| red |
Hy guys,
I want to build a smps using rod elliott schematic.
Since he doesn't makes pcb's for this project I tried and made one myself.So here it is...can anyone see anything wrong except the fact that I have 2 wires not connected?
Those 2 wil have coper wires on the mounting face of the pcb, but my real concern are the mosfet's.The pcb soldering side will have thicker wires than in the picture.My concern are the mosfet's.
So please I need some feedback |
|
|
| paulb |
You should make the traces as thick as possible, especially in the high current areas around the MOSFETs. I assume this is double-sided? Some traces cross. You may want to try a single-sided with the other side all ground plane.
This looks like a tricky circuit to build. I assume you've got the right test equipment and some experience in this area. If not, try something simpler first. |
|
|
| red |
Ok some things to consider:
I will make it a one side pcb. I think youre sugestion with the other side to be grounded it's a very good one.
The traces That cross are actualy the same wire(Gnd in most of the cases). I have only two wires on the other side...one is gnd and one is 12v+ after filtering.
I will make everything as thick as I can (especialy the ones that are for the transformer and mosfets).The ground will be where it is possible even 2 or 3 cm thick.
And I may have the test equipment from my student lab, but I am not sure yet :D . |
|
|
| Tensop |
| the diodes on the rectification side will need to be a heatsinked package, eg to220 or 247 |
|
|
| red |
| Good point. I forgot about that... Thanks. |
|
|
| jackinnj |
National Semiconductor has an application note for their Simple Switcher line of SMPS chips -- http://www.national.com/an/AN/AN-1229.pdf --
you should take a look as it explains guidelines for traces, ground returns etc. It's a good first start. Some of the traces which carry a lot of current have high di/dt -- so their impedance has to be taken into consideration, even at relatively low switching speeds.
national also has some guidelines for using the LM3524 chip which is a "cousin" of the SG3525 -- they have a PCB layout for a switcher using the LM3524. |
|
|
| EnvisionAudio |
:eek: That layout will likely not work very well - if at all. There are several (I'm being nice) design errors in the layout. The entire layout should be about half that size, at most. The traces not only need to be appropriately thicker, but also routed so as not to radiate or pick up the HF current pulses. I see a lot of antennas on that board. Additionally, the first 20 ampere draw will vaporize a lot of copper. :dodgy:
Here is a layout undergoing testing and prototyping for use with just about any medium power amplifier a DIY'er would want to install in their car. It can handle up to 400W (audio) with ease.
Something along these lines should be your goal. Note that there are copper bus bars used in this design in addition to a 2 side PCB. |
|
|
| ssanmor |
Hello all.
Nice to see that there is still interest on the Project 89 in ESP.
I wrote that article about 2.5 years ago!
Well, in fact I have designed a very improved version of that power supply, as well as some other stuff, like Class-D audio amplifiers and another SMPS for 230V AC input. We are going to sell that online, all ready built and tested.
We are starting to develop the web page where you will be able to see lots of specifications and info on these and other future products. Please have a look at:
www.coldamp.com
It is still under construction but please be patient!
Best regards,
Sergio |
|
|
| EnvisionAudio |
I'm as small a company as you are, but will there be OEM pricing for your products? Or licensing? I might like to use those power supplies. :nod:
I'm assuming the 240VAC version simply uses a voltage doubler that can be bypassed for 120VAC operation?
Is this a similar design to the USMPS in the Yahoo groups? |
|
|
| ssanmor |
| quote: | | I'm as small a company as you are, but will there be OEM pricing for your products? Or licensing? I might like to use those power supplies. |
Nice to hear that. Of course we can talk about these things. Are you mainly interested on the amplifiers or the power supplies?
Please write to info@coldamp.com and we will be very pleased to give you all the info you need.
BTW: I don't know the yahoo groups SMPS, if you can post the URL...
Best regards,
Sergio |
|
|
| SupraGuy |
C'mon Sergio! Get cracking on those power supplies! I'm still waiting! :) :D :smash:
I'm actually working on a PCB for P89 as well, but it needs revision from my last attempt. My original plan was to make a controller board which could use different transformers and possibly fewer MOSFETS for a low power version. It looks like I'll be scrapping that idea. I might still be able to use different size transformers, but they'll have to be adapted to fit on a somewhat larger PCB.
Well... Suffice it to say that I haven't decided yet. |
|
|
| twits4twats |
Looked at your website...loking good
Thanks for the English Version
I just wanted to know if you do Kits as well as fully assembled and what the difference in Price is? Could you email me a price list?
