wall wart with snubber?
EZKC Dude: " ... If you look at the schematic richie00boy posted on his website, the snubber goes all the way across the two diodes and electrolytic caps. That's what I did here. Does anyone else care to chime in their opinion on this? ..."
Assuming you mean the cap @ C9 ?? ... what material? ... type of capacitor? ... poly? (I may have missed your materials list ... got links?)
You might consider a couple of extra connect points to ground at this location (C9) ... for dual snubbers to ground from the + & - rails = future addons or updates.
😉
EZKC Dude: " ... If you look at the schematic richie00boy posted on his website, the snubber goes all the way across the two diodes and electrolytic caps. That's what I did here. Does anyone else care to chime in their opinion on this? ..."
Assuming you mean the cap @ C9 ?? ... what material? ... type of capacitor? ... poly? (I may have missed your materials list ... got links?)
You might consider a couple of extra connect points to ground at this location (C9) ... for dual snubbers to ground from the + & - rails = future addons or updates.
😉
Dude, I placed that capacitor across the whole bridge in that way after careful optimisation. That is the best way to do it. It efficiently snubs the whole bridge.
I appreciate you are not using the full bridge option, but still the single cap should be sufficient to provide any snubbing. In all honesty the noise from such a lower power circuit is difficult to notice/find anyway.
The capacitor should be where it was before. It's useless where you have moved it between the big caps and the way you have run the traces off the big caps instead of the diodes.
As you have noticed it gets messy once you start trying to add a cap+resistor across each diode, and there is absolutely no need to do so.
So stick back with your earlier design (but fix the trace routing) and go make some music 🙂
I appreciate you are not using the full bridge option, but still the single cap should be sufficient to provide any snubbing. In all honesty the noise from such a lower power circuit is difficult to notice/find anyway.
The capacitor should be where it was before. It's useless where you have moved it between the big caps and the way you have run the traces off the big caps instead of the diodes.
As you have noticed it gets messy once you start trying to add a cap+resistor across each diode, and there is absolutely no need to do so.
So stick back with your earlier design (but fix the trace routing) and go make some music 🙂
The well regulated wall wart
At this point I would like to request of EZKCDude a summary of links, updates, materials list, etc. for this well regulated wall wart filter design.
Got links to latest schematic and board layout, etc. ... got the latest materials list ?
(I have: http://www.cellandtissue.com/ezdac/schematic.pdf and http://www.diyaudio.com/forums/attachment.php?s=&postid=943401&stamp=1150674134 as the most recent versions.)
At this point I would like to request of EZKCDude a summary of links, updates, materials list, etc. for this well regulated wall wart filter design.
Got links to latest schematic and board layout, etc. ... got the latest materials list ?
(I have: http://www.cellandtissue.com/ezdac/schematic.pdf and http://www.diyaudio.com/forums/attachment.php?s=&postid=943401&stamp=1150674134 as the most recent versions.)
Well, if the consensus is that I go back to the last version (http://www.diyaudio.com/forums/attachment.php?s=&postid=953969&stamp=1152022977) of the PCB, I will do that. It sure seemed simpler that way. FastEddy, no problem, I will post a schematic (although it is going to be pretty much like richieboy's), PCB, and materials list (which I need to put together) hopefully later tonight, if I get the chance.
By the way, to FastEddy, the first link you posted in your last reply was for a DAC that is my long-term project. This PSU is the first step, but I think it was definitely worth doing, even if it is not the most original design. I have learned quite a bit about PCB design from you and the others (richieboy, AndrewT, and zuus), and tackling the entire DAC at once as a newbie would probably have been insanity on my part. O.k., that's it for now. Gotta get back to my day job.
By the way, to FastEddy, the first link you posted in your last reply was for a DAC that is my long-term project. This PSU is the first step, but I think it was definitely worth doing, even if it is not the most original design. I have learned quite a bit about PCB design from you and the others (richieboy, AndrewT, and zuus), and tackling the entire DAC at once as a newbie would probably have been insanity on my part. O.k., that's it for now. Gotta get back to my day job.
Further changes & upgrades?
