Isolated, regulated, toroidal step down transformer AC power supply design.

Anyone who is genuinely mystified by my belligerence, either:

a) Didn't read or understand the thread and the chronology of its development.

b) Doesn't understand the basic rules and principles of equality, or understands them but does not apply them in newsgroups and believes that different criteria or rules should be applied.

In which case, it would be helpful if you explained the basis on which you discriminate between my belligerence and Phils (or anyone else's.)

Yes it is.

Because I believed the voltage of the AC domestic supply was straying outside the operating range of the existing regs (after transformation and voltage doubling rectification) and because I wanted to replace an existing wall-wart AC power supply with a regulated AC power supply and because the application displays errant behaviour during times of over voltage supply.

Whatever criticisms you can make of my reasons, they are there in the thread about 10 times. You didn't read the thread.

If I wished to spot UFO's, I don't think I'd need earplugs, of any description.

**Nope. That ain't it. I've been here since the start. I asked you what the application was. I also asked you what Voltages you had measured on the regulator inputs. So far, no answers. **Here's how it works in the real world:

• You ask a seemingly reasonable question (from your, very un-knowledgable viewpoint).

• You are asked to supply more information, so WE (the knowledgable) can decide if you request is reasonable or not.

• After we are supplied the information (which includes Voltage measurements), then a better solution can be supplied.

**I'm not discriminating between yours and anyone else's belligerence. I am simply stating fact: You are acting belligerently. And, in several annoying ways:

• You persist in top posting. Think of it in terms of a normal convesation. One person makes a comment and the other person responds, AFTER the original comment. Top posting reverses that convention. A convention which us humans have dealt with for many thousands of years. Top posters seem unable to understnad this uttery basic fact of life.

• Despite repeated requests, you STILL refuse to supply basic information about the device. You tell us what speakers you use, what capacitors you use, you even tell us about your family life, yet you STILL refuse to supply the fundamental information required for us to give you a sensible answer.

• Despite repeated suggestions that we have superior solutions, you continue to return to your own, quite insane one.

• Depsite repeated advice that your regulators are unlikely to be faulty, you persist in insisting that they MUST be faulty, when it is more likely that something else, far more prosaic is obviously wrong (that the regulators simply do not have enough input Voltage).

--
Trevor Wilson
www.rageaudio.com.au

Neither are we compelled to answer you civily,

yup.

yeah, if that's what is needed, usually it isn't, as a result such supplies aren't common

Bye. Jasen

Give up Trevor. Even if he coughed up the info, he wouldnt understand the suggested fix. Although its hilarious that he cant measure ripple current but wants to build a 1% AC regulator.

and its more pig-headed than belligerent behaviour - one can be belligerent and right, which he is not.

I recommend a 2kVA true-sinusoidal UPS to fix the problem. but use monster cables to connect the 9Vac, and ensure the mains plug is gold plated. Hopefully whilst mark is earning the money to pay for this stuff, he will stop posting (top or bottom)

some people should not be allowed soldering irons. or keyboards.

Cheers Terry

How do people with city power run this device?

Have you tried using an online UPS, or active line conditioner, that has sine-wave output, (this won't be cheap) and then connect the ordinary powersupply.

Bye. Jasen

There seems to be a trend to put clear cases on everything these days... Maybe if you can shine a light through it you can measure its 'transparency'?

well, you atleast know the whole story, there's a chance that someone elee here has encountered a situation like yours and fixed it in a totally different way. If you want to keep secrets that's your problem.

We'll all just have to assume it's to power the irrigation controller for your attic hydroponics setup, os some monitoring device for a meth lab in your garage :)

FWIW the 50W subwoofer amplifier sounds like a good approach if you need regulated AC, maybe you can get one with a damaged speaker cheap on ebay.

for the signal generator maybe a Wein-bridge oscilator, or DDS.

Bye. Jasen

**Exellent point.

**Oh yeah. One of my mates wanted to install silver wire in his amplifier, CD player or something. I asked if he could solder and he assured me that he could. After the stuff stopped working, I told him to bring it down. YIKES! He was using acid flux paste to solder with. The corrosion was extensive. God knows what kind of iron he had. I gave him one of my old temperature controlled things and a roll of Multicore solder and an hour's worth of instruction. I haven't seen any of his gear back on the bench, so I guess all is now OK.

