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54 Threads found on Switched Mode Power Supply
I will use the SCR like a diode between the capacitors and the load. Sounds erroneous. A SCR can't switch-off DC current, at least not without a second commutating switch. The problem of instantaneous current limiting refers to inherent limitations of a switched mode power supply in achieving current and voltage (...)
Maybe you calculated the duty cycle values wrong or didn't consider real circuit parameters. switched mode voltage converters should be controlled by feedback control rather than using pre-calculated duty cycles. To make us understand the specific problem, you should give circuit details and parameters.
Are you asking us for help to read the specification of your instrument? It's specified with < 1.5 ms "response time" (10/90% rise time). Technically, it's a switched mode power supply with recuperation, so it surely involves output inductors and filter capacitors. If you want considerable faster rise/fall time, use a (...)
There are different operation principles of switched mode power supplies with transformer, particularly forward and flyback converter. To describe it a bit simplified, a forward converter works similar to a low frequency transformer power supply, the output to input voltage ratio is primarly defined by (...)
Hello Nimeng. I don´t want to discourage but design a switched mode power supply is a very challenging task, i.e. to obtain a good design. Your intention to modify your power supply also I don´t think is a good idea. It is not just to change some components. With the information you (...)
Hi There, I need to say first that my electronic experience is very minimal! I have a PCB from an arcade machine power supply, the whole power supply had around 4 PCBs in total and I traced the fault to this PCB. This PCB takes 120V input and (i think) outputs 5V (I measured the 120V, and the wire terminal has a small (...)
Defective RC receiver IC, defective power supply causing strong RC receiver supply voltage ripple. Strong optical interferences from LED or FL with high switched mode supply might be also a reason.
Dear Experts I want to learn about designing of switched mode power supply. please tell me step by step procedure of designing my own SMPS. i am beginner in SMPS, so please help me. Regards MM Khan
i have a SMPS : the ratings are: 250VA i/p . battery i/p 12V. now how do i decide battery AH? say i want to use 20W 4 CFL tubes for backup time of 1 hour.
Is It ok to feed in an 11V bias supply into the VIN pin of the LT3756 Led driver ic.?..its used in a buck led driver with 48V = vin, so the ISP pin sees 48V. Just checking its should be as it can do boost operation, and in that case, the VIN pin is definitely less than the ISP pin in voltage level
Hello every one on board . I am right now trying to analyse a power supply as an assignement from a teacher , he gave me a computer power supply of a switched mode type . So after checking the primary side , i can see that it is doing its job with a correct 300 V dc on the main (...)
This is to make the power supply safe to work on. A 100 MF capacitor charged to 400V - typically found in the front end of switched mode power supplies, is lethal. Frank
Hello! I would like to use a high discharge rate Li-Ion Cell (3.7V) and design an adjustable power supply, my requirements are: 1-10V output voltage. If possible up to 10A. (i realise that may not be possible when my output is high voltage) Load resistance from 0.2 or 0.5Ω up to 3Ω. Smallest possible size since it's portable. I
A very common type of power supply is called a switched mode power supply (SMPS). If you wanted a mains to 28V power supply from the 230V mains,the input circuit would rectify your incoming AC, this would give, 230 X 1.4 ~ 325V DC. A high frequency switching (...)
Hi, At present, I am learning about switched-mode power supply and Low drop out regulator using CMOS. Could anyone suggest some good books about this? The main problem here is "using CMOS". Thanks.
So I want to try to increase the max current through LM317 in attempt to decrease the heat. Should work how? power dissipation is voltage drop multiply load current, about 6W in your case. Won't work without a heatsink. Alternatively, you might think about a switched mode power supply, which has (...)
hi friends......... I wanna make switched mode 15 V 6Amp power supply for my project. please suggest me which is best and cheapest topology and circuit diagram for that power supply.. please help me...... thanks...
Hi! If you are interested in power electronics you can make a switched mode power supply based on TL494. 79901 You can find some workable examples with explanation in book-George Chryssis “High Frequency Switching power Supplies.” Hope it helps.
The cheap power supplies on sale are switched mode, so the transformers and inductors are 5% of the size//weight of the 50 HZ versions. The voltage overswing on the inductor is something we had problems with on a 20 KV, 5A supply, we put VDRs across the inductor and a 10 KV spark gap. You could try putting a chain of diodes (...)
Use some kind of switched-mode power supply like these:
Depends on the power supply concept. If you are using switched mode voltage regulators or linear voltage regulators for supply nodes with low current consumption, a single secondary could work for the application.
Im working on mini pro..for which i selectd SMPS(with feedback).OP is designd for 12v dc,500mA. . But im not getting the OP...i dont know exactly why?i was wondering how this crkt starts working initially without any feebak...
Hi I have also one question to you. Can I joint this two circuits (A3942 and afraid of damage or oscillation? It is connection between switched supply and solenoids driver. Load in one branch is 60ohm resistor and cca 10mH inductance. Requirement of output is 24V and 400mA max. What is gene
hi i have a lot of electronic items that uses the bulky heavy transformer based adapters ,, can i replace them with lighter switched mode regulated adapters? e.g my current adapter is labelled 12v , 1 amps,, and the new one is 12 volts 1.3 amps? thanks
Appliances with wide supply range are mostly powered by SMPS (switched mode power supplies) in flyback mode, that can easily span the range. Automated switching with relays or triacs/solid state relays can be found in rare cases.
