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460 Threads found on Voltage Smps
The schematic in post #1 has wrong polarity of coil, diode and output capacitor for the channels intended to give negative voltage.
I see that you decided to build your own discrete smps controller. Which is supplied by a 4 volt regulator. Which means that at M1's gate, you'll have a driving voltage of about 3 volts.....Will M1 be fully enhanced with such a low gate drive? Also, you don't mention switching frequency. But if you are switching above 100 Khz, X17's slew rate of
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
Do as per FlapJack. We measure noise with 50 ohms system. Oscilloscope : 50 Ohms input, DC coupled, Offset adjusted. lower voltage/division capacity like 2mV or 3mV/div, try with 20 Mhz BW limit for better performance., Cable : RG174 cable(rf174-04sp3-04sp3-2000 these cables are avbl fom samtec) has very small core, useful in soldering directly acr
Maybe there is a problem on the feedback line( at the low voltage between optoccupier and tl431
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
Is it asking too much to demand a complete specification, including an input voltage range? Either if the output current is 100 or 600 A, you would always prefer a multi-phase converter instead of a single-phase switcher with all switch transistors connected in parallel.
you shoudl use a current regulated smps...then change to voltage regulated control when the voltage gets to about 13.8v. ..but actually its a four stage process. 1....trickle it up 2....big current in 3....Maintain at voltage 13.8V till current dies down to v small 4...maintain at the flow voltage
Most audio amps do not have a regulated power supply voltage. They simply use a large enough mains transformer, rectifiers and a large filter capacitor. The DC voltage normally rises a little when the amplifier plays quietly or idles then drops a little at full output power. The little voltage fluctuations are ignored by the circuit.
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?
I was common for old smps designs to require 5% minimum preload to get 0.1% load regulation error. your design seems to be lacking the dynamic range on current & voltage error sense to maintain low errorwith no load.
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
The effective gate charge that must be delivered by the gate transformer will considerably increase when the supply voltage is turned on. In addition, transformer inter-winding capacitance can have an effect. The first (no supply) waveform already suggests that the driver circuit is much too weak. It takes several microseconds to charge the gate
Yes you can simulate that to demo the point. Those diodes aren?t necessarily only for parallel smps, they can be used with a single smps. Its just that when an smps goes into no-load, its error amplifier tends to rail low?..the error voltage just plummets all the way down to the rail?..this is a problem when it is (...)
Presumedly the smps won't run with 24 V bus voltage, a typical wide range circuit has an undervoltage lockout threshold of 80 - 100 V. It may be possible to perform some functional tests with lower input voltage, bypassing the UVLO and startup circuit. But only at small fraction of rated output. Standard equipment for (...)
As a general rule switching power supplies have the - terminal referenced to earth ground. That's definitely not true for general purpose smps. The maximum output common mode voltage against PE is of course restricted, but surely no problem for 2 x 24V series connection. For the linked Astrodyne smps output isolation strength is e.g
You must find out why your hydro electric is upsetting the smpss. Is the voltage wrong or the frequency wrong. I have come across industrial size (250kW) maintained supplies which do not recognise the incoming mains if its more then 1% off frequency. Frank
Here is how smps controls its output voltage (this is in current mode control). Download free ltspice and run this, and you see the regulation components in the flesh. Ok it?s a flyback converter but the feedback circuitry is generally the same for the boost
you don't need "bleeder" ..voltage is too low at output to be dangerous, in any case, the leakage current of the electrolytics will bleed it down, - - - Updated - - - Hello, That?s a lot of secondaries that you?ve got there, and are you sure that the ee25 bobbin is actually deep enough to be able to ta
whatever value keeps the voltage at the mid point within say 1% of the nominal. Also, ensure no overly high ripple current in them.
firs of all do you think it's okay to feed two transformers from a single two switch half bridge ? given that the mosfets or IGBT's are powerful enough for the job? i could increase the startup capacitor on the SG3525, though even with this one the starting up is slow enough for me to see the voltage rise gradually over a sec or two on a simple
I am a beginning electronics hobbyist and I have never designed electronics. However, I'm somewhat familiar with power electronics from my work. I tell this that you can put my writing to proper context. Thanks, when I worked at an amplifier company, everybody was going on about igbts that can replace mofets, in 300w+ smps,
Reminds me of the adapters that come with a Universal Laptop charger coaxial plugs with a multi-wire interface. One of the wires to the smps charger was voltage sense and Gnd sense to regulate voltage at point of entry for loss in the wires.(remote sense) I modified the cable so I could adjust the output of the 19.2V 65W supply with pot, (...)
Hi, I can't believe.. What voltage rating are the bulbs? Klaus
To eliminate saturation laminate steel caused by sag in voltage or unexpected dropouts, there are solutions for large power transformers but not generally tiny ones. DC and low frequency, magnetic devices are current-controlled. At the smps switching frequency, they are voltage driven. Core limitations -saturation and losses -put (...)