No Analog electronics in UK?

Flyback said:

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Not only that, but the DSP board actually came with some code that could just be loaded in and it would work (control the 5w smps) ...but even though it was just a 5w buck converter, the dsp ran so hot that you couldn't touch it!!!......indeed software controlled smps feedback loops are pie in the sky..do you agree?

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Nope. I think SMPS's will go the way of disc drive and motor controllers and go all digital. And I don't see why you need a high power DSP for that since the feedback loop frequencies are typically on the low side. See this, for example. But time will tell.

Flyback said:

ok, thanks, I concede that, (not that I devoutly disagreed on it), anyway..The concensus appears to be that software controlled smps feedback loops are pretty much pie in the sky, and will be for many, many decades.
I remember being at a radar company, and we bought in these DSP controlled SMPS demo boards from microchip....they actually came with instructions and bits of sample code so that people could program the dsp and control the 5W buck converter demo board.
I had a go at programming it and failed dismally.

But that company's principal software engineer also was not able to do it.
I think that says it all about software control of smps feedback loops...."pie in the sky"

Not only that, but the DSP board actually came with some code that could just be loaded in and it would work (control the 5w smps) ...but even though it was just a 5w buck converter, the dsp ran so hot that you couldn't touch it!!!......indeed software controlled smps feedback loops are pie in the sky..do you agree?

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No, they have their uses - a prime example is the PicKit series of programmers, which use a software SMPSU to generate the different programming voltages required.

It's really down to the 'reason' for wanting to do it - for a bog-standard PSU (such as TV or DVD player etc.) there's no point or advantage - but for the PicKit programmers it's gives you a completely 'free' SMPSU, the processor is already there and it simply utilises spare processing capacity to implement the PSU section.

If you couldn't manage programming the DSP kit, that appears to be your failure, not the failure of the technology - I presume you didn't spend long enough on it? - often such new ideas take a good deal of getting used to (been in similar situations, given up as well ).

you need mega high frequency in the DSP to get the duty cycle resolution.....its well high , seriously.

ok, granted , but that's not really what were talking about here (Pickit)....#7 ridley article is what this is about...............Dr ridley is one of the foremost smps engineers in the world.

Nigel Goodwin said:

It already is, and always has been, the clue is even in it's title - SWITCHING - digital electronics switches ON and OFF (like a SMPSU) and analogue electronics works in a linear fashion.

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Small quibble, not all digital is on/off (on/off is 'binary' digital) and not all analogue is linear (Class C amplifier). While you can control a SMPSU with digital circuits it's completely possible to use a all analog design methodology to simulate and analyze the operation of the actual switching driver and rectifier section (transformer, capacitors, inductors, power semiconductor topology).

TV Tech,
I hate to tell you. I am the person that you have cursed many times.
For years I designed the large scale ICs used in CRT monitors and TV sets.
Some I did have "analog" functions but the cost of analog ASICs is too high so most were 100% digital.
The convergence waveforms were made by "math" and came out in PWM format. Then off to drive the convergence coils or grids.
The error correction for "C" and "S" and "C balance" were created by formulas.
I have programmable H. S correction coils that are directly driven form a PWM pin on the ASIC.
Some of the error amplifiers were 100% in software.
The Rs and Cs around an error amplifier can be molded by math.
I have seen math that looks for oscillation and moves the poles around automatically. usually on motor amplifiers.
Toward the end of CRT much of the functions were digital. (I mostly worked on medical and military monitors)

Spot on mr spook.
The latest pic micro has an a to d, and also a comparator, and an rc oscillator, 2 or 3 in fact.
These are definately analogue.
I disagree with the original lecurers comments, I'm sure the lecturer is an educated fellow, however that particular comment is pants.

ronsimpson said:

TV Tech,
I hate to tell you. I am the person that you have cursed many times.
For years I designed the large scale ICs used in CRT monitors and TV sets.
Some I did have "analog" functions but the cost of analog ASICs is too high so most were 100% digital.
The convergence waveforms were made by "math" and came out in PWM format. Then off to drive the convergence coils or grids.
The error correction for "C" and "S" and "C balance" were created by formulas.
I have programmable H. S correction coils that are directly driven form a PWM pin on the ASIC.
Some of the error amplifiers were 100% in software.
The Rs and Cs around an error amplifier can be molded by math.
I have seen math that looks for oscillation and moves the poles around automatically. usually on motor amplifiers.
Toward the end of CRT much of the functions were digital. (I mostly worked on medical and military monitors)

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No worries Ron.

You are referring to Geometry correction, Vertical height correction and all that. Brilliant!!!!
I love the fact that people who do not know how to access "Service mode" can not stuff up their TV. No Pots anywhere...all Digitally done with the correct Remote. And the correct access Code.

But....you Guys never messed with SMPS in those applications. You dealt with picture, sound and the Service adjustments needed for sets....and no Pots for people to screw with.....am I correct??

I believe you regarded the SMPS as a separate Animal. That should stand on it's own two feet....and correctly so

Remember, we are seeing the last of CRT here...and even now when you are in Service Mode, you can adjust just about anything......except stuff in the PSU...separate totally from the rest of the TV .

So Ron, tvtech does not curse your work, he applaudes it. All the CRT stuff we see here is from Chinese origin...and guess what...if they could of found a cheaper way to run a SMPS...they would of tried it. No go.

You and your team did a good job of setting a nice reliable way of implementing Digital into CRT.

Thank You

tvtech