tag:blogger.com,1999:blog-7057630065429233264.post1597088925738280389..comments2024-03-28T10:51:44.181+01:00Comments on Paul's DIY electronics blog: My New Power Supply Design Project Part 3paulvhttp://www.blogger.com/profile/11421488581167758443noreply@blogger.comBlogger28125tag:blogger.com,1999:blog-7057630065429233264.post-85305298880483080702024-03-28T10:51:44.181+01:002024-03-28T10:51:44.181+01:00Sandy, that constant current is there to improve t...Sandy, that constant current is there to improve the regulation at low voltages and currents.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-86632984522572394262024-03-28T10:26:42.624+01:002024-03-28T10:26:42.624+01:00bumping it again, Hi Paul, I have a question, what...bumping it again, Hi Paul, I have a question, what is the purpose of 10mA current sync. indicated in the power section of T2, Can't see that in T3 power section, is this required for T3 (meant for higher currents) also? Thanks!Sandynoreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-54858834748197602962023-06-22T06:17:08.855+02:002023-06-22T06:17:08.855+02:00Hi Paul, I have a question, what is the purpose of...Hi Paul, I have a question, what is the purpose of 10mA current sync. indicated in the power section of T2, Can't see that in T3 power section, is this required for T3 (meant for higher currents) also? Thanks!Sandynoreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-19294382751637930152022-12-09T14:46:35.946+01:002022-12-09T14:46:35.946+01:00Everything is as I posted it. No changes, so no us...Everything is as I posted it. No changes, so no use of a DAC or a controller.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-53998373811335420782022-12-09T13:50:00.220+01:002022-12-09T13:50:00.220+01:00hi paul, so as i understand you are changing the v...hi paul, so as i understand you are changing the v ref voltage? so the schematics are the same but you are ditching the reference voltage and sing the one from the dac instead?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-30311433555319542502022-02-21T21:01:00.996+01:002022-02-21T21:01:00.996+01:00Hi Anonymous, yes I did try that and used a simple...Hi Anonymous, yes I did try that and used a simple 10-bit DAC to control the reference voltages for the voltage and current Opamps. I was pleasantly surprised how well and precise that worked. I did not see the need for filtering.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-79591571848453996302022-02-21T12:58:51.113+01:002022-02-21T12:58:51.113+01:00Hi Paul,
Thanks for all this nice piece of info ...Hi Paul,<br /><br /> Thanks for all this nice piece of info on cc/cv psu design.<br /> I am looking to build a minimal mcu controlled bench psu just for fun and I really like your design process.<br /> In order to control voltage and current control setting from an mcu dac how would you alter the control part of the schematic? Would you bypass voltage reference totally and use the dac ouput as a voltage reference instead? Wouldn't this require proper filtering? Have you experimented with such a setup and where you happy with the results?<br /><br />Thanks :)Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-11901164140149483372019-01-18T09:49:04.173+01:002019-01-18T09:49:04.173+01:00Iqbal, my schematic capturing package (DipTrace) d...Iqbal, my schematic capturing package (DipTrace) does not allow me to put everything in one schematic. It goes way beyond the number of allowable interconnects, and I already use the upgraded version. Besides, it will be impossible to see printed on A4 or letter size paper. <br /><br />By using the interconnect naming conventions across the different schematics, it does not matter for a board layout. I made my own layout from the schematic diagrams as they are published.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-89706005333173269032019-01-18T09:43:51.651+01:002019-01-18T09:43:51.651+01:00Igbal, the diode across the opamps limit the excur...Igbal, the diode across the opamps limit the excursion towards the power-rail, causing saturation of the output section and hence will increase the overall speed. The R-C network is used to tune the frequency response. Look at the simulation section for more information.<br /><br />I use the 317 in a constant current mode, supplying the TL431 to arrive at a very stable reference at minimal cost. You could do that with either one of them, it's just what I fancied at the time.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-22890775011089054552019-01-17T14:59:00.610+01:002019-01-17T14:59:00.610+01:00Will you please provide a full schematic? All in o...Will you please provide a full schematic? All in one? maybe even the original files? You can send me personally through mail if you don't want everybody to find it. I want to make my own PCB with it with different DAC and ADC.Anonymoushttps://www.blogger.com/profile/03152912334734405370noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-91747273876548793372018-07-31T16:32:24.013+02:002018-07-31T16:32:24.013+02:00Hey Paul!
Why are you using the LM317 with TL431?...Hey Paul!<br /><br />Why are you using the LM317 with TL431? Why not just TL431?<br /><br />ThannksAnonymoushttps://www.blogger.com/profile/03152912334734405370noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-36488274430128695832018-07-28T18:52:23.466+02:002018-07-28T18:52:23.466+02:00Thank you so much for sharing this great blog.Very...Thank you so much for sharing this great blog.Very inspiring and helpful too.Hope you continue to share more of your ideas.I will definitely love to read. <a href="https://5productreviews.com/best-whole-house-power-surge-protectors/" rel="nofollow">best-whole-house-power-surge-protectors</a><br />Furkhundababy1https://www.blogger.com/profile/15781622677426062096noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-69104522741110982522018-06-29T09:10:21.633+02:002018-06-29T09:10:21.633+02:00Hi Paul!