I'm interested in the PSU based on the ESP P89. |
|
|
| ssanmor |
Thanks. The web page has only some basic info now, it is like a introduction card ;)
The complete pricelist will be available as soon as all the modules are ready to sell, we still cannot give you an estimation , sorry.
The plans are to sell the complete modules, assembled and tested, although I don't discard a collaboration with Rod Elliot to offer the boards and perhaps the difficult to get components, mainly for the car SMPS.
We are having problems with the e-mail address listed in the web (info@coldamp.com), so perhaps some info messages can be lost, sorry for that. We are trying to solve it.
As soon as all is ready, I will be glad to post some info in this forum.
Thanks for your interest
Sergio |
|
|
| twits4twats |
| Interesting! So we shall wait and see... |
|
|
| PowerCrest Labs |
Has anyone seen or tried building this stripped down version SMPS? It looks fairly straightforward. I've got to test it out, I just wouldn't mind hearing some feedback first! Especially on what would be an acceptable ferrite core toroid to use? I've got all the rest of the parts ready to go.
Copy and paste the link below into your browser address bar to see schematic, and then expand the diagram.
http://valveaudio.tripod.com/images/schematics/switcher1.JPG
Justin |
|
|
| Easyamp |
| And yet another sg3525 switcher. |
|
|
| Easyamp |
| Straight art-work if interested in building. |
|
|
| richie00boy |
| Nice! What core is that designed for? |
|
|
| Easyamp |
| use ferroxcube TX36/23/15 model 3c90 or similar. |
|
|
| richie00boy |
| Are you using full wave but not bridge rectification? Can't get my head round the rectification with those dual diodes. |
|
|
| 2pist |
| Nice work easy! what are the boards dimensions? And does the pic show the solder side of the board? The two diodes do make a bridge Richie. |
|
|
| Easyamp |
It's an overhead shot looking at the top, the bottom side is the solder side.
Demensions are: length 3.85" width 3.0" height 1.65". |
|
|
| Easyamp |
| Also, the shutdown pin is still grounded in the scem so if you need to add some control you need to remove the trace from pin 10 to ground and use the jumper for conecting your control or reconecting to ground. |
|
|
| richie00boy |
| I still don't get how those diodes can make a bridge as they are common anode. Somebody please make me look stupid with a diagram :) |
|
|
| Tekko |
| One is common anothe, the other is common cathode. ;) |
|
|
| richie00boy |
| Well, that's what I thought you would need to make a bridge. However, those dual diode devices are always common anode. At least every one I have ever seen in TO220 or TO247 has been common anode. |
|
|
| jackinnj |
| look at the datasheet for the MBR20100 -- it's common cathode. |
|
|
| richie00boy |
I meant to say common cathode.
Thanks for the diagram easyamp. Now it's clear. I've never seen devices connected like that, good idea Fairchild :) |
|
|
| EnvisionAudio |
I notice that there might be a clearance issue at the toroid's secondary leading to one rectifier. I know that it's easy to accidentally get copper bleed between traces when DIYing the boards. Also, some users may find that the output filter capacitors may not fit when packed together so closely.
Also, R10, R12, C14 and C15 on the secondary rails seem to be connected improperly. As it appears, the RC circuit is grounded between the R and C points. Shouldn't those be isolated from ground, series'ed and attached to the rails alone? For instance, R4 and C10 are connected properly...
I'm a little concerned about the GND connection point, too. |
|
|
| Easyamp |
| here you go some pics of one of the boards. |
|
|
| Easyamp |
| here's one after etch, tin, and drill. I need a better camera! |
|
|
| jackinnj |
| quote: | Originally posted by EnvisionAudio
I notice that there might be a clearance issue at the toroid's secondary leading to one rectifier. I know that it's easy to accidentally get copper bleed between traces when DIYing the boards. |
One of the best tidbits of advice I received was to use a GerberViewer to make sure that everything is at it appears. If you are doing a one-off you can fix the mylar with a xacto knife by scraping away the miscreant trace width -- but if you are sending out protypes for a couple hundred bucks you may get a dissapointment back when the FedX man shows up and two traces over-lap.
Free Gerberware Viewer -- search for "Penatlogix" |
|
|
| Easyamp |
hi EnvisionAudio
Sorry I'm running late for work but do have comments on those.
be back later.