Looking good so far:
1) So, is it possible to get a link to a graphic image rather than a .pdf file? This would make it easier for some of us old timers to propose modifications (as some of us can't get it up to edit postscript incapsulated images without buying more software and suffering through the learning curve.)
2) Have you made any boards yet? Will you do so? Would you consider letting some of us have some ($$ pre paid, of course)?
I personally don't want to crank up the old sludge tanks and run off a few myself = too much work, too much mess ... and I might actually have another use for these as prototype for a commercial project ... our catalog at 3dotaudio.com needs some kits for sale, etc.
Looking good so far:
1) So, is it possible to get a link to a graphic image rather than a .pdf file? This would make it easier for some of us old timers to propose modifications (as some of us can't get it up to edit postscript incapsulated images without buying more software and suffering through the learning curve.)
2) Have you made any boards yet? Will you do so? Would you consider letting some of us have some ($$ pre paid, of course)?
I personally don't want to crank up the old sludge tanks and run off a few myself = too much work, too much mess ... and I might actually have another use for these as prototype for a commercial project ... our catalog at 3dotaudio.com needs some kits for sale, etc.
see the customer base?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=82305&perpage=10&pagenumber=1 ... and check out page 2 ...
This is just one small area where ezkcdude's project has value ... = effects generators & tone control sub-modules for the performers on stage ... electronically, a notoriously noisey environment.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=82305&perpage=10&pagenumber=1 ... and check out page 2 ...
This is just one small area where ezkcdude's project has value ... = effects generators & tone control sub-modules for the performers on stage ... electronically, a notoriously noisey environment.
Re: Further changes & upgrades?
1->Yes, I can import the PDF into photoshop and export it from there. What format would you like (jpeg, eps, gif?)
2->I haven't made boards. I am planning to get the mini-board service from ExpressPCB, which is $53+shipping for three boards. I could you send you a board (at cost) if you want to try it out. If you'd like to run some tests or something, that would be cool.
The mini-board does not include solder mask or silkscreen. If it works though, I could order the standard boards which do include these (at higher cost, of course). Maybe we could do a group buy if there was enough interest.
As a side note, I noticed you sell the SqueezeBox at that website. I'm a huge fan, and the reason I got into this whole mess is because since I got the SB3, I've been listening to more music than ever in my life. I want to eventually have an entire DIY system built around it. I already have DIY speakers from several years back, so now I'm working on the DAC. When that's finished I'll move onto building an amp.
FastEddy said:
1->Yes, I can import the PDF into photoshop and export it from there. What format would you like (jpeg, eps, gif?)
2->I haven't made boards. I am planning to get the mini-board service from ExpressPCB, which is $53+shipping for three boards. I could you send you a board (at cost) if you want to try it out. If you'd like to run some tests or something, that would be cool.
The mini-board does not include solder mask or silkscreen. If it works though, I could order the standard boards which do include these (at higher cost, of course). Maybe we could do a group buy if there was enough interest.
As a side note, I noticed you sell the SqueezeBox at that website. I'm a huge fan, and the reason I got into this whole mess is because since I got the SB3, I've been listening to more music than ever in my life. I want to eventually have an entire DIY system built around it. I already have DIY speakers from several years back, so now I'm working on the DAC. When that's finished I'll move onto building an amp.
I've also put together a sample parts list. These are just suggestions, of course, but these should all have the correct pitch, lead diameters and so forth for the current design.
I forgot to add the regulators to the parts list:
U1 "1.5A, adj reg positive" LM317TNS-ND $1.79 1
U2 "1.5A, adj reg negative" LM337TNS-ND $2.06 1
U1 "1.5A, adj reg positive" LM317TNS-ND $1.79 1
U2 "1.5A, adj reg negative" LM337TNS-ND $2.06 1
Re: see the customer base?
Fair play to the Dude for coming up with his board and learning a lot along the way, I'm really happy he's achieved that. Questioning why others have done something is a great way to learn.
But you might have noticed he actually copied both my schematic and PCB in pretty much every way, so I find it slightly cheeky you ignore my boards when discussing commercial applications 😉 Granted the circuit is quite generic, but still I hope you can see my point 🙂
Maybe there is some way we can work something out? 🙂 But if you want to get a board of the Dude I can appreciate that, you both being in the same country etc.
