I built up a new amplifier pcb.
Worked OK except for some small 30KHz oscillation.
Couldn't work out where it was coming from.
I then moved back my LED desk lamp to see better and the 30KHz disappeared.
I believe in running LEDs from DC.... period.
To hell with that interference-prone SMPS crap!
DC, pure DC, is silent, doesn't radiate from wiring, and doesn't transmit noise to other nearby components.
But of course, you all should know that.
The kitchen under-counter LED strips that I installed last May 2019 haven't given me any problems, along with the regulated DC (analog LM317) dimmer that I built.
400 equivalent watts of light that only draws 35W max.
To hell with that interference-prone SMPS crap!
DC, pure DC, is silent, doesn't radiate from wiring, and doesn't transmit noise to other nearby components.
But of course, you all should know that.
The kitchen under-counter LED strips that I installed last May 2019 haven't given me any problems, along with the regulated DC (analog LM317) dimmer that I built.
400 equivalent watts of light that only draws 35W max.
In the early 20th century, Henry Ford had an overwhelming lock on auto sales in the USA. Every few years, he found a way to keep making his Model T a little better, a little more durable, and a little cheaper. Consumers noticed, and bought Fords in droves.
Alfred P. Sloan was hired to General Motors to try and steal sales from Ford. His solution? Rather than try to beat Ford on price or engineering quality, he decided to just keep building the same crappy car mechanicals - but to re-style the body every year. Change the superficial external appearance, but not the underlying engineering.
Sloan wasn't shy about his approach: he said, in so many words "Many may wonder why the automobile industry brings out a new model every year. The reason is simple...we want to make you dissatisfied with your current car so you will buy a new one."
The strategy worked for GM, and was quickly imitated by the manufacturers of other consumer goods. A hundred years later, the iPhone 11 doesn't exist because it's better than the iPhone 10; it exists to make current owners of iPhone 10's "dissatisfied with their current phone, so they will buy a new one."
Not always, at least, not to the degree that is common now. Just in the era of blind consumerism we happen to live in.
Prior to Sloan, most Americans had been brought up to be careful with their money, to spend as little as possible, to cherish their possessions, and treat them as heirlooms to be passed on to the next generation. This attitude still prevailed a few decades ago in some countries where people had been less exposed to advertising.
Sloan, and other rapacious and unscrupulous marketers who followed his lead, quite deliberately worked to undermine that mindset, and brainwash Americans (and later, most of the rest of the world) into an entirely new set of beliefs, such as the often-quoted "You get what you pay for".
This last statement is so obviously ridiculously illogical that it's amazing that anybody believes it. If I take a $10 stapler and mark up the price to $100, it's obviously no better than it was at $10!
But when you're exposed to the lie constantly since childhood, most people do come to blindly believe it. And so, people have come to unquestioningly believe that if they spend more, they will always get a better product. Rather than actually assess the product to see if it's better, and then decide if its worth paying more for it, they simply assume that if it costs more, it must be better.
This is wonderful for manufacturers, who can increase profits on sales of an otherwise ho-hum product simply by jacking up the price, thus making it expensive, "exclusive" and desirable.
And to bring the thread back on topic - marketers and manufacturers like Apple Inc. are increasingly selling us products that cannot be repaired at all, or that are very hard to repair. When you repair a product, rather than just buy a new one, you're not just repairing a product, you're also striking a small blow for sanity in a world gone utterly mad.
-Gnobuddy
Gnobuddy, what you've mentioned largely is the sad state of affairs today.
And as I mentioned previously, it's disgusting, downright rude, and I'll even say it's criminal.
But, alas, delving into this topic more requires discussions that are not advisable on this site (political).
Because there's much more to the "consumerism" story than meets the eye.
I digress.
And as I mentioned previously, it's disgusting, downright rude, and I'll even say it's criminal.
But, alas, delving into this topic more requires discussions that are not advisable on this site (political).
Because there's much more to the "consumerism" story than meets the eye.
I digress.
Hi Gnobuddy,
Hopefully your automaker example isn't something you believe in to this day, because Ford lack of good engineering is the rule since at least the 1970 model year. Heck, in 1966 they really didn't do us any favors either! The same brake equalizer valve failed in the 1966 model Rustang and was still the same exact part that caused another accident to someone else I know in a 1982 Crapri. Our family has been in the car business a long time, body shop included. Did you know that Capri and Mustang seat support legs fall through the floor pan because it was made too thin. There is an secret factory brace for that problem, but Ford dealers will try to charge you for it. Recaro racing seats were ordered, and only the driver's seat was real. The passenger seat was a Ford fake! Then there was the fiber timing gear that would lose it's teeth (bye-bye valve train). Transmissions that shifted from park to reverse by themselves, the Pinto gas tank debacle. I could go on and on. How about using eccentric cams to align the front end? GM used shims that were bolted in in case you're wondering about poor engineering there. The air conditioning compressor that used a rubber o-ring to act as a spring (in the engine compartment, it was a large o-ring), the transmission in the Taurus (we went through three before 60,000 KM. Never had a transmission go before). The fuel line clips that were spring tension only (everyone else used the clamps with a screw to tighten them). Man, I could go on at length, and much longer if I used google.
