Design Me A Transformer, I Will Pay

Nothing to show us?

You might review 70V/100v public address distribution transformers. These may have multiple windings for separate loads, that could be reconfigured as autotxf.

Higher powers might be a stretch.

RL

legg wrote in news: snipped-for-privacy@4ax.com:

The old transformer coupled PA systems? Yeah... Isn't that 70.7 Volts? Hehehe...

Yes most do have multiple windings. Some have several.

Of course not. He has probably never designed an amplifier. He is just a repair service.

As noted elsewhere, many people here who work around electronics, but don't actually understand and can't design electronics, are foul and angry. Not always, but too often.

I've seen that in Silicon Valley: the techs and pcb layout people resent and mock the engineers. Well, the male ones do. There are two distinct cultures.

In sed, the more competent people are at electronic design, the friendlier and more helpful they tend to be. And the more they show their work. And they use their real names.

Electronic design is sorta scientific, but personality matters. Schools should teach that.

I was playing with this,

a 50/60 Hz power transformer. Leakage inductance is microhenries, and it's pretty good out to 100 KHz.

It's a shame. Phil has so much to offer technically, but he has no control over himself if someone disagrees with him. Instead of replying with helpful technical information, he insults the poster who he thinks has less intelligence than himself. He thinks he is the final authority in that particular thread.

I think that is the OP's answer. Good suggestion, John.

I would recommend the 1182S30 part. What do you think?

It doesn't have the config he wants, one CT winding. He could only use half of the copper, if that, and it probably wouldn't work for him at

20 Hz. But a toroid roughly that size, or maybe a few notches bigger, could work.

He could use the Hammond for breadboarding, to get in the ballpark.

Yes. The core area needs to be three times larger to handle the 20Hz. So choose a transformer for 3 times the voltage at 60 Hz or 180V. The windings can be put in parallel to double the current. The primary and secondary would be wired parallel with each other and in series after that.

Like this:

Version 4 SHEET 1 880 680 WIRE 64 -32 -64 -32 WIRE 176 -32 64 -32 WIRE 64 0 64 -32 WIRE 176 0 176 -32 WIRE 64 96 64 80 WIRE 176 96 176 80 WIRE 176 96 64 96 WIRE 64 112 64 96 WIRE 176 112 176 96 WIRE 64 208 64 192 WIRE 64 208 -64 208 WIRE 176 208 176 192 WIRE 176 208 64 208 SYMBOL ind2 48 96 M180 WINDOW 0 36 80 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName L1 SYMATTR Type ind SYMBOL ind2 48 208 M180 WINDOW 0 36 80 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName L2 SYMATTR Type ind SYMBOL ind2 192 96 R180 WINDOW 0 36 80 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName L3 SYMATTR Type ind SYMBOL ind2 192 208 R180 WINDOW 0 36 80 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName L4 SYMATTR Type ind

------------------------------------------

** Finally, someone actually bothered to find out a few FACTS.

FYI:

I did similar tests on commercial torroidal trannies over 30 years ago.

Similar models to above ARE regularly used in output stages of high quality tube amplifiers and some musical instrument amps. The low L leakage inhere nt in the design of toroidals plus having very low I mag numbers gives them to excellent specs, plus lower costs than EI types.

Those with NO direct contact with the world of audio electronics, pro or do mestic, would be VERY unlikely to know this.

One gets to know by looking inside a lot of stuff that needs repair, then r everse engineering it to see just why it failed, works so badly or as works as well as it does.

Of course not many audio techs do this, but curiosity gets the better of me all the time.

.... Phil

-------------------------------------------

** Bullshit.

Disagreeing is one thing, posting absurd crap, defamation and deliberate LIES blown one's arse quite another.

Anonymous, brain dead trolls like "John S" are incapable of seeing the difference - cos Mr Shithead is an absurd narcissist with delusions of grandeur.

Plus he is a vile arse licker.

Only the most pathetic creatures get any joy from doing that.

..... Phil

Phil still denies that Belfuse made 'Chemical Fuses' for TV sets. They were plug in, with different pin types foe each amperage. They were about the size and shape of small PCB mounted relays.

I edited your post, it's an impressive partial resume. You must have lots of interesting stories to tell.