FastEddy said:
Fair play to the Dude for coming up with his board and learning a lot along the way, I'm really happy he's achieved that. Questioning why others have done something is a great way to learn.
But you might have noticed he actually copied both my schematic and PCB in pretty much every way, so I find it slightly cheeky you ignore my boards when discussing commercial applications 😉 Granted the circuit is quite generic, but still I hope you can see my point 🙂
Maybe there is some way we can work something out? 🙂 But if you want to get a board of the Dude I can appreciate that, you both being in the same country etc.
Richie, I totally agree with you. Without your advice (and that of the others), I wouldn't have the board looking like this. Just take a look at the "evolution" of my design throughout this thread.
That said, this is supposed to be a DIY website. I think it would be unfair for me (or anyone else, really) to profit from the design put forth in this thread, especially since that wasn't my original intention. If there is demand for a group buy, I'd be willing to do that. If people want to use the design and make their own board for themselves, that's fine, too. As for commercial applications, it seems to me that is contrary to the entire concept of this forum. Obviously, I can't prevent anyone from "taking" the design and selling it without my permission (or at least, giving me credit), but I hope that would not happen.
On the other hand...There is an argument to be made that if there is enough demand for this or any other design on the forum, that some nominal fee could be charged to cover the cost of someone's time and effort to produce the board. This would be analogous to the way RedHat profits from supporting and distributing Linux, which is open-source, and supposed to be free. What they sell is their support and packaging of the software. I think we can cross this bridge when we come to it, if necessary.
Richie, just out of curiosity, do you actually sell your board? If so, for how much (in USD) and what is the demand for it?
That said, this is supposed to be a DIY website. I think it would be unfair for me (or anyone else, really) to profit from the design put forth in this thread, especially since that wasn't my original intention. If there is demand for a group buy, I'd be willing to do that. If people want to use the design and make their own board for themselves, that's fine, too. As for commercial applications, it seems to me that is contrary to the entire concept of this forum. Obviously, I can't prevent anyone from "taking" the design and selling it without my permission (or at least, giving me credit), but I hope that would not happen.
On the other hand...There is an argument to be made that if there is enough demand for this or any other design on the forum, that some nominal fee could be charged to cover the cost of someone's time and effort to produce the board. This would be analogous to the way RedHat profits from supporting and distributing Linux, which is open-source, and supposed to be free. What they sell is their support and packaging of the software. I think we can cross this bridge when we come to it, if necessary.
Richie, just out of curiosity, do you actually sell your board? If so, for how much (in USD) and what is the demand for it?
some links
Now, that I'm getting close to getting this board made, I've decided to put the links directly on my personal (non-commercial) website. From now on, all updates (schematics, pcb, pictures, etc) will be posted there.
Schematic:
http://www.cellandtissue.com/ezdac/dual_supply_schematic.pdf
or
http://www.cellandtissue.com/ezdac/dual_supply_schematic.png
PCB:
http://www.cellandtissue.com/ezdac/dual_supply_board.pdf
or
http://www.cellandtissue.com/ezdac/dual_supply_board.png
Materials:
http://www.cellandtissue.com/ezdac/dual_supply_materials.html
Some issues:
I think the output caps on the regs should be labeled polarized, according to the data sheets. I'm not sure it matters that much, but I thought I'd point it out. Certainly, if polarized caps are used, they need to be oriented properly, so I may modify the schematic and board to reflect this.
The resistor values for the regs have been set to output +/-15 V.
As per FastEddy's request, I posted png files. I tried posting jpegs, but I think my school's server doesn't allow it anymore, for some insane security reasons.
Now, that I'm getting close to getting this board made, I've decided to put the links directly on my personal (non-commercial) website. From now on, all updates (schematics, pcb, pictures, etc) will be posted there.
