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382 Threads found on Voltage Smps
Full Bridge smps primary DC blocking capacitor...(capacitor in series with primary) Does any reader know of a book that explains ...... 1. Whather or not this capacitor is needed in voltage mode control? 2. Whether or not this capacitor is needed in Current mode control? 3. Whether or not this capacitor is needed in Current mode control
it means that you have an smps where as soon as the inductor current falls to zero, the driving voltage is again forced across the inductor and the inductor current begins to build up again. So the inductor current falls to zero , but does not languish other words, the inductor current is triangular and not trapezoidal, and there are n
Hello, This concerns the use of high side fet drives in smps?. On page 25 of the LTC3722 datasheet (bottom RHS), it says that bootstrap high side drive ic?s such as LTC4440 can be used when input voltage is less than implies that if above 80v, gate drive transformers are needed instead. Why do they say this?, bootstrap high side d
I could not find the proper spec sheet for transformer which determine the power or voltage current rating of transformer. I also could not find the turns ratio. If u know the cross sectional area of input and output coils with their length, the resistance of coils can be found. Using these values u can determine the VA rating and with power factor
Hi all I have some stupid question about ac-dc conversion. As you already know, diode-bridge is connected to AC line and rectified voltage is go through flyback stage in case of flyback ac-dc smps. - AC Plug -> Diode bridge -> Flyback stage Then let me write a stupid question. How about below construction? - AC Plug -> transformer
Why don't yu try a Linear Adjustable Regulator just after this smps ?? You may design your smps ( for instance 85-270VAC )then you can connect a variable regulator then.. smpss work still rectified line voltage so DC.Flyback is a good choice..
i have a power supply in which driver ic is ICE3BR0665JF AND FB controlled by TL431. its a 18vdc,100w smps.i want to use it in project where i need 24v dc it suitable to use if yes how to change its output to 24.what about its performance. if any other circuit plz suggest its urgent
basically this inverter incorporates high frequency intermediate stage , however the output frequency is still 50/60 Hz, In this inverter , basicallly there are 2 stages , 1) DC-DC stage 2) DC-AC stage in first stage a lower voltage dc say 12V is converted to 311VDC now in second stage the 311VDC which is a peak value is converted into 220V
Dear Friends , I have a circuit which works as following : Mcu board : reads temperature via pt100 sensor , shows temp on lcd and it has to print the data on a thermal printer . Mcu board is working on linear power supply which powers voltage to pt100 circuit , mcu , lcd etc. The thermal printer requires 5V , 2A of current so i am using a pc
I've done googling...Majority telling only 3 important things must consider then it'll work: 1.) voltage 2.) Current 3.) Rds-on resistance Any opinions on this? Thanks. I agree with previous posts but would like to add the following concerns that ought to be checked. - If significantly lower RdsOn,
Feedback is more complicated in a boost converter than in a buck converter. One issue is that your desired Vref does not exist for the first few cycles. When you finally have your Vref, it cannot be applied directly to your control device, since it is outside the supply rails. It must be divided down. Vref (voltage regulation) is one type of feed
I want to control voltage (CV) and current (CC) using TSM103 at smps output. Please help me design calculation . I have to CV/CC at smps output having 54V and 1.4A.
hi , i have built a half bridge smps with pfc front end for 2 X 200W class - D . it works fine but the wave forms that i see is troubling me .... Can any one have a look and tell me if i am doing it wrong ..... the smps has a open voltage loop . wat is troubling me is primary waveform at 90% load the wave form should be flat during the dead (...)
If the turn ratio of the transformer is wrong and there are more turns in output coil than needed then it will produce higher voltage level in output. The feedback circuit will try to regulate it by reducing duty cycle and you will see a narrow pulse of PWM output especially when there is no load present. .
I think, the shown circuit has sufficient protection, even if the signal pins are connected first. What you can expect at the maximum is a few nF smps Y capacitor charged to the mains peak voltage which will discharge through the 6.2 k resistor. Stored energy is below 1 mJ, no problem for a 0603 resistor. The Z-diode will safely protect the MOSFET
Hi I need a inverter for a Mig/Mag machine wil wire feed, I have read this has to be a constant voltage source needed of 22/28 volts. So correct me if I wrong. the constant voltage source is a version of smps with voltage feedback to adjust voltage? wire feed speed take care of current. the Tig (...)