Thanks |
|
|
| Tekko |
| OOOOO:bigeyes::cool: Its so i almost want one of these:cool: |
|
|
| Easyamp |
| The pictured smps is not finnished, the components are just placed in there also the toroid is not the one it's just there for looks. |
|
|
| Tekko |
| But still, i want one just because it looks so nice. Well done, Easyamp:cool: |
|
|
| PowerCrest Labs |
simple looking SMPS Post #15
Has anyone seen or tried building this stripped down version SMPS? It looks fairly straightforward. I've got to test it out, I just wouldn't mind hearing some feedback first! Especially on what would be an acceptable ferrite core toroid to use? I've got all the rest of the parts ready to go.
Copy and paste the link below into your browser address bar to see schematic, and then expand the diagram.
http://valveaudio.tripod.com/images...s/switcher1.JPG
Justin |
|
|
| PowerCrest Labs |
So EASYAMP, out of curiosity, Is this the same circuit I was talking about back on post #15?
Justin |
|
|
| EnvisionAudio |
| quote: | | One of the best tidbits of advice I received was to use a GerberViewer |
I agree - but I don't see a Gerber file here, only a screenshot.
I don't know if some of you have read the "SMPS PCB" thread, but I am working on an SMPS kit complete with toroid and heatsink and all the protection circuits onboard. You get a choice of a full heatsink with room for your amplifier - or just a 4" wide 'slice' that contains the power supply. The heatsinks are exactly the same as the old PPI ProMos series, but in black anodized - might do black powdercoat, but it's not as heat efficient. Any takers? |
|
|
| N-Channel |
Richie00boy and Jack,
Try looking at Onsemi's MUR1620CT and MUR1620CTR. These two diode pairs are both 16A (8A per leg) with a 200PIV ratings. The 'CT is common-anode, while the 'CTR is common-cathode.
The 'CTR forms the negative halh of the full-wave bridge, however, that type of diode pair is not used here. THe 'CT & 'CTR are used in commercial car amplifier SMPSs.
Steve |
|
|
| N-Channel |
Easyamp:
What is the core material? I have seen this (green) core before, but do not know who the mfr or type is. Thanks!
Steve
BTW, Nice board! |
|
|
| richie00boy |
| Thanks for the tip n-channel. I will make sure I look harder/more carefully when looking at dual diodes on future. |
|
|
| N-Channel |
Easyamp-
What is the transformer's core material. I've seen this core before, but don't know the type. Also, is there a website where I can find info on this? Thanks,
Steve |
|
|
| Easyamp |
Hi N-Channel I got a bunch of these on the cheap from a friend who got them from where ever. They are 59*002701 fair- rites or equivlents. They are wrapped with what looks to be 18 guage wire with 7 primary wires and 4 secondary wires and they are 1:2 ratio transformers. The are 2 seperate primaries with 4 wraps each which makes there frequency somwhere between 30 and 40k they seem to work very at 32k.
I do not plan on sending out for boards I don't need silkscreening or anything fancy, I can do the rest here.
HI PowerCrest Labs I have tried looking at your link before and I don't know why but I just get a hosted by tripod in the corner and no picture? |
|
|
| Easyamp |
| Oh forgot to mention the all red core ion the upper right is a rewrap to a 1:3 ratio. |
|
|
| PowerCrest Labs |
EASYAMP, thanks for responding, sorry your having trouble with the link. I got the same message as you. If you highlight the text below, and copy and paste it into your address bar, I guarantee you it will work.
http://valveaudio.tripod.com/images/schematics/switcher1.JPG
JUSTIN |
|
|
| Easyamp |
Hi PowerCrest,
The supplies are somewhat similar.
My output voltage with 13.0v in is 38Vdc+/-.
I returned my primary snubbers to V+ instead of ground which when done correctly can do almost as good a job with smaller discharge resistors.
The other design uses feedback, mine is unregulated.
Does the sg3524 have the same shoot through circuitry as the sg3525? |
|
|
| jackinnj |
If you are working on boards that you are going to offer, I would suggest putting in the soft-start circuitry, regulating the output, and a really good dose of EMI filtering on both inputs and outputs.
the primary reason for regulating the output is the wide fluctuation in input voltage in the auto application --
i just sketched this out for an application with a wide range of input variability, and current demand from 1.5 to 4 amps with a switch operating at 40kHz -- this will cover the range for a lot of amplifiers: |
|
|
| richie00boy |
| The diode symbols you have drawn there are what I have always known to be the symbol for zener diodes. Normal diodes are straight. I assume that these are in fact normal diodes? |
|
|
| N-Channel |
Rich-
Those are Schottky diodes. The difference between them and the Zener symbol is that theanode line is wavy, while the Zener's anode line is jagged.