Schematic:
http://www.cellandtissue.com/ezdac/dual_supply_schematic.pdf
or
http://www.cellandtissue.com/ezdac/dual_supply_schematic.png
PCB:
http://www.cellandtissue.com/ezdac/dual_supply_board.pdf
or
http://www.cellandtissue.com/ezdac/dual_supply_board.png
Materials:
http://www.cellandtissue.com/ezdac/dual_supply_materials.html
Some issues:
I think the output caps on the regs should be labeled polarized, according to the data sheets. I'm not sure it matters that much, but I thought I'd point it out. Certainly, if polarized caps are used, they need to be oriented properly, so I may modify the schematic and board to reflect this.
The resistor values for the regs have been set to output +/-15 V.
As per FastEddy's request, I posted png files. I tried posting jpegs, but I think my school's server doesn't allow it anymore, for some insane security reasons.
PNG is a much better format for schematics and PCBs as it doesn't add nasty blur everywhere because of lossy compression.
toward better wall wart regulation
ezkcdude: Ok!! You did quite a lot of work in a very short amount of time. ... and all of it looks very good ... (my advise being worth just about what you are paying for it = $0.00)
A long winded discorse follows ...
Materials list / more suggestions:
1) Rectifier diodes could be 1N4003. Note that 1N4001 is rated 50 VDC, 1N4003 is rated 200 VDC ... FYI: Fairchild diode part numbering scheme is easy to figure out (references below) ... and costs are not important here as all these diodes are about the same $$ unless you are buying hundreds at a time. Other specs are comparable throughout the Fairchild scheme = response time is equal for all series part numbers. All diode manufacturers have equivelents to these Fairchild part numbers. (There is enough down stream regulation that Schottky type diodes need not be considered.)
2) Since it may be possible (in the case of a near lightning strike, strong RF signals, accidental plug into 240 VAC, etc., etc.) for spiking voltages across the input to exceed the expected, nominal 50 Volts DC or AC (peak to peak), it is good practice to rate all components 2.5 to 4 times the nominal voltage at the input and at least 1.5 to 2 times the nominal voltages expected beyond the first stage of internal loads (beyond resistors [or coils] R1, R2). Therefore it is suggested that C1A, C2A and C9 plus R1 and R2 be rated above 100 to 150 Volts.
3) Any and all components down stream to the chip regulators U1 and U2 ... from that first stage of load baring resistance ... should be rated above 100 Volts (DC or AC) including C1B, C2B, F1, F2, C3 & C6. All of the rest should carry ratings above 35 to 50 VDC. (All of this may seem like overkill, but as they say, s**t happens.)
4) It might be possible to use one fuse (or circuit breaker) between the AC / DC input at AC1 instead of dual fuses F1 & F2. (Fuses have their own set of questions, depending on the type used, and can have a small noise contribution of their own, being a type of resistor.) Personally, I would prefer a 1.25 to 1.5 Amp, bat handled circuit breaker ahead of the input at AC1 instead of two 1 Amp fuses == works like a master power on/off switch ... but I would like to see the solder pads and extra traces remain on the PCB.
5) With the exception of C9, all capacitors from AC1 & AC2 through to the chip regulators U1 & U2 can be polarized electrolitic types. (C9 "snubbs" the whole power chain through to the chip regulator inputs and C5 and C8 can "snub" the outputs.)
6) Likewise, any resistors from AC1 & AC2 to the chip regulator inputs of U1 & U2 can be of any type, carbon or whatever ... but resistors R3, R4, R5 and R6 should be of a low noise type like metal film or other "high tech" construction ... as there is a potential for a noise contribution from carbon resistors ... but you already knew this as per the materials list.
7) And of course C4, C5, C7 & C8 should be plastic "poly" or Tantalum ... but you already knew this as indicated in your material lists.
8) Power values for any resistors (or coils [inductors]) in the power chain should be compatible with the "worst case" requirement. In this case R1 & R2 should be 5 Watts or more, combined and of small resistance value ... or use coils instead to "load" the capcitors ahead of the chip regulators. Power values for the voltage reference network, R3, R4, R5 & R6 can be 1/4 Watt or less as no significant current should pass here as long as the R3 & R4 combined are >>= 1000 ohms (~=1.2k, combined) ... as you indicate in the material list.
