https://community.element14.com/technologies/power-management/element14's Power & Energy group is where an engineer or a maker can learn about AC/DC power, DC/DC converters, switching regulators, LDOs, ultra-low power, energy harvesting, energy storage, supercapacitors, and power management ICs.en-USTelligent Community 12https://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235937Tue, 02 Jun 2026 22:40:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:ee221758-dde9-4d56-8e04-3ef2f4fdbfa1colporteurYeah that ain't going to work. The indicator diodes are reversed. Working the schematic in KiCAD and found the oops.https://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235923Mon, 01 Jun 2026 16:22:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a56fea43-6656-4ff9-b172-328ec2572faecolporteurAt one point in my electronics lifecycle I could do those goes-into calculations. Now I use resources of digi-key when I think about it. You mention 1.5A. I need to look at the wall warts ( collection of phone chargers) I'me using. I think they are less than 0.5amps.https://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235922Mon, 01 Jun 2026 14:02:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:20395d26-056e-4c82-91c0-07a3fcfb9ce2michaelkellettIf you do a pcb for it I suggest that you add the 2 RCs across the rectifier - if they don't do any good then you don't need to fit them. Referring to your circuit above, 10uF on the input looks very small. I think the LM317 can manage 1.5A. At 50Hz you might expect to see 750V ripple (assuming a conduction time of 5ms). 4V ripple at 1.5 A sounds more reasonable so C1 = 1.5 / 4 * 0.005 = 1875uF - use 2000, 2200 or maybe 1800. You can scale with current - so if the max current you will draw = 500mA then a 680uF will be fine for C1. MKhttps://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235921Mon, 01 Jun 2026 13:25:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e12ca60a-eedb-465d-98b4-f440211e4966colporteurPower supply design is an electronics art on itself. The supplies found in rack servers blow me away. A little overkill for a simple Arduino project. I've just started chapter 9 in the book you mentioned. It has contributed to this redesign motivation. My son-in-law pokes fun at me because the book is my go to bathroom reading material. I included the protection diode ideas from the second drawing in my upgrade. I found an LM317 circuit drawing that holds some promise. Changing two resistor to get a different O/P voltage. This redesign is to create the ubiquitous P.S. for projects. I can't recall the last time I used an O/P other than 5V. It would be nice to have a 3.3V option. Maybe this circuit with the protection diodes from your second drawing is an option. Humm wonder how it layouts on a PCB?https://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235915Mon, 01 Jun 2026 08:23:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:c134b929-42d7-4b09-870f-97eac6fc94abmichaelkellettWhat you put in a power supply must surely depend on the specification. Input voltage range Output voltage (range if adjustable) Output current Input transient protection Output over-voltage protection Noise Max inrush current Efficiency Cost and many others. I very often end up with an LD1117 in a SOT223 package and aluminium electrolytic caps on input and output but quite recently I did this: It's a 5V internal supply which is part of a much more complex power supply. It can get input power from three different sources. When running from super-caps it needs very low current drain and may need to work with an input as low as 6V and up to 30V, from the external PSU it may get anything from 24 to 48V and from POE anything from 24 - 70V with 80V surges) I couldn't find a switcher that could do everything including the 80V input so I had to use the Q11 pre-regulator on that power source. A more general purpose tip that I can offer is that when you are using a mains supply with a transformer, bridge rectifier and big capacitor followed by a ciruit like your standard one then a common source of noise is ringing where the transformer inductance interacts with the rectifier diodes switching. An easy fix is to put snubber caps across the rectifier. (See Art of Electronics 3, The X chapters, chapter 9x.6 page 410) I try to remember this whenever I design a mains powered supply. This PSU was designed to power some current sense buffer amplifiers which needed an isolated low noise supply. MKhttps://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideas/235914Mon, 01 Jun 2026 04:22:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:ce744283-47af-4486-acbb-5b24581767d0ralphjyYou need to flip the LEDs over in your schematic so they are forward