effenberg0x0 Posted January 12, 2010 Report Share Posted January 12, 2010 Agreed. Had to opportunity to see the defacement part of it. Quote Link to comment Share on other sites More sharing options...
Holt Posted January 13, 2010 Report Share Posted January 13, 2010 Does anyone have a single side pcb layout they wish to share on this site?Holt Quote Link to comment Share on other sites More sharing options...
lysium Posted January 14, 2010 Report Share Posted January 14, 2010 hi all,is it possible to use LT1491 for the op-amp? coz i have few on my drawerthanks, Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 14, 2010 Report Share Posted January 14, 2010 is it possible to use LT1491 for the op-amp? coz i have few on my drawerThey use extremely low power which shows because they are much too slow. Their output drops above only 800Hz. They are also very noisy. Quote Link to comment Share on other sites More sharing options...
kvakva Posted January 16, 2010 Report Share Posted January 16, 2010 I was observing schematic of this power supply unit, and I would like to know how does it actually works? I can lightly understand how does it works, but can not apprehend details. There is a general description of this P.S.U. but, simply I would like to know more details. Is there any DETAILED description of this P.S.U.? I am especially interested about U1 voltage reference. I don`t understand how output of U1 gradually increases? What makes potential difference on the U1 plus and minus terminals to force output rise?Any additional explanation about this P.S.U. is welcome (some site, text, reply, picture, pdf document...).Best regards,ing. Sarkezi Michal.[email protected]P.S. sorry for my bad english. :) Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 16, 2010 Report Share Posted January 16, 2010 Is there any DETAILED description of this P.S.U.? I am especially interested about U1 voltage reference. I don`t understand how output of U1 gradually increases? What makes potential difference on the U1 plus and minus terminals to force output rise?When power is applied, D8 does not have enough voltage to conduct but the opamp has positive feedback from R5 nand R6 so it greatly amplifies the noise in the opamp until the output voltage reaches about 10V when the zener diode D8 begins to conduct.When pin 2 rises to +5.6V then the output is 11.2V. Quote Link to comment Share on other sites More sharing options...
dracu_n_dulap Posted January 17, 2010 Report Share Posted January 17, 2010 so.... i'm back again to be annoying ;Dto turn my psu into the 5A variant the transformer has to be 2x30V at how much amperes. Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 17, 2010 Report Share Posted January 17, 2010 so.... i'm back again to be annoying ;Dto turn my psu into the 5A variant the transformer has to be 2x30V at how much amperes.I don't know why you have two 30V windings on your transformer.30V makes a peak voltage of 42.4V that feeds the bridge rectifier and main filter capacitor. If the load on the project is 5A then its max power is 42.4V x 5A= 212W.Therefore the 30V transformer must be rated at 212VA or 7.07A or it will get too hot. Quote Link to comment Share on other sites More sharing options...
GrahamG Posted January 17, 2010 Report Share Posted January 17, 2010 So I decided to throw D15 away and replaced it with a peace of wire. Now I am able to get 30V with 3A.If someone has the same problem as I (The rectifier voltage is to high for the oamps with 44V) you can use D15 which should have only as much voltage as you need to get under the 44V. The voltage in my circuit is about 39.6V - 44V and nothing is damaged.I have just started with this project and am reading up on all the alternations/changes that have been made but I can't find "D15". Am I missing something in the schematics ? Quote Link to comment Share on other sites More sharing options...
dracu_n_dulap Posted January 17, 2010 Report Share Posted January 17, 2010 I don't know why you have two 30V windings on your transformer.30V makes a peak voltage of 42.4V that feeds the bridge rectifier and main filter capacitor. If the load on the project is 5A then its max power is 42.4V x 5A= 212W.Therefore the 30V transformer must be rated at 212VA or 7.07A or it will get too hot.7 A..............i understand a bit expensive to order but oki made a mistake writing the 2x30 i was thinking about something else and it doesn't have anything to do with electronics ;Dwas a way for me to say that i have 2 psutanks!good luck! :D Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 17, 2010 Report Share Posted January 17, 2010 I have just started with this project and am reading up on all the alternations/changes that have been made but I can't find "D15". Am I missing something in the schematics?I don't know whose schematic has D15. Mine shows a new 10V/1W zener diode that reduces the supply voltage to U3 but it does not have a part number and is missing on my latest parts list. Quote Link to comment Share on other sites More sharing options...
GrahamG Posted January 19, 2010 Report Share Posted January 19, 2010 audioguru - thanks for the reply. must be a mistake in the forum as i read every page on the lab psu and one article mentioned D15. Perhaps a different project. Quote Link to comment Share on other sites More sharing options...
lysium Posted January 19, 2010 Report Share Posted January 19, 2010 They use extremely low power which shows because they are much too slow. Their output drops above only 800Hz. They are also very noisy.Thanks audioguru for the answer Quote Link to comment Share on other sites More sharing options...
seba_031 Posted January 21, 2010 Report Share Posted January 21, 2010 So is it good to make the power supply by the original scheme and parts or not? Quote Link to comment Share on other sites More sharing options...