9) Although National Semi insists that the chip regulators (LM317) can handle up to 1500 milliAmps, this would require very large heat sinks and in any case should be considered as a "worst case" scenario, National apparently believing that "infinite" heat sinks are manufacturable. Us mortals should consider that the LM317 should easily handle 500 milliAmps each, with a generous heat sink. (Note that by using LM338, a more raesonably sized heat sink will do nicely.) Note that any heat sink on these chip regulators should not be connected to any ground point. ...
10) If fixed regulators, like -7815 & 7915 types, were used, a) the heat sinks should be tied to ground (the ground plane, board copper acting as added heat sink) and b) the whole network R3, R4, R5 & R6 & C4 & C7 could be removed. (!) ... But I would not remove any of the solder pads and associated traces = making the boards usable for either type of chip regulator. (See references to 7805 through 7818 and 7905 thru 7918 below =all available for about $5 per ... or much less in qty.)
11) Ferrite Beads may be placed close to the input legs of the chip regulators U1 & U2 if the need seems great ... unless coils are used instead of R1 & R2 resistor. This can contribute to chip regulator effesencies = less heat and better regulation, less noise, etc. ...
The circuit / more suggestions:
Generally, the circuit is fine as you present it and follows generally accepted practices for half wave and full wave rectifying power supplies. You are not actually reinventing any new wheels here, except for making accomodations to the stricter requirements of quality, high end audio. ... And with the boards are fully stuffed with components, the finished device can be used to filter unregulated AC wall warts or transformers OR poorly regulated DC wall warts.
Because of the care taken in component selection, the overall efficiencies of this linear power filter /supply should be quite good.
Provided that the resistors R4 & R6 are carefully selected (assuming R3 & R5 are fixed values), input voltages could range from 12 Volts (7.5 VAC (~= 12 V peak to peak or 12 VDC) to 30 VAC (~= 50 V peak to peak or 50 VDC) across AC1, AC2 and produce well filtered, well regulated, split outputs of +/- 5 VDC to +/- 18 VDC ... !
(I don't recommend using variable resistor at R4 or R6 as all adjustable resistors have the potential of making a noise contribution. ... but you already have discovered this.)
References:
http://en.wikipedia.org/wiki/Schottky_diode
http://www.fairchildsemi.com/ds/1N/1N4004.pdf
http://www.national.com/pf/LM/LM317.html & http://www.national.com/pf/LM/LM338.html
http://en.wikipedia.org/wiki/Ferrite_bead & http://en.wikipedia.org/wiki/Inductor
http://www.fairchildsemi.com/pf/LM/LM7815.html & http://www.fairchildsemi.com/pf/LM/LM7905.html (7915 info)
More on the PCB later ... if you can stand these long winded articles.
ezkcdude: Ok!! You did quite a lot of work in a very short amount of time. ... and all of it looks very good ... (my advise being worth just about what you are paying for it = $0.00)
A long winded discorse follows ...
Materials list / more suggestions:
1) Rectifier diodes could be 1N4003. Note that 1N4001 is rated 50 VDC, 1N4003 is rated 200 VDC ... FYI: Fairchild diode part numbering scheme is easy to figure out (references below) ... and costs are not important here as all these diodes are about the same $$ unless you are buying hundreds at a time. Other specs are comparable throughout the Fairchild scheme = response time is equal for all series part numbers. All diode manufacturers have equivelents to these Fairchild part numbers. (There is enough down stream regulation that Schottky type diodes need not be considered.)
2) Since it may be possible (in the case of a near lightning strike, strong RF signals, accidental plug into 240 VAC, etc., etc.) for spiking voltages across the input to exceed the expected, nominal 50 Volts DC or AC (peak to peak), it is good practice to rate all components 2.5 to 4 times the nominal voltage at the input and at least 1.5 to 2 times the nominal voltages expected beyond the first stage of internal loads (beyond resistors [or coils] R1, R2). Therefore it is suggested that C1A, C2A and C9 plus R1 and R2 be rated above 100 to 150 Volts.
3) Any and all components down stream to the chip regulators U1 and U2 ... from that first stage of load baring resistance ... should be rated above 100 Volts (DC or AC) including C1B, C2B, F1, F2, C3 & C6. All of the rest should carry ratings above 35 to 50 VDC. (All of this may seem like overkill, but as they say, s**t happens.)