biased.https://community.element14.com/technologies/power-management/f/forum/57002/what-s-in-a-power-supply-your-design-ideasSun, 31 May 2026 20:42:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:40d6aa9e-d26d-42ca-8863-4b6837d11614colporteurWhat do you include in your power supply design? For years, I use a LM7805 regulator with an input and output capacitor as my simple 5V power supply on PCB's. (top drawing) Itypically plug in a 12VDC wall wart as a source. I use the same 12V to feed the Arduino. No AC design needed. I discovered after my Spring Clean project, it would be nice to have power supply indicators. I seem to recall Shabaz had some nifty things he did with zenor diodes on power supplies. Great protection, little cost. I can't find my notes on that idea. A search for power supplies in the community I came across this. An isolated low noise +/-5V DC power supply From the post I added the indicators and the protection diodes to mine. (bottom drawing) I've seen designs with an LM317 regulator, looks cool. I have a bag of LM7805 components I have to use up so regulator changes are not a high priority. I find it hard to walk away from components that are bought and sitting on the shelf. I recalled when I worked in Engineering during the 80's, new Electrical Engineers assigned to a project would always start trying to improve the power supply. Our derogatory comment, there is a new power supply born for every Engineering graduate. As an Engineering Technologist I never understood why you would design something you could buy off the shelf. For a few buck you can get a DC to DC power supply with indicators and other bells and whistles. Why build your own. I just like a 5V supply on my designs. My goal is to enhance my current power supply design with some bells and whistles. Identify the parts and then perfect a PCB layout I can replicate in the future. My first step in any KiCAD project is copy the power supply. With that done I can start step 2. If you have insight to share that would be great. If you have a KiCAD drawing to share that is even greater. I'm no above begging to get ahead.power supply circuitpower supplyhttps://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235777Sat, 23 May 2026 09:01:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e963deb9-94d7-4f8e-bbd7-2b6908dcdfb2beacon_daveSounds familiar... USB to Banana Plug Adapter https://community.element14.com/products/pcbprototyping/b/pcb-blogs/posts/usb-to-banana-plug-adapterhttps://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235771Sat, 23 May 2026 07:01:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:bbe2e335-2cc0-4da4-8062-0b8519145831dougwIt is handy to have a USB connector that can supply USB voltage and display how much current the load is consuming.https://community.element14.com/technologies/power-management/b/blog/posts/researchers-develop-water-battery-that-can-be-safely-disposedThu, 21 May 2026 19:25:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:0192b74b-1b7d-472a-924f-f110c92b4f8dCatwellComparing the neutral pH 7 with other battery technologies. (Image Credit: nature ) Researchers at the City University of Hong Kong have developed an aqueous battery with a pH 7 electrolyte. The battery system is built with water-based materials and can be used for long-term performance. It can also be disposed of it in the environment without special recycling equipment, making it safer than batteries with toxic chemicals. The team built the battery with covalent organic polymer (COP)-based electrode materials. More specifically, it uses a hexaketone-tetraaminodibenzo-p-dioxide COP as the main electrode. This organic polymer is paired with a water-based electrolyte containing magnesium (Mg2+) and calcium (Ca2+) ions. By integrating and using a neutral aqueous electrolyte, the battery system is less likely to be subject to corrosion and instability that occurs in alkaline or acidic batteries. The water battery works by reversing ion movement inside the aqueous electrolyte. While it’s running, both the Mg 2+ and Ca 2+ ions move between the polymer electrodes. By transferring ions this way, a charge balance forms in the battery, enabling an external circuit to drive electron flow that produces electricity. Water-based electrolytes help ensure seamless ion transport while limiting side reactions to make the system more stable. To analyze the electrode structure’s performance, the researchers created three COP-based battery systems: Hex-TAPZ-COP, Hex-DABZ-COP, and Hex-TADD-COP. They tested all three designs under the same pH 7 aqueous electrolyte conditions, comparing electrochemical stability and energy storage. After testing, the Hex-TADD-COP version came out on top. Electrochemical performance of the Hex-TADD-COP negative electrode. (Image Credit: nature ) During experiments, the team showed that the