So I connected it between 9V 4.5A DC smps and external camera flash which requires 4xAA cells. To my surprise when flash is charging input current rises to 2.2A and voltage drops to about 2.5V. Is this normal?
I prefer the guru Keith Billings who has 50 yrs smps design experience and many books. The choke must not saturate during Ton and must have enough energy stored during Ton so the voltage does not sag during Toff. Th
I presume you used a design simulator such as WE's component selector which calculates all the losses. Since you did not provide any details on input /output voltage we cannot say for sure. e.g. Why 200kHz? why not 250k? What were your results? <150mW?
TVS will not fix your problem. Preloading your smps for 5% may reduce overshoot. Improving design Phase margin may improve it more. I think you have a measurement error as the LED current would be nonlinear and ringing would NOT be sinusoidal at this voltage >60V. ....Reason is the LED string will probably have a lower ESR than the 500W rated
I presume you have an idea about the block diagram of the inverter. To use the ferrite transformer for battery charging, you need to feed the high voltage winding of the transformer with a 50 kHz AC voltage. How do you chop the mains voltage (probably after rectifying it)?
Hi, dynamic input impedance (dVin/dIin) = -((1/D)^2) * Vout/Iout thisis for low frequency. just the power transfer characteristic of the smps. For higher frequency you have to take the input Cs into account. It is an optimized calculation, it does not take efficiency (and it´s variation with input voltage) into account.
We are advised to use any input voltage sources.
I see a lot of problems with this design from dI/dt coupling, conductive losses on traces, no short circuit :sad: withstanding p rotection, no high voltage(3kV isolation from arcing. Start over using busbars with common mode paths on opposite sides of insuator yet high voltage insulation with 1kA surge capability.
Hi guyz, i have made half Bridge 27V,26A..but output voltage is not is decreasing continuously with load current.1A decreses 1V approx. .what should be the reason behind it?.. Any help would be appreciated. Thanks in advance.
Hi all, Designed Flyback Topology based smps.Now want to convert smps in to Zero voltage Switching Flyback smps. How to design ZVS Flyback Converter? Thanks & waiting For Knowledge Enhancement,:thinker: Sachin
Hello. for design a voltage mode control compensation network of smps I need calculate forward gain (G) in 1+GH equation that H is compensation network Gain. that for forward gain we have : G = Vin * (Ns/Np) * Gm where: Ns/Np= trans ratio Gm= modulator gain suppose a half bridge smps designed to work for 175 to 280 Volt AC: 1-[
Hello Again to All...Please help me understands more. What could be the most possible root cause for the smps power supply voltage drop under load? Vout is measured 5V without load. But when load (2ohm) connected can get only 4.7V...This smps specs is 5V, 20Amp...Please share your knowledge...thanks.
I dont use anymore 78xx linear regulators today unless I have very low amps consumption < 20mA or so or really adapted to the input voltage no more than 2V, or you're sure it will heat a lot. else I use a smps regulator, they are widely available and cheap and dont overheat search for LM2576 and family.
Dear All, Required Guidance, Design specifications are as follow; 1)Input voltage : 90VAC - 270VAC (Universal Range) 2)Power Rating : 100W 3)Output voltage : 1VDC to 80VDC 4)Output Current : 100mA to 2A If we go with Flyback Topology,which control IC suits best for the application as duty cycle variation is an external function.
Hi i am supriya, i have a smps with 230 constant input to constant 12v dc output , frequency 50Hz, 2A. But i need variable ac input from 180 to 280 ac voltage to constant dc 12 v, i need a circuit can u plz suggest me.
I am trying to make an smps. While powering the smps ,it is getting tripped. It works same even we power using 230 VAC without driving signals.(gate trigger) After MCB get tripped,if i power the PWM driver board(12V), it works fine and gets some voltage in the output and gradually disappears as capacitor discharges completely. (also (...)