4) It might be possible to use one fuse (or circuit breaker) between the AC / DC input at AC1 instead of dual fuses F1 & F2. (Fuses have their own set of questions, depending on the type used, and can have a small noise contribution of their own, being a type of resistor.) Personally, I would prefer a 1.25 to 1.5 Amp, bat handled circuit breaker ahead of the input at AC1 instead of two 1 Amp fuses == works like a master power on/off switch ... but I would like to see the solder pads and extra traces remain on the PCB.
5) With the exception of C9, all capacitors from AC1 & AC2 through to the chip regulators U1 & U2 can be polarized electrolitic types. (C9 "snubbs" the whole power chain through to the chip regulator inputs and C5 and C8 can "snub" the outputs.)
6) Likewise, any resistors from AC1 & AC2 to the chip regulator inputs of U1 & U2 can be of any type, carbon or whatever ... but resistors R3, R4, R5 and R6 should be of a low noise type like metal film or other "high tech" construction ... as there is a potential for a noise contribution from carbon resistors ... but you already knew this as per the materials list.
7) And of course C4, C5, C7 & C8 should be plastic "poly" or Tantalum ... but you already knew this as indicated in your material lists.
8) Power values for any resistors (or coils [inductors]) in the power chain should be compatible with the "worst case" requirement. In this case R1 & R2 should be 5 Watts or more, combined and of small resistance value ... or use coils instead to "load" the capcitors ahead of the chip regulators. Power values for the voltage reference network, R3, R4, R5 & R6 can be 1/4 Watt or less as no significant current should pass here as long as the R3 & R4 combined are >>= 1000 ohms (~=1.2k, combined) ... as you indicate in the material list.
9) Although National Semi insists that the chip regulators (LM317) can handle up to 1500 milliAmps, this would require very large heat sinks and in any case should be considered as a "worst case" scenario, National apparently believing that "infinite" heat sinks are manufacturable. Us mortals should consider that the LM317 should easily handle 500 milliAmps each, with a generous heat sink. (Note that by using LM338, a more raesonably sized heat sink will do nicely.) Note that any heat sink on these chip regulators should not be connected to any ground point. ...
10) If fixed regulators, like -7815 & 7915 types, were used, a) the heat sinks should be tied to ground (the ground plane, board copper acting as added heat sink) and b) the whole network R3, R4, R5 & R6 & C4 & C7 could be removed. (!) ... But I would not remove any of the solder pads and associated traces = making the boards usable for either type of chip regulator. (See references to 7805 through 7818 and 7905 thru 7918 below =all available for about $5 per ... or much less in qty.)
11) Ferrite Beads may be placed close to the input legs of the chip regulators U1 & U2 if the need seems great ... unless coils are used instead of R1 & R2 resistor. This can contribute to chip regulator effesencies = less heat and better regulation, less noise, etc. ...
The circuit / more suggestions:
Generally, the circuit is fine as you present it and follows generally accepted practices for half wave and full wave rectifying power supplies. You are not actually reinventing any new wheels here, except for making accomodations to the stricter requirements of quality, high end audio. ... And with the boards are fully stuffed with components, the finished device can be used to filter unregulated AC wall warts or transformers OR poorly regulated DC wall warts.
Because of the care taken in component selection, the overall efficiencies of this linear power filter /supply should be quite good.
Provided that the resistors R4 & R6 are carefully selected (assuming R3 & R5 are fixed values), input voltages could range from 12 Volts (7.5 VAC (~= 12 V peak to peak or 12 VDC) to 30 VAC (~= 50 V peak to peak or 50 VDC) across AC1, AC2 and produce well filtered, well regulated, split outputs of +/- 5 VDC to +/- 18 VDC ... !
(I don't recommend using variable resistor at R4 or R6 as all adjustable resistors have the potential of making a noise contribution. ... but you already have discovered this.)