--
 Thanks, 
    - Win

On Friday, September 13, 2019 at 11:25:00 AM UTC-4, Winfield Hill wrote:

Win, I was sick as a child, so I read everything that I could about electro nics. I built a radio from a kit on my eighth birthday, and I was working p art time in a TV shop at 13. I was rejected by the draft board because of m y health at 18, then drafted at 20 because I worked on industrial electroni cs. In Basic I was given two choices. Cook, or drive a supply truck. I told of an old E8 and a Captain as I told them that I wasn't going to do either . They decided to prove that I didn't know any electronics, so they arrange d for me to take a 110 question, two hour 15 minute test. It was supposed t o be the hardest test n the Army, and it was given at the end of a three ye ar engineering school for 'Proficiency Pay' after five years in the field. The average score was 22/110. They claimed that the only copy they had on f ile was missing two pages, so they gave me 88 questions. I finished it in 1

7 minutes with a score of 82/88. It was the highest score ever on that test , and I was awarded the MOS which was a combination of EE and Broadcast eng ineering. While in the Army I worked in CATV, which was a pair of 12 channe l systems to feed Weather data to the flight school on two channels, and te n channels of Educational TV to the Helicopter flight school, and the Infan try classrooms. We designed and built was possibly the world's first interf ace to take control of the civilian CATV system on base during emergencies.

Our section was known as Weathervision. We were only allowed 15 minutes of downtime without closing the flight school and 17 airfields. While at Ft Ru cker, I worked with CATV, maintained over 300 large video monitors, and var ious smaller systems including Jerrold AM CARS microwave links. I was loane d to the RADAR section when they were short handed and they had a sudden ba tch of failures in vintage, tube base Korean era portable systems. Regulati ons required two men on site, because mistakes could be fatal.

The tech I was assigned to work with was like Phil. 'You might be OK around a TV set, but RADAR... I told him that RADAR was simpler than TV because t here was no Aural circuits, and at that time there was no Chroma to deal wi th. I found the problem at every site before he could unpack his tools.

My next assignment was in Alaska, at a former WW-II Lend-Lease site that wa s known as 'Delta Field' I was the engineer at a military radio and TV stat ion. it was in shambles, and averaged more than seven hardware problems per broadcast day. Everything was 'Depot Level Only' work, but my MOS was Depo t Level. We had a locked supply room, but we were lucky to get projector bu lbs for the RCA 16mm film chain projectors. Depot had been due to repair so me of the equipment for over two years when I arrived. We had two TV transm itters, and one AM transmitter. One TV transmitter was 90W, and the newer t ransmitter was 500W. The video was out on the newer transmitter, and the au ral was out on the low power unit. This combination resulted in inverted po wer levels, since Intercarrier Vestigal Sideband Video (System M) was suppo sed to have the Aural well below the Visual carrier levels. It screwed up t he AGC on cheap, imported TVs. Most of the video monitors and Waveform moni tors were defective. There was a lot of defective, or unnecessary cabling i n the control room and studios, along with bad telephone wiring in that old Russian pilot's mess hall and barracks building. It drove me nuts. I fough t with it for months, until the useless Supply Sargent went on three weeks leave. He took all three sets of keys with him, without even leaving us rep lacement projector bulbs. He hadn't even left our parking lot when I lost t he rest of the 90W transmitter.

I 'went over the wall', literally. I used a step ladder to lean down into t he supply room to unlock the door. I was back on the air a few minutes late r, but I knew that I would be in trouble so I just kept working all three w eeks. I used 1400 line items totaling over 2100 parts as I repaired everyth ing on the TV side. That including making a replacement TV tuner for a piec e of test equipment.

The lifer station manager was pissed off He was quite short, and I had move d the critical equipment to the top of the equipment racks so I didn't have to get on my knees to make adjustments. He tried to have me Court Martiale d for 'Dereliction of Duty' and 'Destruction of Government Property'. That lasted less than 15 minutes. My company commander gave him a choice of putt ing me in for a promotion, or his being busted down to E1.

Two star Lt. General Marks came 105 miles on the Alcan Highway to personall y put my SP4 pins on, and to give me a letter of commendation. He told me t hat the station had been his biggest problrem, for years, and that they rec eived enough complaints each year to fill five drawers in his filing cabine ts. He said, "This station was the biggest technical joke of any branch of the US military in this region of the world. You have turned it into the be st operation facility, single handedly." I also managed to transmit our sta tion ID in color, from a monochrome only faculty to show that the Base Info rmation Officer didn't know anything about TV broadcasting. I used a hand m ade 35mm slide, a Heathkit colorbar generator and the crude mono video keyi ng built into the RCA video switching system. 15 seconds after I used it, t hat Lt. was on the phone screaming, "Soldier! You've just made a fool of me !" I reminded him that he was a self made man...