I would filter out the highs then rectify them and use a small capacitor filter, so as the highs increase there is more DC. Try to use the DC to move your bass speaker cone. It should work but it will only move the cone in one direction. I think you must use a fast rectifier, like used in a switched mode power supply. Frank
See "Linear regulated power supply" and "switched-mode power supply" sections in this article: power supply - Wikipedia, the free encyclopedia .
In empirical control loop optimization, nearly everything is possible and has been tried at times, I think. Lead-lag compensation, that you apparently intend, is a very common means, however. It's often applied e.g. with switched mode power supply controllers.
Has anyone made a switched mode power supply to power a ~50 Watt valve amp? Would need about 400 volts output at a couple of hundred milliamps. There was a silicon chip article on modifying a pc power supply for valve amps, but I can't find it. Peavey have just (...)
You're free to design charge pump (switched capacitor) converters at any current level. The question is, what approximately means for you? A witchd capacitor converter als well as e.g. a push-pull forward converter can provide approximately 1:1 conversion, but with some internal resistance. To avoid any load dependant voltage drop, a conver
Due to power supply restrains, I have to raise the input voltage level (DC) to power a PA that's gonna be working in the UHF range. What precautions should I look into before attempting this, such as maybe harmonics, some special kind of filter at the output, separated grounds, or stuff like that? I know some of the theory, but don't have (...)
Hi Can any one help me in designing a switched mode power supply (SMPS). I want to convert the mains 230V (AC) to 3.6V 2A (DC). I want the design to be as small as possible, so any recommendations for a very small PCB mountable transformers that can handle 2A will be great and also if it is possible a circuit diagram for (...)
switched mode power supply with a high frequency transformer is the only feasible way.
Hello, I'm a hardware design engineer with specialization on power supply both switched mode and linear application, high wattage or low wattage. I think we can help you in your designs. email: pcb1001(at)gmail(dot)com Krgrds, Kris
I've read some PWM's application notes, I think there are commercial transformers that you can use. There's a huge market in SMPS's, do you think that transformer manufacturers would just sit and wait for us to request them for custom ones? Do you know the book "practical switched mode power supply design" by Marty Brown?
i need to design switched mode power supply 5volt and 5A
Average power is more meaningful. Suggest you connect load, then measure voltage across it. You will probably find it drops a fair bit. Sounds like what you are doing is not going to be that voltage critical anyway. If you need exact 12v You could always buy a plug in switched mode supply, they are pretty cheap these days
Hi all, my TNT decoder do not run!!! I verify power supply, but I'm not specialist of switched mode power supply. In connector I found : 3,4V, 5V, 12V, 32V but in the out 23V (22V) i found 0V! that all for the moment. I need help to repair my decoder I search schematic or all (...)
Hello i am doing switched battery charger with UC3909 Datasheet: on page 8, fig 3 , it shows the circuit diagram i have 2 qu's... 1. Why do they use an auxiliary coil to supply the UC3909. -Surely they should just power the UC3909 from the secondary coil that connects to the battery?
As your input voltage is DC (continuous) and not AC (alternate) you should consider to design a switched mode power supply: i.e. transform the DC input voltage into an AC voltage, apply it on a transformer with several taps and rectify, filter and regulate the output voltages. See an example:
Working with PICmicros is not that difficult, as they are designed to work in several ways of power supply and source of clock. Beginning by the power supply, PICs can be powered by batteries or by power supplies (linear or switched mode). The most common (...)
Hi everybody, I want to design a high speed transformer, what are the characteristic to consider, inductance, wire size ... I have difficulty to understand the mutual inductance, how do I calculate it ??? My transformer is for switched mode power supply so it will will run higher than 30 kHz I need to step down from (...)
Hi fernando Try this at All documentation is provided at left side menu in the page. Pay attention: i think that exist a bug in electronics now article. See the schematic of power supply (hand draw schematic), its corrected version. If a switched mode is ok : h++p://www.elecf
What is your power supply ? This is an important question. power LEDs have a forward voltage between 2.5V and 4.5V (see datasheet). This means that they need a supply voltage about 10V..18V in series. So your supply voltage for the LEDs must be approx. 20V (worst case). To keep the (...)
I you don't have access to a switched power supply you can use a Standard power supply Design with some extra components, like power transistors.
Generally, the main hightlights of a Schottky diode are faster switched time, lower voltage drop. The drawbacks are higher reverse leakage current, lower reverse broken voltage. In switched mode power supply applications, Schottky diode if often used in case of low voltage high current. Besides, A (...)
Hello guys, currently i'm working on a DC 12V to AC 230V switched mode power supply using SG3525. I noticed that most of the output of the reference SMPS circuits that I found are not pure sine wave. Do u guys have any good circuits to share? Besides that, the transformer is giving me some headache. I plan to custom build (...)
If somebody has a 12V/40A(minimum) power supply schematic(not switched mode), for car amplifiers, please post in the forum, or contact me. Thanks
Assalam O Alekum ! Can anyone tell me about switched Regulated power supply Any documents will also be appreciated Thankx