References:
http://en.wikipedia.org/wiki/Schottky_diode
http://www.fairchildsemi.com/ds/1N/1N4004.pdf
http://www.national.com/pf/LM/LM317.html & http://www.national.com/pf/LM/LM338.html
http://en.wikipedia.org/wiki/Ferrite_bead & http://en.wikipedia.org/wiki/Inductor
http://www.fairchildsemi.com/pf/LM/LM7815.html & http://www.fairchildsemi.com/pf/LM/LM7905.html (7915 info)
More on the PCB later ... if you can stand these long winded articles.
Thanks. I have definitely "grown up" during this thread.
Moving on...I think we need to be careful here not to overspecify. With higher voltage and current ratings comes more expensive and more importantly, larger components size. At some point, the resistors and caps (probably the major concern) will be physically too big. FastEddy, you can print out the png, it is drawn exactly to scale. If you already have a supply of some of these parts, can you just see if they fit the current board, in terms of pitch, lead diameters, body outlines, etc? That would be helpful. I'm sure the board will fit the parts I have listed, but I don't have much else on hand to try out, and I don't really have the time to sift through the entire digi-key catalog. I think the board can accomodate fairly beefy components, but obviously there are limits.
If people have recommendations for specific components, please give me a part number (digikey, mouser, newarkinone), and I will look it up and see if the specs fit the current board design. No problem.
Edit: I did some quick checking. With the caps, if we go to 50V rating, then we should lower the capacitance to 3300uF, and if we use 100V, then the capacitance is 1000uF for the same body outline size. This is just to give an idea. It looks like we may be safe going to the higher voltages, but may have to give up a little in terms of capacitance.
Moving on...I think we need to be careful here not to overspecify. With higher voltage and current ratings comes more expensive and more importantly, larger components size. At some point, the resistors and caps (probably the major concern) will be physically too big. FastEddy, you can print out the png, it is drawn exactly to scale. If you already have a supply of some of these parts, can you just see if they fit the current board, in terms of pitch, lead diameters, body outlines, etc? That would be helpful. I'm sure the board will fit the parts I have listed, but I don't have much else on hand to try out, and I don't really have the time to sift through the entire digi-key catalog. I think the board can accomodate fairly beefy components, but obviously there are limits.
If people have recommendations for specific components, please give me a part number (digikey, mouser, newarkinone), and I will look it up and see if the specs fit the current board design. No problem.
Edit: I did some quick checking. With the caps, if we go to 50V rating, then we should lower the capacitance to 3300uF, and if we use 100V, then the capacitance is 1000uF for the same body outline size. This is just to give an idea. It looks like we may be safe going to the higher voltages, but may have to give up a little in terms of capacitance.
wall wart materials list
More notes on material list options.
from: http://www.cellandtissue.com/ezdac/dual_supply_materials.html
D1, D2 50V-1A 1N4001GDICT-ND ....... suggest using 1N4003 = 200 V.
C1,C2 4700 uF, 25V 565-1068-ND ....... suggest using higher voltage 35 or 50 V.
(also the need for this much uF may be overkill, 1000 uF should be plenty)
R1,R2 33R metal film, 1/4W, 1% P33.0CACT-ND ... metal film may not be required, 5 watts suggested.
F1,F2 125V, 1A F868-ND ...... or use single breaker at AC1 input.
R3,R5 100R metal film, 1/4W, 1% P100CACT-ND ..... N/C
R4,R6 1.1K metal film, 1/4W, 1% P1.10KCACT-ND ... N/C
C3,C6 10uF tant, 25V, 10% 399-3565-ND .... or 50 V., 10 to 20 uF Plastic Poly Cap.
C5,C8 10uF tant, 16V, 10% 399-3563-ND ..... or 50 V., 20 to 50 uF Plastic Ploy Cap.
C4,C7 1uF tant, 25V, 10% 399-3528-ND ... N/C or 35 V.
C9 100nF metal polyester, 250V, 10% P10967-ND ... actually as a snubbing cap, this value may be high. (small value metal poly caps paralleled with large electrolitic or Tant caps work better at higher freq filtering.) ... but N/C is fine.
U1 1.5A adj pos reg LM317TNS-ND ... N/C
U2 1.5A adj neg reg LM337TNS-ND ... N/C
Heat sinks ??
........