I left the Army after that assignment. I worked in a lot of areas in Electr onics. Everything but Medical. I sold business radios, and serviced them. I did commercial sound work from anther business that I owned. I serviced in dustrial controls, and engineered at two TV stations. The first was a 5MW U HF station on a 1700' tower in Central Florida. There, we needed to monitor the tower lights at our alternate transmitter site. I used a spare Aural c hannel on the STL to transmit a crystal controlled 1,024 Hz signal that was turned off when all the lights were on. At the main site, a LED was on all day long, until the beacons started flashing. We got a letter from the FCC requiring that monitoring on a Friday. If we didn't have a system in place , we would have had to spend thousands on an approved system. I designed it that evening and built it on my home workbench. I drove to the transmitter sites next day to install and test the system. It cost about $7 for the co mponents. The FCC approved it from my sketches that were included with the form letter we sent them.

The other TV station was in Destin Florida. I built it from an empty prefab steel building as the 'Engineer of Record'. I moved and rebuilt an early '

50s RCA UHF transmitter that made it through final test on the day that I w as born.

I consulted at several AM Radio stations, and ended my career building high grade Telemetry equipment, including on kU band system for the ISS. Even t hough my job title was 'Production Test Tech' I worked in Engineering to br ing the first DSP based system from prototype to production. That also invo lved upgrading our in house reflow process, building test fixtures and writ ing test procedures. I had a reputation for doing things my way. Some proce sses were so outdated that they wasted a lot of money. My motto was 'Do the best that you can with the tools and materials available, yet strive to do better' which meant to keep your eyes pen for better raw material and test equipment, along with better methods. Some of the engineers would come to the production floor to ask obscure questions about the newest test equipme nt, rather than wade through the manuals. I was often asked to evaluate new components, or for help in the Metrology department since one of the items I worked on were our custom embedded controller boards.

There are many more stories. I was blessed with an interesting life. If my health was better, I would still be working, since I had never planned to r etire. I told people was to not wake up one day, or to be found slumped ove r my workbench on that last day.

Wow, I knew you had interesting stories to tell! 1400 line items totaling over 2100 parts, Hahaha!!

I usually save stuff like that in a little NotePad file, but yours was too long and dense, so I plopped it into a Word file, 3 pages long, and saved myself a .pdf copy, named Michael-Terrell_stories.

--
 Thanks, 
    - Win

Winfield Hill wrote in news: snipped-for-privacy@drn.newsguy.com:

The only 'story' the asshole should not have told is the one where he berated Usenet news posters.

He said I lied when I said that I was in the service. For that characterless act... FUCK MIKETARD TERRELL.

Reminds me of his "I told of an E8 and a captain once" story.

Terrell's problem is not the things he did over the years. His problem is his pathetic, Trump like dismissal of others.

For that, he deserves it right back in his face. A nice right cross across that filthy, infected jaw of his.

Karma never forgets.

-----------------------------------------

** Michael Terrell wrote a pile of demented ramblings that reek of a narcissistic mental illness.

Win is a fool to take any notice of him.

** Terrell is a grossly autistic egomaniac.

No sane person posts their life story ( with them as the central character & hero ) in order to prove their correctness on some utterly unrelated matter.

Only grandiose lunatics do that.

..... Phil

Thanks, Win. I liked challenges. I would take on the jobs that no one like, just to find out what was wrong. Once I got the ECOs that I wanted, the ot hers would complain, "But, Mike gets all of the easy stuff!" to be reminded that some had been threatened with being fired to get them to do that job.

At one time I would come home after a long day of work, and wake up in the middle of the night with the answer to a problem that no one else had solve d. The downside was that I tired quickly of things once there were no more problems which took most of the fun out of my hobby of collecting old radio s and test equipment. Once it had been cleaned up and worked properly I wou ld have to get rid of it. I have kept a few rare items, but at this point i n my life I will have to start selling off and giving away more of my stuff .

Life can be fun or boring. I chose to take risks, and to enjoy it for as lo ng as possible rather than a mind numbing job. I took joy in living, and in helping others. I could have had a nicer home and more in the bank right n ow, but you can't take anything with you when you leave this Earth.