Schottkys have lower forward voltage drop. Problem is, that currewntly, there is no negative pair for the Schottkys, only positive pairs.
Steve |
|
|
| EnvisionAudio |
| quote: | Originally posted by Easyamp
I returned my primary snubbers to V+ instead of ground which when done correctly can do almost as good a job with smaller discharge resistors.
[snip]
Does the sg3524 have the same shoot through circuitry as the sg3525? |
Ok, the primary snubbers are correct. I return mine to V+ also...
I am talking about the secondary snubbers. They are not placed properly - unless you are trying to do something else, because they're not going to snub anything in that current configuration. It just looks like a simple error.
The SG3524 does not have shoot through lockout. |
|
|
| Easyamp |
I will do i/o filtering and fusing off the board, case mounted. Soft start will be done with the supplied soft start pin and shutdown controls also small seperate small board.
cheers |
|
|
| Easyamp |
Hi Envision,
The resistors on the secondary are just there to keep the outputs from walking when the supply is unloaded. When they're not in there I get 10v on the neg and 60 some odd volts on the V+. The caps are just part of the cap bank. All noise filtering will be done off baord. |
|
|
| Alcaid |
Easyamp:
Have you tried the SMPS in your car?
What wire gauge are you using, and how many strands are you using on your toroid? Looks like very few. How much current could your trafo handle this way? |
|
|
| richie00boy |
| quote: | Originally posted by N-Channel
Rich-
Those are Schottky diodes. The difference between them and the Zener symbol is that theanode line is wavy, while the Zener's anode line is jagged.
Schottkys have lower forward voltage drop. Problem is, that currewntly, there is no negative pair for the Schottkys, only positive pairs.
Steve |
Thanks. I do know about schottky's :) I wondered after I had posted if they were those. It's always tricky with hand drawn diagrams ;) |
|
|
| jackinnj |
| quote: | Originally posted by EnvisionAudio
Ok, the primary snubbers are correct. I return mine to V+ also...
I am talking about the secondary snubbers. They are not placed properly - unless you are trying to do something else, because they're not going to snub anything in that current configuration. It just looks like a simple error.
The SG3524 does not have shoot through lockout. |
No, the secondary snubbers are drawn correctly -- they go across each of the diodes. the topology and formulas have been discussed at length and can be found on On-Semi's website, the Cornell Dubilier website or at hagtech.com
instead of the two schotky's you can use a bridge, or just use two power supplies. this configuration is really a push-pull buck supply. so there is no free lunch with the inductors. further, it would be better to use a current-mode controller than the SG3524. (a voltage mode controller.)
i should specify that the winding ratio is 6:48. The primary will be larger than #18, I just used that size since it fit into the widgedizer. |
|
|
| EnvisionAudio |
| quote: | Originally posted by jackinnj
No, the secondary snubbers are drawn correctly -- they go across each of the diodes. the topology and formulas have been discussed at length and can be found on On-Semi's website, the Cornell Dubilier website or at hagtech.com |
That's incorrect. There are not RC snubbers across the rectifier diodes in the layout. There are mylar capacitors from each rail to output GND and a resistor connected likewise. As Easy explained, they are not functioning as snubbers, anyway, but thanks for the reference... |
|
|
| jackinnj |
| quote: | Originally posted by EnvisionAudio
That's incorrect. There are not RC snubbers across the rectifier diodes in the layout. There are mylar capacitors from each rail to output GND and a resistor connected likewise. As Easy explained, they are not functioning as snubbers, anyway, but thanks for the reference... [/B] |
well, in fact they are acting as a snubber/zobel -- compensating for the ESL in the reservoir cap, compensating for the capacitance of the diodes and the leakage inductance of the transformer secondary. the snubbers pictured are optimized for a specific transformer/diode combination. ymmv.
you are correct in that the ESP snubbers are configured differently. to determine whether the ESP snubbers actually work, however, you should check out the supply with a spectrum analyzer (or an rf sniffer and an oscope) and see whether they are effective at reducing the radiation. |
|
|
| EnvisionAudio |
| quote: | | well, in fact they are acting as a snubber/zobel |
Ok, I see what you're saying. I wasn't referencing the ESP design - and I don't use it either, so I cannot speak to the design intent.