See the previous notes about using Fairchild 7805 / 7905, 7809 / 7909, 7812 / 7912, 7815 / 7915 or 7818 / 7918 as fixed voltage regulators.
Also added references:
The Op Amp Cookbook by Don Lancaster (circa 1975) and more recent books about using adjustable and fixed voltage chip regulators. FYI: all of these linear chip regulator designs are derived from original work done with the (very old) uA741 op amp from Fairchild and National.
More notes on material list options.
from: http://www.cellandtissue.com/ezdac/dual_supply_materials.html
D1, D2 50V-1A 1N4001GDICT-ND ....... suggest using 1N4003 = 200 V.
C1,C2 4700 uF, 25V 565-1068-ND ....... suggest using higher voltage 35 or 50 V.
(also the need for this much uF may be overkill, 1000 uF should be plenty)
R1,R2 33R metal film, 1/4W, 1% P33.0CACT-ND ... metal film may not be required, 5 watts suggested.
F1,F2 125V, 1A F868-ND ...... or use single breaker at AC1 input.
R3,R5 100R metal film, 1/4W, 1% P100CACT-ND ..... N/C
R4,R6 1.1K metal film, 1/4W, 1% P1.10KCACT-ND ... N/C
C3,C6 10uF tant, 25V, 10% 399-3565-ND .... or 50 V., 10 to 20 uF Plastic Poly Cap.
C5,C8 10uF tant, 16V, 10% 399-3563-ND ..... or 50 V., 20 to 50 uF Plastic Ploy Cap.
C4,C7 1uF tant, 25V, 10% 399-3528-ND ... N/C or 35 V.
C9 100nF metal polyester, 250V, 10% P10967-ND ... actually as a snubbing cap, this value may be high. (small value metal poly caps paralleled with large electrolitic or Tant caps work better at higher freq filtering.) ... but N/C is fine.
U1 1.5A adj pos reg LM317TNS-ND ... N/C
U2 1.5A adj neg reg LM337TNS-ND ... N/C
Heat sinks ??
........
See the previous notes about using Fairchild 7805 / 7905, 7809 / 7909, 7812 / 7912, 7815 / 7915 or 7818 / 7918 as fixed voltage regulators.
Also added references:
The Op Amp Cookbook by Don Lancaster (circa 1975) and more recent books about using adjustable and fixed voltage chip regulators. FYI: all of these linear chip regulator designs are derived from original work done with the (very old) uA741 op amp from Fairchild and National.
Can you give me some part numbers here? I doubt any 5W resistor will fit in the space I have provided on the board. If you can be more specific about components (part numbers, please), then we can go from there. Otherwise, it's just too much work for me.
too big??
ezkcdude: " ... I think we need to be careful here not to overspecify. With higher voltage and current ratings comes more expensive and more importantly, larger components size. At some point, the resistors and caps (probably the major concern) will be physically too big. ..."
Yes you are correct about the sizes as voltage rating goes up.
Note that you may be using to much capacity in C1A, C1B, C2A & C2B ... so by reducing the size (to maybe 500 uF or 1000 uF) the voltage rating can be increased without increasing physical size too much. Considering that the (total) voltage potential might exceed 250 volts In the case of a short circuit from European power outlet ... oops, get the fire extinguisher. For Kits and DIY, we may not worry too much, but a lawyer might get a hold of one of these ... Is 100 volts too much to ask? ... how about 50 volts.
ezkcdude: " ... I think we need to be careful here not to overspecify. With higher voltage and current ratings comes more expensive and more importantly, larger components size. At some point, the resistors and caps (probably the major concern) will be physically too big. ..."
Yes you are correct about the sizes as voltage rating goes up.
Note that you may be using to much capacity in C1A, C1B, C2A & C2B ... so by reducing the size (to maybe 500 uF or 1000 uF) the voltage rating can be increased without increasing physical size too much. Considering that the (total) voltage potential might exceed 250 volts In the case of a short circuit from European power outlet ... oops, get the fire extinguisher. For Kits and DIY, we may not worry too much, but a lawyer might get a hold of one of these ... Is 100 volts too much to ask? ... how about 50 volts.
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