PSpice Gain/phase model for S/H and quantization in software loop (digital SMPS)

Started by Klaus Kragelund in sci.electronics.design10 years ago 4 replies

Hi I have implemented a digital SMPS in a Cortex M3 controller. The feedback of the SMPS is done using the TL431 and opto coupler...

Hi I have implemented a digital SMPS in a Cortex M3 controller. The feedback of the SMPS is done using the TL431 and opto coupler feedback. The feedback is sampled by the ADC at 10kSa and the sampled values controls the duty-cycle of the SMPS. It is stable, but I would like to simulate the loop in PSPice. The ADC has sample and hold along with quantiziation that affects the gain/phase. Th...


series input parallel output SMPS

Started by bitrex in sci.electronics.design5 years ago 48 replies

I have a bunch of small 12 volt input ATX SMPS power modules each rated for 120 watts. about 14 bux each, surplus. Fanless 200 watt modules are...

I have a bunch of small 12 volt input ATX SMPS power modules each rated for 120 watts. about 14 bux each, surplus. Fanless 200 watt modules are harder to come by and significantly more expensive. I'd like to slave two together to get ~200 watts out, with the inputs in series. 24 volt 8 amp power bricks are pretty common. I found this whitepaper on voltage balancing SMPS inputs in serie...


SMPS +/-5V about +50V supply.

Started by Clive Arthur in sci.electronics.design3 years ago 7 replies

I want a switch mode PSU which will give me two ~2A outputs at 5V above and below a nominal +50V (say +40V to +60V) DC supply, ie +55V and +45V...

I want a switch mode PSU which will give me two ~2A outputs at 5V above and below a nominal +50V (say +40V to +60V) DC supply, ie +55V and +45V from +50V. I can probably work out some fairly clunky ways of doing this, but it seems possible that there's some topology particularly suited to this type of thing. Any thoughts? Cheers -- Clive


My first switcher

Started by George Herold in sci.electronics.design7 years ago 28 replies

Hi all, Well I get to do a SMPS. There are boat loads of IC's out there and I'm looking for recommendations. (I better go re read AoE3) I...

Hi all, Well I get to do a SMPS. There are boat loads of IC's out there and I'm looking for recommendations. (I better go re read AoE3) I need a number of output voltages. +15V, +5V, -5V, -15V. and +24V. maximum current of 0.5A on any one. My current plan is to run the whole thing from a 24V wall wart or brick. Price and size is not too much of an issue, I guess fewer external pa...


Toroidal Transformer Screening

Started by Syd Rumpo in sci.electronics.design7 years ago 11 replies

Hi Another magnetics question! I have a SMPS which uses a toroidal ferrite transformer. It switches at ~100kHz, works very well, it's not...

Hi Another magnetics question! I have a SMPS which uses a toroidal ferrite transformer. It switches at ~100kHz, works very well, it's not my design and I can't change it. However, it introduces noise at about 50kHz onto/into my electronics which causes a problem. After much experimentation, I found that putting an earthed screen around the transformer kills the problem quite dra...


Reducing SMPS noise

Started by Anonymous in sci.electronics.design6 years ago 43 replies

I'm working on a PCB that contains nearly 30 resistors in a ladder configuration, each step switched in or out by a SMT solid state relay. It's...

I'm working on a PCB that contains nearly 30 resistors in a ladder configuration, each step switched in or out by a SMT solid state relay. It's essentially a decade box for a specific application. The relays are controlled by a micro and all is powered by a boardmount enclosed CUI AC/DC switching converter, supplying up to 400mA. The resistors are electrically isolated from the SM


What does a "self-ballasted" LED mean ?

Started by Anonymous in sci.electronics.design8 years ago 7 replies

Could some electronics guru pleas explain what a "self-ballasted" LED lamp mean ? I have seen LED lamps, running off the AC line, and...

Could some electronics guru pleas explain what a "self-ballasted" LED lamp mean ? I have seen LED lamps, running off the AC line, and powered by a simple small 5V 1 Amp SMPS, but what exactly does a self-ballasted LED lamp mean ?


Groundplane under SMPS power inductor

Started by John Devereux in sci.electronics.design7 years ago 48 replies

I have seen designs where there is a cutout in the groundplane under the power inductor in e.g. a buck converter. Inductor is nominally...

I have seen designs where there is a cutout in the groundplane under the power inductor in e.g. a buck converter. Inductor is nominally a "shielded" one. I assume it is to prevent some kind of "shorted turn" effect? What do you think? Might a continuous plane be better? It could help to shield any field leakage and reduce emissions and circuit noise. I am asking generally, but say 1...


SMPS LC filter... not!?

Started by George Herold in sci.electronics.design6 years ago 4 replies

Hi all, I'm having a big fail when trying to make an LC filter for a CUI SPMS. There's nothing to the circuit. ...