My designs use snubbers on the secondaries and tertiary winding (voltage feedback) whch also functions as the auxilary voltage supply. Primarily, they suppress instabilities at the 317/337 aux. voltage regulators. I find that a properly selected capacitor across the rectifiers rather than an RC combination is more effective, but I can see the reasoning for EasyAmp having balancing/ballast resistors. |
|
|
| PowerCrest Labs |
| I have read all the postings so far, and there has been talk about regulated vs non-regulated output, where a regulated smps requires feed-back from the rectified DC output rails back to the SG3524. Also talk of using LM317 and LM337 Regulators. I have always understood that regulated power supplies are not as good for driving audio power amplifiers because they lack the "head room" a good power amp needs to be able to output clean sound at extreme audio demands. That’s why no home power amp ever uses a regulated supply. If I am way off base, I would like to understand why! |
|
|
| Stuart Easson |
Hi, my 2c, and you guys get it for free...
regulation has it's place in amplifiers, and in fact the auto environment is perhaps where it has more application than in home equipment...
If the output of the SMPS is, say +/-3 * the input voltage, with no regulation, it will actually vary from +/-33v when the battery is cold loaded and low charge, to +/-42 when the battery is warm, unloaded and being charged. If a designer makes an amp to run from 33v, it is quite possible it will overheat or worse if subjected to 42v, and of course if you design it to run properly from 42v, then it probably uses more expensive or simply more components, plus it won't make full power unless the battery is in peak condition.
Regulation allows you to use the SMPS to compensate for the worst case battery scenario and still get the best result for the components your budget allows you to put into the amp. Here I'd opt for +/-4 * input voltage but use regulation to cap the output at +/- 40v, then when the battery is loaded you can still have full power from your amp, and it doesn't fry the amp when the battery is lightly loaded and fully charged...
Headroom is a very nebulous concept, it is rarely quoted by truly high end amps, and there is certainly no standard by which it is measured. One mans dynamic headroom is another mans inadequate power supply collapsing underload.
Hope that helps
Stuart |
|
|
| PowerCrest Labs |
Thanks Stuart Easson, I can appreciate your argument. That makes sense to me. I guess actually getting your smps to work in your car on a regular basis is another hurdle all in it self! I've never got mine off my lab bench yet :hot:
Justin |
|
|
| EnvisionAudio |
| quote: | | Also talk of using LM317 and LM337 Regulators. I have always understood that regulated power supplies are not as good for driving audio power amplifiers because they lack the "head room" a good power amp needs to be able to output clean sound at extreme audio demands. |
No, the 317/337 are used for the preamp (OpAmp) devices in the car amplifiers.
Regulation for the power amplifier in a car is a perceived value, but it can be murder on the switching elements. As input voltage drops, regulation is had by increasing Pulse Width (the PW in PWM) which draws more current. My designs are soft regulating which limits regulation over a smaller voltage variation and then drop completely out of regulation below a setpoint (about 10V). It sounds like a bad idea in theory, but in practice it works quite well and saves many Mosfets. :rolleyes: |
|
|
| jackinnj |
| quote: | Originally posted by Stuart Easson
If the output of the SMPS is, say +/-3 * the input voltage, with no regulation, it will actually vary from +/-33v when the battery is cold loaded and low charge, to +/-42 when the battery is warm, unloaded and being charged. If a designer makes an amp to run from 33v, it is quite possible it will overheat or worse if subjected to 42v, and of course if you design it to run properly from 42v, then it probably uses more expensive or simply more components, plus it won't make full power unless the battery is in peak condition.
Regulation allows you to use the SMPS to compensate for the worst case battery scenario and still get the best result for the components your budget allows you to put into the amp. Here I'd opt for +/-4 * input voltage but use regulation to cap the output at +/- 40v, then when the battery is loaded you can still have full power from your amp, and it doesn't fry the amp when the battery is lightly loaded and fully charged... |
that's why I plugged in the values for min/max voltages from the battery + 9 to 14V with a nominal 12V , and a range of 1.5 to 4 amps on the output -- the latter value is a little outside the range I experienced with my bridged LM4780.
post-regulation will clean up some of the nasties on the rails -- the LM317/337 won't be up to handling the current and power dissipation -- a simple TL431 and pass transistor will, however. |
|
|
| Easyamp |
Hi Alcaid,
| quote: | | Have you tried the SMPS in your car? |
I have used others I've built but not this one.
| quote: | | What wire gauge are you using, and how many strands are you using on your toroid? |
The pictured toroid is just there for show and is not it the pictured core below is the one.