-Chris
Hopefully your automaker example isn't something you believe in to this day, because Ford lack of good engineering is the rule since at least the 1970 model year. Heck, in 1966 they really didn't do us any favors either! The same brake equalizer valve failed in the 1966 model Rustang and was still the same exact part that caused another accident to someone else I know in a 1982 Crapri. Our family has been in the car business a long time, body shop included. Did you know that Capri and Mustang seat support legs fall through the floor pan because it was made too thin. There is an secret factory brace for that problem, but Ford dealers will try to charge you for it. Recaro racing seats were ordered, and only the driver's seat was real. The passenger seat was a Ford fake! Then there was the fiber timing gear that would lose it's teeth (bye-bye valve train). Transmissions that shifted from park to reverse by themselves, the Pinto gas tank debacle. I could go on and on. How about using eccentric cams to align the front end? GM used shims that were bolted in in case you're wondering about poor engineering there. The air conditioning compressor that used a rubber o-ring to act as a spring (in the engine compartment, it was a large o-ring), the transmission in the Taurus (we went through three before 60,000 KM. Never had a transmission go before). The fuel line clips that were spring tension only (everyone else used the clamps with a screw to tighten them). Man, I could go on at length, and much longer if I used google.
-Chris
Not at all. That was Henry Ford's philosophy, circa 1910 - 1920. A very long time ago.
Ford had other personal philosophies that were extremely ugly, and I'm certainly not holding him up as an example to all humankind. 🙂
The best-quality 1970s car I've worked on was my old 1973 Datsun 240Z. There was a lot of good engineering in that car.
But the point isn't Ford or GM or Apple or any single company. My point is that it's been a very long time since the underlying quality of a consumer product has been the primary driver of its popularity or price. And this state of affairs was carefully engineered - it didn't happen by accident, but by design.
-Gnobuddy
I’ve worked for a car company, in Detroit, they do actually count part costs in tenths of a penny, that kind of thinking opens the door for all kinds of corner-cutting...
Quality impacts sales very negatively. Manufacturers want sales to increase and the vast majority of customers have no clue how what they buy work. Business people are taking full advantage of the situation.
For many many people mathematics, physics and technology are gibberish, only nerds without a life like.
If you want to be cool, you have to browse facebook all day long, you have to like advertisements, you have to like buying the latest to impress, you have to have a lifestyle that is not necessarily what you would want had there been no peer pressure, you have to buy expensive phones to impress and change them as soon as new models are out, etc.
In other words, to be cool you have to be a puppet on a string at the mercy of greedy string pullers.
Nicely put. 🙂
IMO the idea that being cool is more important than being a decent human being is a belief that really destroys the personal happiness and quality of life of millions of people. I would guess that it is probably a significant factor in the decades-long rise in depression levels around the globe.
-Gnobuddy
Hi Gnobuddy,
Yes, I have to agree with you.
I would also add that corporations have a personality, and that personality tends not to change at all over time.
-Chris
Yes, I have to agree with you.
I would also add that corporations have a personality, and that personality tends not to change at all over time.
-Chris
Today I repaired a Galaxy S7 that was in a logic loop, and I put an AOSP based Android 10 build on my old Nexus 6P.
Also although it doesn't really qualify as a "repair", I pulled a nice Hoover out of the "garbage". After I cleaned it up it works perfectly 🙂
Also although it doesn't really qualify as a "repair", I pulled a nice Hoover out of the "garbage". After I cleaned it up it works perfectly 🙂
What you said is true.
And this situation goes much farther back in time than people think.
In fact, it goes back to those "biblical" days.
"Control"........ of the masses.
Control, mind control, utilizing things like "fear", "laws", "limits", "mandates", beliefs, among a plethora of other "powers" devised to keep you under control.
These things are ingrained into you from birth, and done so in such a subtle way that you never know it.
In effect, your natural born human freedoms are taken away.
And just to insure that you "stay" controlled, advertizing, among other propoganda, is shoved at you daily.
The other controlled part of society also insures that you stay in line.
The wild animals in the forests and jungles have more natural freedom than you do.
Think about it.
But I digress.
Repaired a couple ESL VideoBridge 2150/2160/2100 meters. Also figured out that the 2100 does not measure straight resistors. Well, it can, but not nicely - heck, without any grace whatsoever! Just push the "G/R" key and ignore the capacitance readings.
-Chris
-Chris
Changed old bad X2 capacitors in my Tektronix 2465A (in power supply module). I was very afraid to take it apart, but I knew I have to do that - I had obvious signs of high internal noise on the screen, it even induced HF noise onto circuits under test. All other modules had been serviced by seller (changed elcaps etc). Despite of my fears I re-assembled it ok, and after that it works fine now.
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Hi Vovk Z,
Excellent work! Sometimes you just have to take things apart and have a look for yourself.
-Chris
Excellent work! Sometimes you just have to take things apart and have a look for yourself.
-Chris
But!.........
When I was 8 or 9 years old, I "took apart" the family phonograph.
And I hid all the loose parts in the basement.
When my father wanted to play his Connie Francis records, I acted dumb about where the phono was....
And got beat down for taking the thing apart!
LOL! 😱
I was lucky like that. I used to take things apart to see how they worked, but most of the time the stuff was already broken and I'd end up repairing it.
I was about the same age when my parents upgraded to stereo, and I inherited the Magnavox HiFi. It took me about 2 minutes to cut a guitar cable in half and twist the bare wires to the wires in the Maggie's tone arm. Add a bit of masking tape, and I had my first "DIY" guitar amp.
By this time had already amassed a large stash of discarded stuff to take apart, but had not yet mastered the art of putting stuff back together. I did manage to "make" a working radio or two by swapping tubes around, but live TV set wouldn't happen until middle school. It took three identical TV sets and a soldering gun to pass that milestone.
- I did absolutely the same when I was about 7-8 years old 🙂. It was broken already so my father knew what he do when he said to me "Try to repair it" 🙂. Till the end of the summer (it was at my grandfather/grandmother home) only case had left. At this age if I taken something apart it was only one way ticket, it was well-known yet. 🙂
But in this situation with my Tektronix I am 40 years old now 🙂, and have internet, which helps a lot with photos and videos.
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