Hi all, I'm having a big fail when trying to make an LC filter for a CUI SPMS. There's nothing to the circuit. Here. https://www.dropbox.com/s/xgesfnb3a6z0x1n/L-C-schem.JPG?dl=0 The problem is that no matter what I do to the Land or C's the output always has the same amount, (shape and size) of ripple. Here's a 'scope shot. https://www.dropbox.com/s/inv0w000gdm9le7/TEK0042.BMP?dl=...


Inductor Voltage Rating?

Started by Vladimir Vassilevsky in sci.electronics.design9 years ago 32 replies

I have to make low power SMPS operable up to several hundred volts. For obvious reasons, it would be good to use off the shelf SMT...

I have to make low power SMPS operable up to several hundred volts. For obvious reasons, it would be good to use off the shelf SMT inductors. In datasheets, they always specify inductor max. current, however they don't say anything about max. voltage. Any advice or relevant experience? Vladimir Vassilevsky DSP and Mixed Signal Designs www.abvolt.com


Electros in Series II

Started by Phil Allison in sci.electronics.design3 years ago 28 replies

Hi, just came across a Chinese made powered mixer with Class D amps and SMPS. Branded Fender model "Passport 150 Pro". The 4AT 20mm...

Hi, just came across a Chinese made powered mixer with Class D amps and SMPS. Branded Fender model "Passport 150 Pro". The 4AT 20mm AC fuse was blown and a replacement blew spectacularly at about 90VAC input. Plus a little smoke appeared.... Standard, twin voltage input for 120/240 - set to 240V. The smoke came from a pair of exploded "TVR" 14mm dia varistors connected across ea...


RF Quiet Wall warts

Started by Martin Riddle in sci.electronics.design5 years ago 59 replies

It's been a year or two since I listend to AM Radio, and in that time theres a new Roku box and linksys router. Well, I couldn't hear anything ...

It's been a year or two since I listend to AM Radio, and in that time theres a new Roku box and linksys router. Well, I couldn't hear anything on the AM band when I checked a week ago. So the quest was to find the culprits. Its these SMPS wall warts, they literly wipe out the entire AM band, and also some chinese LED lights( 15w equiv Grimaldi's ). Tossing the led lights are easy, the wall...


Removing voltage-multiplier-related flyback SMPS switching glitches

Started by Anonymous in sci.electronics.design6 years ago 13 replies

A problem encountered with medium-to-fast current-mode flyback switchers, when combining high-ratio multi-winding flyback inductors with...

A problem encountered with medium-to-fast current-mode flyback switchers, when combining high-ratio multi-winding flyback inductors with multipliers: When Q1 switches on, a large current surge flows as Cpump charges from Cmult1 via D2. At Q1, the surge magnitude is multiplied by the transformer ratio. On simulation, U1 senses this via Rs and cuts Q1 off instantly, crippling the switcher -- ...


new 30MHz to 300MHz switcher - worlds smallest laptop adapter

Started by Jamie M in sci.electronics.design9 years ago 64 replies

Hi, Here's a new SMPS switcher apparently coming out next year for...

Hi, Here's a new SMPS switcher apparently coming out next year for laptops: http://phys.org/news/2013-12-circuit-laptop-charger-brick.html It apparently has a "power reclaiming scheme" for higher efficiency, would this be conventional sync rectification or some other thing? It looks like power electronics is in for a big (r)evolution once the 300MHz+ designs start to spread! cheer...


Re-calibrating bench PSU

Started by bitrex in sci.electronics.design2 years ago 11 replies

I need another PSU on my bench and I remembered I had this thing in my junk closet, a SMPS-based supply from www.mpje.com. Something was...

I need another PSU on my bench and I remembered I had this thing in my junk closet, a SMPS-based supply from www.mpje.com. Something was wrong with it I couldn't remember but all I recalled was this is what the power PCB looked like, from the "factory" mind you:


Old school Push pull audio amplifier transformer flux managment

Started by mike daniels in sci.electronics.design10 months ago 13 replies

I have a switched mode power supply background and an looking at something like this for an old school audio amp...

I have a switched mode power supply background and an looking at something like this for an old school audio amp design. https://www.circuitstoday.com/push-pull-amplifier For SMPS pushpull we always used current mode control to assure the flux in the core does not walk all the way into saturation. Looking at these designs, none monitor or measure the current to assure the flux


Is Maxim now AD? If so, this set of SMPS eval boards is interesting

Started by Phil Hobbs in sci.electronics.design4 months ago 18 replies

Datasheet: A set of _nine_ nice-looking eval boards for their new analog-focused, low quiescent power switching regulators, all for...

Datasheet: A set of _nine_ nice-looking eval boards for their new analog-focused, low quiescent power switching regulators, all for $49 in a nice plastic case and all. Dunno if I'm brave enough to use a Maxim part yet, but som