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473 Threads found on Voltage Smps
I'm in the process of designing and building an offline high power smps with constant current/voltage, to be specific it is going to be a 400KHz TL494 based half bridge with a 200-240VAC max 7,85A input and 50V max 20A output. I'm doing this with the hopes of eventually adding microcontroller based digital control to it to finely set the output vol
I have done my research, I always see regulation is done by varying duty cycles...But still could not get to understand fully how the smps power supply regulates the voltage. As an example, how the smps regulates 12Vdc output from high voltage DC at primary side...Really appreciate someone helps....thanks a lot.
Pages 8 and 12 of the FAN6300A datasheet explain that the primary peak current limit of the FAN6300A flyback controller reduces as the primary DC bus voltage increases. This is said to be done by the FAN6300A sensing the auxiliary coil voltage (via a potential divider) when the FET is ON. However, we had a Flyback (smps) power supply (...)
Hi, For the varistor, it needs to be selected to have a trigger voltage above the required load/smps voltage and at or below the required clamping voltage, the current ratings are usually higher than 250mA. Try browsing t
You could do one of the last two options to get the same filtering effect as with one 400V 22 uF capacitor. In the last two options, the capacitor voltage rating is 200 V each. The resistors over the caps just balance the voltage equally over each capacitor.
My guess would be that it uses an SG3525 (or similar PWM chip) and drives 2 MOSFETs in push-pull configuration. So the transformer would be center-tapped on the low voltage side. The high voltage side has the voltages marked on the board. Hard to tell if it has feedback or not without seeing if there are components on the under side of the (...)
Hello, The attached is the mains input voltage and current waveforms of a 67W, Offline Flyback converter that has no big smoothing capacitor after its mains rectifier. The flyback operates in constant off time mode. As you can see the power factor is overall better than an offline smps using a big smoothing capacitor after the mains rectifier. I
Hi I am designing a smps 500W for Lead Acid Battery Charging. I am referring Figure 16 here. I want to build this circuit (Figure 16 above link). Battery will be 12V 100Ah to 200Ah and so the charging currents will be 10A to 20A and hence the smps should be able to provide 30A.
Hi, i am planning to make a adjustable voltage smps but there are a few questions i wanted to ask. smps has 0-50V and 0-5A output and i would like to use half bridge topology. PWM IC is UC3846. The first question is that how to find the proper output inductor value and according to textbook of "Switch-Mode Power Supplies Spice Simulations (...)
There are good reasons why any three-phase power supply on the market doesn't use neutral... Otherwise you need to measure phase-to-neutral voltage and define an acceptance window.
I had designed a power supply using PI expert.I designed the same using the PI expert tool for 5V, 0.8 A configuration. I have attached the Schematic from PI expert, Eagle Schematic of the same, PCB design. Only difference in circuit made is the ceramic capacitor attached to BP/M pin is 0.1uf instead of 10uf I got the output as 5V at No L
Hello, I have designed an smps with dual outputs of 5Vdc and 12Vdc and i have to prepare a datasheet for that smps. For that, i need to specify one parameter for minimum and maximum AC input voltage by which smps can function and give correct outputs. i have tested maximum input voltage of 440Vac (...)
Hi I designed device which is supplied by 5V provided by ACT4060 (smps regulator). Regulator produces stable 5V but only when there is no load connected. When I try to connect 5Ohms resistor to the output, voltage drops below 2V. I use 22uH inductor and 22uF ceramic resistor. When I tried to replace inductor to 10uH It was a little bit better
The schematic in post #1 has wrong polarity of coil, diode and output capacitor for the channels intended to give negative voltage.
Hi, Having problems with load regulation of SEPIC. It's on a breadboard, but doubt that is the cause of the problem, may be compensation, or other, looking for tips to troubleshoot, and ask question/help about compensation, as I'm finding parts of that very hard to understand. Line regulation appears acceptable, for +4.8V/+5.5V/+8.5V in outp
Hi I want to design smps with LCC topology with the below specification Vin=650 volts Vout=1000 volts Iout = 20 amp frequency=50 khz output ripple voltage=1 volts I want to calculate the capacitance of output capacitor. I know the below formula: C = / Vr C in Farad I in Ampere f in Hz Vr in Volts
If you have a (more or less) constant load, you can make a simple linear power supply. If you want to avoid a bulky transformer, go for a smps design. If you want a tight regulation of the voltage, you need to consider a regulated supply.
