything is OK. have printed everything out including the PSU circuit now
OMG owen, sorry man thats terrible, note to self, never give out advice other than from or to do with personal experience on a forum at 4am, I was taking this as a floating bridge circuit due to all the talk of a floating supply earlier in the thread. very sorry guys, hope everything is OK. have printed everything out including the PSU circuit now
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Hi Guys,
Well, the last few boards went out last night, and I've attached the last update to the list. There is only one board left unsold, and I'm pretty sure Yoke is going to take it.
Anything that shipped on the 30th was upgraded to priority air mail to make up for the late shipping. It took me a while to get around to soldering Merlin and Pierre's boards.
I'll be starting a new build thread shortly, and people can post there about any assembly questions.
Cheers,
Owen
Well, the last few boards went out last night, and I've attached the last update to the list. There is only one board left unsold, and I'm pretty sure Yoke is going to take it.
Anything that shipped on the 30th was upgraded to priority air mail to make up for the late shipping. It took me a while to get around to soldering Merlin and Pierre's boards.
I'll be starting a new build thread shortly, and people can post there about any assembly questions.
Cheers,
Owen
Hi Guys,
I'll be posting an up to date BOM tonight, and I suggest that everyone wait until I get it posted. Nothing in the parts kits is labeled, but it's easy to tell what everything is once you have a proper BOM in hand.
It's mostly the caps that are easy to confuse since there are several different voltage ratings and it's important to get them in the right spot.
I'm glad the boards are all starting to arrive, and I'm looking forward to people's initial impressions!
Cheers,
Owen
I'll be posting an up to date BOM tonight, and I suggest that everyone wait until I get it posted. Nothing in the parts kits is labeled, but it's easy to tell what everything is once you have a proper BOM in hand.
It's mostly the caps that are easy to confuse since there are several different voltage ratings and it's important to get them in the right spot.
I'm glad the boards are all starting to arrive, and I'm looking forward to people's initial impressions!
Cheers,
Owen
specifically the 10u/50v (analogue higher V regs C20-21 C18 C17) and 10u/10v (digital lower V reg C9 C14 C19) parts, rest is straight forward given regimented stuffing.
important note, once you take one lot of parts out of the strip, measure with DMM to check value and stuff ALL of that strip before taking any others out. given better light tomorrow i'll post a pic of me with the pile of parts I have here haha over a grand worth of VCAPs and soon about the same in zfoils
important note, once you take one lot of parts out of the strip, measure with DMM to check value and stuff ALL of that strip before taking any others out. given better light tomorrow i'll post a pic of me with the pile of parts I have here haha over a grand worth of VCAPs and soon about the same in zfoils
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