--
Trevor Wilson
www.rageaudio.com.au

Once again, your assumptions appear incorrect. The AC mains moves around a bit, usually to within +/-10%. Manufacturers know this and product is designed to handle it.

You have a little 9VAC wall wart transformer and these small transformers usually have poor load regulation so its output when lightly loaded is probably around 15VAC.

You don't have a voltage doubler, you have a pair of half-wave rectifiers which give you a bipolar DC supply which is unregulated. The unregulated DC supply is a good place to put those super caps, so as to smooth out the ripple in the supply to the regulators.

The regulators will accept a minimum of around +/-17VDC to regulate properly. With your wall wart, you probably have about 20VDC on their inputs so it works OK, until you load it down a bit. Then the wall wart AC output will drop and the inputs to the regulators will drop below 17V. Now your regulators will not be able to regulate. Your mystery circuit may not like this very much.

If you replace your wall wart with a better 9VAC transformer then your regulators may have an input below 17VDC most of the time and fail to regulate. You should probably replace the wall wart with a 12-15VAC transformer with good load regulation specs. Then your regulators will be happy with their input voltage and regulate all the time.

However, you must be aware that linear regulators get hot if they have a large voltage drop across them when under load, so you may need to make sure they are mounted to a heatsink to dissipate this heat.

All of this has been spelt out to you many times here by many people. Is there anything here you don't follow?

I think you'll find that you've offended Mark in many, many ways. What you think is logical, sensible advice based on the operating principles of the components involved is in fact a bitter, unjustified attack on him.

He's TOLD you what you need to know to help him, so stop crapping on about irrelvant thigs like "voltages" and "drop outs" and "specifications" and so-called "facts" and start agreeing that he's clearly suffering from a bad pair (!) of regulators and the one dual-rail power supply design in the world that only functions correctly with an insanely complex thing that generates regulated AC.

I don't quite see why an irrigation controller would need dual rails, but some kind of sensor that required an instrumentation amplifier might need it, and depending on how serious Mark is with his hydro setup, he might be sensing a range of parameters such as temperatures - both ambient and root-zone, CO2, TDS, PH and other nutrient attributes etc.

you probably only need larger heatsinks on the regulators, higher voltager reservoir capacitors and a slightly higher AC voltage input

it does not.

here's another way. .-||-+------------+------||--. | | | | | | o---+---o | F1 | | _-~ ~-_ | .-oxo-------+----|--+-~ : o---+---o : ~--+----- | | | : | : | --+-oxo-. ||| _____| | |~| | |~| | F2 3|||(_ === |\| | |\| === out "240V" 3|||(_ 36V | |_| | |_| | 240V +/- 9% +/-24% 3|||(________|_________|__________| --+-----' ||| ry1 ry2 | TR1  "+15%" "-15%" `---------------------------------------------

activating relay 1 will boost the output voltage by 15% use it when the input goes past 8% low relay 2 will reduce the output by 15%, use it when the input goes past 8% high, the circuit to tetect over or undervoltage and switch on the apropriate relay is not shown.

the relays should be rated to handle switching 48VAC and have atleast 1000V isolation, the fuses ( --oxo-- in the diagram ) sdhould be rated apropriately for thr transformer, the capacitors should be non-polarised about 1uF seems a good size.

a circuit not completely unlike the above is used at the power sub-station to regulate your power, but having it closer to the appliance means fewer compromises need to be made.

--

Bye.
   Jasen

save up your pocket money and get one of these: (or similar)

Bye. Jasen

Try again. Hint: he's not calling you "datasheet"

You aren't cooperating with those who attempt to help.

That's not a licence to be an asshole.

maybe you could cal;m down a little and look at it from our perspective

Bye. Jasen

7815s are good to 35V, do you want something worse?

How did you observe this? What do you mean by "clipping"? A regulated DC power 'rail' is supposed to be a flat line on the scope all the time...

Bye. Jasen

So you aren't the mark who attemped to mock Phil over some misunderstandibng of your voltage doubler?

you must be an imposter then.

Fuck off.

--

Bye.
   Jasen

(thinks....)

Between the primary and secondary windings - same as an EI

(I'm guessing that'd mean a layer of GOSS between the primary and secondary windings )

So a cross-section parallel to the windings would go, radially, GOSS core, insulation, primary, insulation, GOSS shunt insulation, secondary

that could be a problem.

Does an R core really regulate much better than a toroidial, they still have the primary wound on top of the secondary?

Bye. Jasen