It consist of two 12 guage per primary leg and three 18 guage per secondary leg with an overall ratio of 1:3. |
|
|
| Alcaid |
| quote: | Originally posted by Easyamp
Hi Alcaid,
I have used others I've built but not this one.
The pictured toroid is just there for show and is not it the pictured core below is the one.
It consist of two 12 guage per primary leg and three 18 guage per secondary leg with an overall ratio of 1:3. |
Ok, isn't the 12 ga. very stiff and hard to wrap around the core?
In the article at esp's it's recommended to use 6 26ga. wires for the primary. I guess it's less work to use only 2 wires for the primary instead. Any other reason not to use more and thinner wires? |
|
|
| jackinnj |
| quote: | Originally posted by Alcaid
Ok, isn't the 12 ga. very stiff and hard to wrap around the core?
In the article at esp's it's recommended to use 6 26ga. wires for the primary. I guess it's less work to use only 2 wires for the primary instead. Any other reason not to use more and thinner wires? |
the current carrying capacity of a wire is directly proportional to the cross-sectional area -- at DC. as the frequency increases the current flow is forced to the exterior of the wire, so the relationship starts to break down.
in the ATX article from QEX the author uses a bundle of made of 3 strands of #22 wire on the secondary.
you will see a lot of different types of wires used -- sometimes it's insulated copper ribbon, other times bundles of magnet wire, or layers of wire --
the diameter of the wire you use will also be affected by the amount of heating that you can sustain in the core -- |
|
|
| Easyamp |
power supply update
I'm waiting for some transistor mounting hardware, but pictured is the basic layout. I've added the input filter, fuse, and primary voltage hook up which I made out of dead inverter.
The input filter is ferrite material with o.d. of 1 inch and pair of 18g wires wound in a litz configuration with 7 turns. The capacitor is 2,200uf 16v low esr type crossing primary filter input and ground. |
|
|
| jackinnj |
| how does the Miller Genuine Draft "top" fit into the supply :) |
|
|
| Easyamp |
| the input filter works well, it drops a peak to peak spike on the 12v input from 90mv to 4mv unloaded. |
|
|
| Easyamp |
| quote: | | how does the Miller Genuine Draft "top" fit into the supply |
lol, I guess I could of tidy up a bit. |
|
|
| jackinnj |
| you should always run an SMPS with a load -- |
|
|
| Easyamp |
| well it is but it's only 2 resistors in the cap bank. |
|
|
| Easyamp |
I just meant no heavy load.
Jackinnj
I'm curious, your thoughts on using a low resistance like .025 ohm in series with the +12v to the core to generate a .65v when the core sees 30 amps or more to use to disable the shutdown pin of the sg3525, which will shut off the outputs, to use as short circuit prtection for the supply.
I have tried it and it works but one obvious draw back would the loss of core primary voltage of a few hundred millivolts while under heavy load. Per primary volt the output makes 5 volts so i would loose a few volts on the secondary side, but it is quick and easy and works. |
|
|
| Easyamp |
| OOps left a source open on the upper fet. |
|
|
| jackinnj |
| unless you want to put a differential amplifier on that resistor it's not a great idea -- a better place is between the source and ground -- in the low noise design I am working on it's like 0.08 ohms.-- i am not using the SG3525, however. you can also pick up the current inductively. |
|
|
| Easyamp |
Thanks for your response but why do think I would need an op amp. I'm only using the transistor to increase the gain of the resistor which is suffecient to satisfy the circuit in a short or at least it has worked well on the bench.
Also the sg3525 has the ability to do pulse by pulse limiting through the shutdown pin which would mean I would need to combine the source to ground points of both sets of mosfets to protect bot sets of transistors. But monitoring the plus side it's done for you.
I am using an op amp on thermal regulation and it will look something like this. |
|
|
| jacco vermeulen |
| quote: | Originally posted by EnvisionAudio
I don't know if some of you have read the "SMPS PCB" thread, but I am working on an SMPS kit complete with toroid and heatsink and all the protection circuits onboard. |
I have a little trouble finding the thread.
Mind posting the exact thread name ?
Thanks. |
|
|
| jacco vermeulen |
| Ah, at last someone with a sense of humor. |
|
|
| Alcaid |
| Not the first one, read post #7. |
|
|
| EnvisionAudio |
| Well, that design disappeared last year with an extenuating circumstance. I've been holding off for a bit as I am working a bit too much at my day job. Something will materialize however - but probably as a partial kit... |
|
|
|