How do you exactly measure the transistor voltage? A small probe compensation error will ruin any accurate voltage mesurement.
In such an smps, the output of the bias winding is often filtered to prevent peak charging of the bias rail capacitor to a voltage that could damage the pwm controller. Is this only done with modern pwm controllers which draw very low operating current?
Expected current at 12V DC is around 4 A according to TEC1 12706 datasheet. If it's considerably lower, the peltier element may be damaged, e.g. due to previous overheating. Or you got a fake device. I presume you have a DC clamp meter. If the smps is a multi voltage PC supply, 12V may drop with unloaded 5V. In any case check the voltage, to
The oscillation has high Q and is stoked up by the bus voltage ripple pulses. The magnitude is too low to cause any problems, I guess about 50 mA (*) rms. Of course it can be reduced by placing a RC snubber parallel to C7. *Actually 25 mA rms.
In the third page (top left) of the following document, it says that the crossover frequency of voltage Mode smps's must always be above the power stage LC resonant frequency.......... (its actually called page "24", even though its only the third page) ...Isn't this missing somethi
For a Full Bridge smps in current mode, as opposed to voltage Mode, we can say that with Current Mode, we no longer suffer the double pole of the output LC stage, because current mode control cancels out one of these poles, meaning that we can more easily compensate the feedback loop to attain this correctly worded?
hi I want to design the smps with below specifications: Vin=220 Vac Vout=1KV to 30KV , Iout-max= 20mA I want to use LLC for it. Is it possible to use LLC for this converter? I want to calculate resonance elements and transformer turn ratio and primary and secondary turns and inductances. The maximum voltage and current that drop on resonan
Varistors are usually used to suppress voltage transients, so you could use them to suppress transients on the primary side
over what time span would the voltage vary?
I'm having basis electronic knowledge & i can understand what happening inside of a smps, but still i can't start my first own smps design. I fear to start my design, its because of the risk of high voltage. Please provide some ideas for beginners... Where i can start for learning, from transformer or electronics circuit? I believe (...)
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 circuit would run of this voltage and apply 325V pulses to a transformer which would then r
Huh? 1)Why do you need to go through three stages to get to your desired 3.3 volts? 2) Why do you need to put anything in parallel? 3) LDOs only advantage is that they have a LOW DROPOUT. If you are going from 22 to 3, that's obviously not an issue. thank for being "VERY SERIOUS" about LDO , i thought they dissipat
Hello everyone! I am at prototype stage of making power supply like in title. The problem is my output is 10 times smaller than it was expected to be - i have 0,33 V instead of 3,3 V . I have no clue what could be wrong, circut on the board is ok, transformer also seems to be ok. Any suggestions will be checked instantly, thanks for any response
I have an smps battery charger circuit that charges 12.7AH 12 Volt Battery using UC3909 & UCC3809 from 120V AC. I post this below. Can I modify it to charge a battery of 200AH capacity 24V at a rate of 40A while input voltage will be 220V AC? Plz anyone help. 80784
Usually a DC feedback is applied in simulation to put the circuit into the intended bias point. For circuits with moderate gain, it may be sufficient to vary the input DC voltage manually until the bias point is reached. The circuit skips the LT1243 error amplifier and feeds the OP output directly to the comparator section. That's possible in pr
Hello, Is it a specific frequency, or is it a trace on a bode plot? In Marty brown book he shows an RC circuit and shows bode plots for it and says it is a "pole"..........but what is a pole? Is the pole the frequency at which the voltage transfer function through the RC circuit goes down by 6dB?....or is the RC circuit itself a pole?.....or
I was thinkig for 275V AC rating (for clarification). It gives fair margin vs nominal line voltage 220-240 and remove unwanted stuff.
Hello, Equn 3-58 on pg 290 of Basso's book (switch mode power supplies), gives the error amplifier transfer function for the case of R(LED) being connected to vout of the smps.....However, what is the error amplifier transfer function when the R(LED) is connected to a regulated and fixed bias voltage ? (ie as in fig 3-41 of pg 294 of Basso's bo