OZ6YM Posted January 27, 2016 Report Share Posted January 27, 2016 (edited) This print-layout has a "to thin" returnline for MAX power 3 Amp.You have to make a better layout, or make it stronger with a 0.6 m.m. wire, extra, between the end-point.A fine Lab. Supply, I have made 3 of them until now, working perfekt!!Good luck. Edited January 27, 2016 by OZ6YM Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 28, 2016 Report Share Posted January 28, 2016 OZ6YM,Which version of this project did you make:1) The original Greek kit with many overloaded parts and it cannot produce 30V at 3A?2) The improved circuit in the forums?3) The Chinese copy of the Greek kit? Quote Link to comment Share on other sites More sharing options...
OZ6YM Posted January 28, 2016 Report Share Posted January 28, 2016 I made nr. 2.My comment is for the print on the Picture... Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 29, 2016 Report Share Posted January 29, 2016 I do not like to look at a pcb that has nothing labelled. Quote Link to comment Share on other sites More sharing options...
OZ6YM Posted January 29, 2016 Report Share Posted January 29, 2016 I am talking about this project http://www.electronics-lab.com/project/0-30v-laboratory-power-supply/Look at the PCB...The return-line for MINUS or the GROUND-WIRE is to thin...Make it bigger to take 3 Amp at 30 Volt.That is my comment.......what a guru... Quote Link to comment Share on other sites More sharing options...
CBETO3AP Posted January 29, 2016 Author Report Share Posted January 29, 2016 HiI work on Hristo PCB, member of this community.http://diyfan.blogspot.com.es/2012/02/adjustable-lab-power-supply.htmlBy changing the shunt, as I feared, the current regulation is very slow, now I'm looking solution without increasing the shunt.No load through the PCB and is cut so. OZ6YM 1 Quote Link to comment Share on other sites More sharing options...
OZ6YM Posted January 29, 2016 Report Share Posted January 29, 2016 Ohh.. Yes... This i much better... Thanks...de OZ6YM, Palle Quote Link to comment Share on other sites More sharing options...
audioguru Posted January 29, 2016 Report Share Posted January 29, 2016 I am talking about this project http://www.electronics-lab.com/project/0-30v-laboratory-power-supply/Look at the PCB...The return-line for MINUS or the GROUND-WIRE is to thin...Make it bigger to take 3 Amp at 30 Volt.That is my comment.......what a guru...I have never seen this defective new copy of the original project before. It has all the errors of the original project and added some new errors. The parts numbering has been changed so it is difficult to say that a resistor is 1/4W but must be 1W and its value should be xxx. Many parts are overloaded and the opamps have a total supply voltage too high for them. Quote Link to comment Share on other sites More sharing options...
CBETO3AP Posted February 5, 2016 Author Report Share Posted February 5, 2016 woala Quote Link to comment Share on other sites More sharing options...
CBETO3AP Posted February 6, 2016 Author Report Share Posted February 6, 2016 Quote Link to comment Share on other sites More sharing options...
Mayoral Posted February 12, 2016 Report Share Posted February 12, 2016 (edited) Hi,Audioguru, would you mind point out where can I find the improved schematic of the Chinese (banggood) and Greek power supply kit?I have one of those kits and I would not mind expending few dollars to improve it ... or I may have the components in the shack.Thanks! Edited February 12, 2016 by Mayoral Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 12, 2016 Report Share Posted February 12, 2016 Many parts are changed or added so a new pcb is needed.Here are the latest parts list and schematic for the improved version: Quote Link to comment Share on other sites More sharing options...
Mayoral Posted February 15, 2016 Report Share Posted February 15, 2016 (edited) Thank you very much! I see what you mean, it is not only changing few component.... I have almost every component I may make it next new project ! Since I was curious I was digging the forums and the web an I came across a very similar schematics. In this one, Q1, R13 and R14 have been included back to "mitigate transient surge issue". Since you look pretty knowledgeable (and my knowledge that does not go that far), do you have an opinion in this incorporation? Will it affect the overall performance of the supply?Thanks in advance again for your time and comments. Edited February 15, 2016 by Mayoral Quote Link to comment Share on other sites More sharing options...
audioguru Posted February 15, 2016 Report Share Posted February 15, 2016 I did not look into the transient that might occur when the power is turned on or off. Q1 was originally placed to short the output of opamp U2 because the old TL081 original opamps had a problem called "Opamp Phase Inversion" when an input voltage became too close to the negative supply voltage when the negative supply collapsed first when the power was turned off. It would have caused the output of the opamp U2 to suddenly go as high as it can which is bad for the speaker. The new opamps do not have this problem.You can add Q1 and its resistors if you want. Quote Link to comment Share on other sites More sharing options...
Mayoral Posted February 15, 2016 Report Share Posted February 15, 2016 Thanks again! Quote Link to comment Share on other sites More sharing options...
shoown Posted March 9, 2016 Report Share Posted March 9, 2016 It seems so complex to make a pcb. Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 10, 2016 Report Share Posted March 10, 2016 There is (or was) a Greek kit available and today there is a Chinese copy of the Greek kit. The kits have a pcb. If you use a kit then you can cross your fingers and hope that one of its many overloaded parts do not fail soon. Quote Link to comment Share on other sites More sharing options...
reekoazil Posted March 27, 2017 Report Share Posted March 27, 2017 On 2/15/2016 at 9:14 AM, Mayoral said: Thank you very much! I see what you mean, it is not only changing few component.... I have almost every component I may make it next new project ! Since I was curious I was digging the forums and the web an I came across a very similar schematics. In this one, Q1, R13 and R14 have been included back to "mitigate transient surge issue". Since you look pretty knowledgeable (and my knowledge that does not go that far), do you have an opinion in this incorporation? Will it affect the overall performance of the supply? Thanks in advance again for your time and comments. Sir, Is it ok if I use a 30V from the secondary output of a transformer or It must be a 24V secondary output. Sorry I am new in understanding what a 28VAC transformer means. Quote Link to comment Share on other sites More sharing options...
audioguru Posted March 28, 2017 Report Share Posted March 28, 2017 I can buy a transformer with any voltage that I want. A 28VAC one or a 30VAC one will work in this modified circuit and the circuit will have a maximum regulated output of 30VDC at 3A. If you use a transformer that is 24VAC then the maximum regulated output from this modified circuit will be about 25VDC at 2.5A, and if the voltage and current controls are at maximum then the output will produce lots of unregulated ripple. Quote Link to comment Share on other sites More sharing options...
gixap92915 Posted January 7, 2023 Report Share Posted January 7, 2023 On 1/26/2016 at 8:45 AM, CBETO3AP said: Yes, I have been forced to change the shunt resistor. Now this place metal shunt 10A / 0.1V.Thus I am saving me 1.4V. Plus something like 0.5V to have 10 emiter resistor in parallel. Low Vdrop is because the shunt is bolted directly to the output. And the sensing cable to the out. Sir, I'm sorry but can you share the scheme you used? Thanks. Quote Link to comment Share on other sites More sharing options...
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