Dear All, I want design smps with battery back up for long time. But my charging current is very low approx. 2Amp but i want to increase it. I want design the system with following specifications: Output voltage : 12-15VDC Load current : 4Amp. Battery charging current : 6Amp. With overload protection Can anybody help me?
Hi, Your description is not clear. * what is your input voltage range? * what is your output voltage (range)? * what is your (output) current (range)? Generally: I_in = I_out * U_out / ( U_in * efficiency) Klaus
Hello, We are scoping the output voltage of a 100W (1V5, 65A output) , 3MHz Vicor VTM48? power module with a Scope Probe PCB Adapter (as in attached JPEG) soldered into the PCB. This is essential since the 3MHz VTM48 module cannot be scoped with the scope probe with its ground 'tail' clip, -because there?s too much noise like that. However
Hi gents I need your help in one smps problem It is rectifier module supply 48V/50A for telecom equipment and the issue as below: when I powered on the smps there is a 48V for seconds then output decreases gradually till reach Zero. I isolate the switching transformer and run the voltage test method all the primary volts are OK and (...)
I was trying to make a circuit of DC voltage booster131983 It showa a maximum current of 400 milli amp going through the collector of bd136 while in reality it should have gone to Killo Amperes considering that inductor series resistance in proteus is just 0.00002 ohms
?surely the above thread is incorrect?..smps output ripple should best be measured with a x10 scope probe, and not a piece of coaxial cable which will be a 1:1 probe and will overly capacitively load the high frequency bit of the measured value? All that is needed is to remove the ?tail? at the end of
Does the smps have an adjustable output voltage? (24V could be very high for 5V, unless your smps can output 5V.) An easy way of generating a negative voltage is to use a (cheap) charge pump, like the 7660, but this device only outputs the voltage that goes in, e.g. +5 > -5, etc. Or you could use a (...)
Your secondaries have the same number of turns (9T). Theory says they produce the same voltage. However your specs say you want three different voltages. Does the transformer have internal construction which provides this? Or did you intend to add regulation?
Hello, For the VTM48? power module, what is the tolerance on the PC pin voltage during fault? The VTM48? datasheet, on page 3 says that PC pin goes to ?2.5V? during fault. But what is the tolerance on this voltage? VTM48? power module datasheet
This concerns the attached schematic of a 48V to 1V5 smps which uses Vicor power modules. Do you agree that the Error Amplifier small signal transfer function should feature a ?divide by 24? factor? -And that this must be done so as to take into account the fact that the output voltage is sensed at the 1V5 rail rather than from the intermediate 36
if there is Mosfet boost converter I hope you understand your request. Let me explain; 1) 12v X 600A = 7200 watt output power. 2) I will sincerely doubt that, unless you are employing state of the art converters, that you efficiency can be
My plan is to make a charge controller to auto charge a 12v Lead Acid battery. Here is the idea - 1. Power supply will be adjusted to deliver a safe voltage above 12 volt. Say 14v. Note that ampare rating of the power supply is 20A (safe for a 120AH battery) 2. Power supply will be connected to the battery terminals and the charging will be
Hi there I made this power supply but I haven't tested with load. I've ordered class d audio module but its not shipped yet. I need to wait 2 more weeks. I measured +-50V without load at all. Please tell me, I need to know what will be the voltage with 150W load since there are no regulation. Im wondering. :bsdetector: The sch consists of 5A
Hi, i have 15V and i would to have 5V, i dont want to do it with switching power supply because of its noises. if i do it with voltage regulator; Power Loss = (15V-5V).1A = 10W. Power lost is so much. Any ideas how can i do it? thank you best regards
Hello, We are doing a 48V to 1V5 smps using a vicor PRM48 power module feeding down to a VTM48 vicor ?electronic transformer?. (the intermediate voltage is 36V). On page 21 of the PRM48 datasheet, the output voltage of the PRM48 is shown to slowly ramp up at startup?.also, during this startup, the PRM48 output current is being held very (...)
Hello The attached schematic varies the reference voltage shown from 0V to 1v5. (In the actual circuit it will be the variable reference to the error amplifier of an smps..thus giving a soft start by slowly incrementing the reference node voltage). Do you have any ?less component count? ways of doing this? I need to keep the LT1634 (...)