I only know a little about op amps, so h...Hi Paul!<br /><br />I only know a little about op amps, so here's my question.<br /><br />What is the purpose of using D11,C15 and R25 in the voltage control circuit? How do you calculate the values? <br /><br />(I see that type of configuration on the current control circuit too, but I guess they are the same thing, so you won't have to explain the same thing twice.)<br /><br />Thanks.<br />Prithul.Anonymoushttps://www.blogger.com/profile/03152912334734405370noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-20889439740747351902018-04-02T16:11:10.082+02:002018-04-02T16:11:10.082+02:00thanks!thanks!Anonymoushttps://www.blogger.com/profile/13129600101663721882noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-62532502313941707652018-04-02T05:53:38.647+02:002018-04-02T05:53:38.647+02:00Fabio, here is my rationale for the 8mA bias curre...Fabio, here is my rationale for the 8mA bias current setting. The hFE (DC current gain) for the TIP142 has a minimum of 1,000. So to provide a 3A Collector-Emmiter current, it needs 3/1,000=3mA Base current. Using two transistors does not really change that, because each transistor will now only need to conduct 1.5A, so now a base current of 1.5mA is required. The total is still 3mA, well below the 8mA bias supply that is provided.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-80156310678544027672018-03-31T16:18:29.071+02:002018-03-31T16:18:29.071+02:00Hi Fabio,
You could, but you don't need to. I&...Hi Fabio,<br />You could, but you don't need to. I'm using the described circuit version with the two TIP142's, and that has been working fine.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-28230372020932068122018-03-31T14:02:30.384+02:002018-03-31T14:02:30.384+02:00hi paul, i wanted to know if we need to increase t...hi paul, i wanted to know if we need to increase the bias current for the 2 output transistors version. thanks and nice projectAnonymoushttps://www.blogger.com/profile/13129600101663721882noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-24768112965006373872017-09-20T11:16:50.569+02:002017-09-20T11:16:50.569+02:00Those are the two connections to the thermistor.Those are the two connections to the thermistor.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-1238774446651405872017-09-18T11:25:04.967+02:002017-09-18T11:25:04.967+02:00I also have a one question more at panel meter and...I also have a one question more at panel meter and fan controller schematic. There is a terminal call NTC-2 (J16), what is meaning of V- TC648? what is the pin number of tc648 of V-? and also NTC-2? Thank you sirAnonymoushttps://www.blogger.com/profile/13369331305069245182noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-39931850185749253282017-09-17T12:23:15.712+02:002017-09-17T12:23:15.712+02:00after i reading carefully at the schematic now i&#...after i reading carefully at the schematic now i'm understand how to adjust that schematic for limit current at 3A. i have 1 question sir, can i using 18-0-18 3A toroid transformer to replacing 15-0-15 3A transformer?and the last question is what type of that transformer?step down or step up?once again thankyou sir. Anonymoushttps://www.blogger.com/profile/13369331305069245182noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-72297538356557467382017-09-16T10:00:10.051+02:002017-09-16T10:00:10.051+02:00dear sir, may i ask one thing, there is a schemati...dear sir, may i ask one thing, there is a schematic to controlling voltage and current, it is only for 0..30v 0..1.5A?can i use it to controlling 0..30v 0..3.3A? thank you for the reply sir.Anonymoushttps://www.blogger.com/profile/13369331305069245182noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-62470335957801125012017-08-08T12:27:28.165+02:002017-08-08T12:27:28.165+02:00That single throw switch is used to disable the ou...That single throw switch is used to disable the output of the supply. One end of the switch is connected to -5V to be able to pull the bias away from the TIP142.<br />D19 and D27 are for reverse polarity protection. They can be normal diodes, and can be Schottky types. They need to be able to withstand several Amps, and because Schottkey have a lower drop (0.3V instead of 0.6V), they can handle more power in the same package. I prefer those. I'm working on the final touches of my design and will be able to update soon. Stay tuned...paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-14424190901698363152017-08-08T12:15:14.088+02:002017-08-08T12:15:14.088+02:00hi paul
the small circuit named Disable Output tha...hi paul<br />the small circuit named Disable Output that is connected to -5V is that connected to the on/off switch of the psu or does it go to a different switch<br />also D19 and D27 near the output is that schottky diodes<br />this is on the main circuit drawing<br />marshttps://www.blogger.com/profile/03319596788243961163noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-73527656069538266852017-08-02T08:13:26.167+02:002017-08-02T08:13:26.167+02:00thanks for the reply
guess the eyes are not what t...thanks for the reply<br />guess the eyes are not what they used to be<br />hope you have good results after you test the pcb as this project is quite interesting marshttps://www.blogger.com/profile/03319596788243961163noreply@blogger.comtag:blogger.com,1999:blog-7057630065429233264.post-87444343241643338492017-08-01T20:21:07.453+02:002017-08-01T20:21:07.453+02:00mars, I realize that I need to redo the schematic ...mars, I realize that I need to redo the schematic and segment the parts to make it easier to see. That will be done after I have verified the PCB layout. This will take a week or so.<br /><br />The explanation for the power off glitch protection is in part-1.paulvhttps://www.blogger.com/profile/11421488581167758443noreply@blogger.com