PWM..... What is the attraction?
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It started as an hobby at age 12, ECC83 and EL84 vacuum tubes. My first transistor sine oscillator used a light bulb to stabilize the gain of the amplifier.
Later, this turned into a profession after having absorbed all the complex math behind the scenes.
Even now, after retirement, I still have a lab for - mostly enjoyment, since I do all the testing on the circuit simulator. I kept a penchant for analog design, which remain tough now as it was fifty years ago.
PWM was the shortcut many took to keep life simple, but has never been a satisfactory design solution, especially in the 20 - 60 Hz range, as Rossum said above.
I didn't use a 555 in my designs. I Used a comparator like the 339, with a simmetric sawtooth waveform on the inverting input, and a control DC signal on the non-inverting input. This way I had separate and linear control of frequency and duty circle.
Back then, I hadn't the need to stuff circuits into a matchbox sized casing.
Back to the present day. .. I see the renaissance of PWM mods at same as I see the return of vynil audio, funny and memorable.
One last thing, which may upset some... IMO, it is better if people buy large PWM mods instead of large mech mods, truly...
Later, this turned into a profession after having absorbed all the complex math behind the scenes.
Even now, after retirement, I still have a lab for - mostly enjoyment, since I do all the testing on the circuit simulator. I kept a penchant for analog design, which remain tough now as it was fifty years ago.
PWM was the shortcut many took to keep life simple, but has never been a satisfactory design solution, especially in the 20 - 60 Hz range, as Rossum said above.
I didn't use a 555 in my designs. I Used a comparator like the 339, with a simmetric sawtooth waveform on the inverting input, and a control DC signal on the non-inverting input. This way I had separate and linear control of frequency and duty circle.
Back then, I hadn't the need to stuff circuits into a matchbox sized casing.
Back to the present day. .. I see the renaissance of PWM mods at same as I see the return of vynil audio, funny and memorable.
One last thing, which may upset some... IMO, it is better if people buy large PWM mods instead of large mech mods, truly...
I also remember that era... From simple transistors to
LSI, then came VLSI....
Ha, the fun we had when I tried to tell my dad that my VIC20 had 3.5K of ram!
Of course he did not believe me, the new computer at his office cost just shy of £2,000,000 and only had 1024 Bytes....
And a 2MB hard disc platter was close to £15,000.......
Now we have terrabytes on a chip smaller than a thumbnail.....
Oh, I remember those hard disk platters. State of the art at the time with more storage "than you'll ever need". As I now type this on my 256 GB phone.
Off topic, but in the vein of the current conversational turn. This is one of the network printer mainframes I serviced. 180 pages per minute, stitching, binding, and mainframe channel or network connectivity. Generally used in data centers and print shops.
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I was a navy radio officer, and yes, used a little of valves (as we limeys call them)My electronics training was in the 50s
(replaced a lot of rectifier tubes)
Tetrodes, pentodes etc..
One of our old marconi marine radio used to use double walled valves and we pumped cooling water round them....
Still use them for some machines today...
Not the water cooled ones, but still use triodes...
I remember the 1st Computer I bought that had a Internal Hard Drive. It came with either a 105mb or a 210mb HD.(That's Megabyte with a "M")
The Sales Tech asked me what I was going to Mainly use the Computer for? I told him it would be used to do CAD/CAM.
With absolutely no hesitation he then said, "Oh... Then go with the 210mb HD. Because you will Never fill it up."
LOL
Like the data centre system....
I used to work on Logabax, sperry-univac and Burrough systems years ago....
Data terminals with 8bit core memory, and data spacing on the tapes that was so low, we used very fine iron filings and a ruler to align the heads
Am beginning to feel that I may not be a teenager any more
I used to work on Logabax, sperry-univac and Burrough systems years ago....
Data terminals with 8bit core memory, and data spacing on the tapes that was so low, we used very fine iron filings and a ruler to align the heads
Am beginning to feel that I may not be a teenager any more
OK, time for a survey. How many are still using a tube Amp or preamp at home because it sounds better?
Guilty as charged
Besides sounding better, it can heat the whole house.
Still use an analog tuner too
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Also guilty....
I am using a valve amp on my radios because the modulation really is noticeably better. My license limits me to ERP of 100w (till I get to next level) and so every bit of assistance I can get is necessary. And it tunes in lovely... I get far better performance than from the Italian company....
I am using a valve amp on my radios because the modulation really is noticeably better. My license limits me to ERP of 100w (till I get to next level) and so every bit of assistance I can get is necessary. And it tunes in lovely... I get far better performance than from the Italian company....
Sound Better?
At my age, and with the things I did in my Youth, a 160VBR MP3 encoded from a CD I bought at a swap meet sound about the Same as a Digital Master Recording off a Studio Sound Board.
Why on earth would you want an amp with high THD?
It's supposedly all about the 2nd order harmonics...
And there is the box of tubes for rolling.
This is the last one I worked on.....Seems like everything back then was based around this ole bird
For home stereo I have no issues with current hybrid solid state surround sound systems. Less is more these days.
I have a 60W Peavy Vypyr Hybrid Tube amp for guitar. Dual 6L6 Tubes are in the output interfaced with solid state effects on the front. You get the tube crunch and grind plus the beautiful sound of a complete set of effects pedals built right in. Over decades I've owned Vox, Fender, Marshall, Gibson, and a few other 4x12 stage amps. These days I'd just as soon put a mic in front of a combo amp and rock without having to haul the huge cabinets around. It's more about getting the sound off the stage and using in ear stage monitors.
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Loving the work talk about high tech stuff.
Anyone want to talk about PWM anymore or did we wear that topic out?
Anyone want to talk about PWM anymore or did we wear that topic out?
As with most topics it went from "do they work and how good" to "well this is how they worked back in the day.
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