Hello This smps module appears to have a settable output voltage via its ?REF? pin which enables the user to set a voltage at the error amplifier reference input. However, when "Adaptive loop? mode is set, the datasheet says not to use the ?REF? pin. Why is this? Why can we not use the REF pin to set the Vout? MPRM48NH480M250A00 (...)
This is also a kind of resistance. But when an electric current passes through it, its resistance drops. Thus the voltage drop does not occur. If you refer to it's datasheet,you will see that it is related to its resistance at 25 °(in this type 100ohm) and its size(D-9).
recently i build led board that works on 5v. and as simple i use 7805 for prototype.but what about higher amount of current? i have option for 5v-10_or_20amp smps. but i have already 12v with enough current how to regulate them?
Hi guys, I have a design that is very similar to the the one in the demo circuit as per below link With my spec being Vin-170V-350V Vout24V @1.25A No secondary sync used For some reason when I put a load of 5W the voltage is 23.7V and it regulated out the whole input
Hello, We always here how voltage rails supplying FPGA?s DSP?s and Microcontrollers should have really low ripple voltage on them -otherwise they are said to suffer corruption of their internal data and operation by noise. However, how true is this? Often, these sort of processors are supplied by an smps, which obviously has a (...)
Hello We are delivering several kW's of power to a very low voltage system (1.8V). The downstream smps is obviously an array of paralleled sync Buck converters. Due to the obviously very low duty cycle of these sync Bucks, the sync FET is ON for the majority of the time. Therefore, the efficiency of the entire system is being determined by the r
Hi Everyone, Have a great day. I am using a smps WITH min voltage of 110 V nominal voltage 230 V and Max voltage 265V. This smps having failure of TNY CAPACITOR AND RESISTOR. The Sch is attached with this ( RED marked components are failing continuously ). Pls help me to resolve this issue.
Connecting 2 smps in series at the input side has a risk associated with it, if any of the smps input power is less than other smps (imbalance in the input impedance in spite of connecting secondary in series due to mismatched efficiency), that smps will get subjected to a higher voltage on its input. Also (...)
Hello, We are designing a 20W smps which simply supplies 15V at 1A to an RF Phased array antenna circuit. (its for comms). Vin = 48V. We were wondering if it is overly extravagant to do this as an Half-Bridge LLC converter? Its just that the smps will be very close to the Comms signal processors and other sensitive circuitry, so we wondered sh
Hey Can anyone suggest me how to improve this PCB layout? The transformer is 12V and logic side is working at around 200kHz. The power side is at mains voltage and also works at around 200kHz. The two MOSFETs will be placed on heatsink. Please take a look: obrazki.elektr
Hello, The attached is two smps?s in parallel. They both feed into the same output which is voltage regulated. There is a single error amplifier which feeds the two controllers (one for each smps). There is a micro which senses the current supplied by each of the paralleled stages and then makes adjustments to each stage in order to (...)
I cant see any feedback in your circuit. Also, I am sure you know the 1u blocker cap Is only for voltage mode. (have you set the sg3525 up for voltage mode?) The resonance frequency of the 1uF and the transformer leakage must be well lower than the switching frequency. - - - Updated - - - I believe you shoul
Here is a 5Vout 7A current mode, ccm flyback. It runs off the DC bus after the mains rectifier, and since you indicate 220VAC mains, I made it for 195vac to 265vac The duty cycle at min vin has been made small so that there is a decent length of secondary conduction time to make irms sec small. But the duty cycle was not made so small that th
I have a 12V smps which I believe I can set it to output 5V with a in-built pot. Will it be best idea to do that ? or should I set it to output more voltage like 9V and use a voltage regulator ? Because it needs to run microcontroller and other logic ICs and few amps load. The reason I'm asking is there any condition in which (...)
Getting 6V with no load suggests a defective circuit, or a switcher that can't work without a load. Check in datasheet & application note. If the circuit maintains 5V above a certain load current , it's probably the second case. The "24V" node is half-regulated and won't meet an exact output voltage without additional post regulator. Either stay
Use TL431 or similar secondary voltage regulator instead of Z-diode.
Hello, Here is two identical Full Bridge smps simulations in the free LTspice one has leakage inductance in the transformer, the other has perfect coupling (no leakage inductance). Notice how the one with leakage inductance has far less severe reverse recovery of the secondary diode. (attached are waveforms of secondary diode voltage (green) and