Biggy Boy Posted January 21, 2010 Report Share Posted January 21, 2010 Well according to all of the posts in this thread and I have read every single one,The answer is NO do not use the original schematic! Use the newer one posted in this forums thread.Glen Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 21, 2010 Report Share Posted January 21, 2010 So is it good to make the power supply by the original scheme and parts or not?1) It does not give 3A at 30V.2) It has many of its parts overloaded and operating at voltages higher than the max allowed voltage for them.3) It is not accurate and is not reliable. Quote Link to comment Share on other sites More sharing options...
seba_031 Posted January 22, 2010 Report Share Posted January 22, 2010 Can anyone here, who has made this circuit and it's working properly, send me the part list and PCB layout to my e-mail. And please if it's possible on the one-sided board. Thanks Quote Link to comment Share on other sites More sharing options...
shoaibasghar Posted January 22, 2010 Report Share Posted January 22, 2010 hello!i am also thinking about making it as my project for this semester. what i want to know is should i use the info provided in the .rar file by redwire on the first page of this discussion(all the info was updated on 30 dec 09). And does any one have single side PCB layout? If not then could anyone give some tip about making double sided pcb and how to print redwires circuit from EAGLE(i don't know how to use that software)also i dont know how you solder things on double PCB. and redwires design (the picture of the finalized circuit) looks on single sided PCB. is it so? Quote Link to comment Share on other sites More sharing options...
GrahamG Posted January 22, 2010 Report Share Posted January 22, 2010 shoaibasghar - i am busy making the PSU myself. My suggestion, if you have not got the facility to make DSPCB, is to route the board in Eagle on the copper side only and to use top layer tracks as "jumpers". This works well. They must be straight however. Quote Link to comment Share on other sites More sharing options...
shoaibasghar Posted January 22, 2010 Report Share Posted January 22, 2010 shoaibasghar - i am busy making the PSU myself. My suggestion, if you have not got the facility to make DSPCB, is to route the board in Eagle on the copper side only and to use top layer tracks as "jumpers". This works well. They must be straight however.u mean to say that i should make only one sided board and connect the upper sides by wires instead?if so will normal jumper wires do or i have to use thick ones. and which schematics etc are you using? one on first page by redwire? Quote Link to comment Share on other sites More sharing options...
GrahamG Posted January 22, 2010 Report Share Posted January 22, 2010 u mean to say that i should make only one sided board and connect the upper sides by wires instead?Exactly.That is how i do it all the time for making prototypes. You just have to remember to keep the top layer "jumpers" straight else you will be soldering in some weird looking wires. If you have to go around a corner then use top-straight, bottom-angled and the top-straight again.Also remember to make the vias for the top layer with at least a 0.8mm hole size and 1.6mm diameter else you will destroy the via when you drill it.....if so will normal jumper wires do or i have to use thick ones.normal UTP core is what I use. Only need heavy duty wire for high current tracks.and which schematics etc are you using? one on first page by redwire?I have down loaded the latest, the one with all the RED text. I havn't got much further other than to redo the schematic in Eagle, busy now with routing tracks from the netlist Quote Link to comment Share on other sites More sharing options...
vacana Posted January 25, 2010 Report Share Posted January 25, 2010 i planning to make a voltmeter and ammeter for this power supply, i will step down the output voltage from the power supply and step up the voltage from the shunt resistor using two opamps configured as differential amplifier.is the -1.3v from the power supply enough for the meter opamps?i will use tle2141 for the meter. Quote Link to comment Share on other sites More sharing options...
Holt Posted January 25, 2010 Report Share Posted January 25, 2010 I have just finished a double sidet pcb using the scematics from redwire, i have modifiet it a little, making the routes and soldering points a little wider to make it a bit more DIY friently, i used the laser print transfer metod from this link http://www.riccibitti.com/pcb/pcb.htm its a bit of a PITA to solder ic-sockets and some of the other components without "eyelet"connector pipes. i have the scematics on a PDF file (front, back and components) but i dont know how to upload them to the siteHolt Quote Link to comment Share on other sites More sharing options...
GrahamG Posted January 25, 2010 Report Share Posted January 25, 2010 I can' help you here as there seems to be no facility. Perhaps as we are all novice users you cannot do this. Quote Link to comment Share on other sites More sharing options...
redwire Posted January 26, 2010 Author Report Share Posted January 26, 2010 GrahamG and HoltLook below the message block and you will find >Additional Options... Click on that and you can attach certain files. Sometimes it will reject certain formats but if you zip them it is usually not a problem. Quote Link to comment Share on other sites More sharing options...
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