Hex-TADD-COP battery has a cell voltage of roughly 2.2V. Additionally, the system can deliver a capacity of 112.8 mAh g -1 and an energy density of 48.3 Wh kg -1 . Although the system isn’t designed to compete with high-energy lithium-ion batteries, it’s still practical for low-power applications. More notably, the battery has a high-performance cycling stability, lasting 120,000 charge-discharge cycles without degrading. The paper also says the battery performs well at high current densities that reach up to 20 A g -1 . That suggests it can withstand rapid charge-discharge conditions without sacrificing performance. Have a story tip? Message me here at element14.researchalternative_energybetteryon_campusuniversityuniversity of hong kongpowerenergyhttps://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235709Thu, 21 May 2026 10:32:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:1f67d3e4-d916-4a5e-a4b2-9298fc863818geraldsPlease read michaelkellett 's information and arguments again carefully. I agree with him; I think similarly. BUT --- What is YOUR wish? You haven't answered any of the questions so far. The real point is: what do you need for yourself? The thoughts and wishes of others are rather irrelevant. You have to choose what's right for YOU, what functions it should have, and then you have to calculate YOUR costs accordingly. ..."" ""...feel free to go nuts, any help is greatly appreciated! ..."https://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235704Thu, 21 May 2026 09:09:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:688e3815-da8f-4d79-8a5c-39ea15ebe396michaelkellettAs is common with questions such as yours I find that replies (including mine) focus on the current project. One of my current projects is a switching supply for precision motor control - its a buck regulator designed for very high efficiency and fast dynamic control of the output voltage. It works with anything from 10 - 60V input and may draw up to 10A from its supply, it is capable of 8.5 to 60V outputs at 6A (8A for short periods). The efficiency is between 90 and 96% for any combination of input and load above 0.5A. It has built in pull down for fast output voltage change with low or zero load. Now you can see the form of my PSU requirement - currently I'm using the AimTTi MX180 for the supply but it cant provide enough current at 60V. I'm using a Rigol DL3031A electronic load and a Keysight DAQ970A for data acquisition with a custom interconnecting box for current measurement. It's all controlled by a PC via Ethernet. If I want to test at full input power I have to use a brute of a supply which has only manual or analogue control and can do 100V @ 28A. I want a load which can simulate a motor type load and feed power back into the supply. A typical source meter can do all this but only at low power. Analogue modulation allows you to connect an existing programmable waveform generator. A built in one would be fine but all to often these are poor second cousins to a decent signal generator. (You need triggering, slew rate control etc). A single box solution to this problem would great, but unlikely. I think Keysight can do it (just about) with multiple boxes but very expensive. So in the end I'll do the motor load testing with a motor ! Could you explain you project a little - is it commerical, marketing, fun or something else. MKhttps://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235703Thu, 21 May 2026 08:24:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:30a04e63-3d31-4095-8d67-4b2fcc716a30MagnethiccWhat do you like about the E36313A that you can't find in other bench power supplies? What does it miss? Thank you.https://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235701Thu, 21 May 2026 08:01:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:df57360f-8bf1-47d2-8b87-b39f3aa035b1MagnethiccI do not know how you came to the conclusion that I am not knowledgeable about electronicshttps://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235700Thu, 21 May 2026 07:59:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:06503c91-e8c6-4de3-b105-dfdff72a2835MagnethiccThank you Doug. What do you mean by USB output that can monitor or limit current? can you please elaborate?https://community.element14.com/technologies/power-management/f/forum/56962/triple-output-bench-top-power-supply---any-requests/235699Thu, 21 May 2026 07:58:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:b5c0e00b-fa8b-49cf-8a49-9aa28e5d818dMagnethiccThank you so much! a few questions: 1. why would you want the analog modulation? 2. would a 200W source, 20W sink will be good enough as a 2 quadrant or 20W is too little? 3. Would you wish for an arbitrary waveform generator? if Yes what kind of specs would be necessary (what bandwidth for example?)