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Well, I guess that explains it.Doesn't do it for me either. I removed it cause I decided it was rubbish.
All right, that's not an SMPS, you could also use solar cells and an LED.Hero999,
I think you have to go back to Nigel's original comment:
About your comment:
Nigel is correct that there are other, albeit less practical and efficient, ways:
Motor --> Generator.
SinewaveOsc --> Amplifier --> Transformer --> rectifier and filter.
I guess you could say that the commutator in a DC motor does the "switching" but no switching is done using a Sine-wave oscillator.
I think we are splitting hairs here. Any line operated DC power supply could be considered part of a SMPS then.Yes it is, I would classify a sinewave oscillator and a transformer as an SMPS and some SMPSes indeed use sinewave oscillators e.g. a resonant converter does.
Motor --> Generator.
SinewaveOsc --> Amplifier --> Transformer --> rectifier and filter.
I guess you could say that the commutator in a DC motor does the "switching" but no switching is done using a Sine-wave oscillator.
It must have very, very low levels of short-term voltage variations such as peaks and spikes. What is important is that there are no "sudden" variations in the voltage. Whether it varies in the longer term is less important. Basically short term ripple should be as low as practically possible.
Yes it is, I would classify a sinewave oscillator and a transformer as an SMPS and some SMPSes indeed use sinewave oscillators e.g. a resonant converter does.
Come again? That's like saying an op amp uses transistors as a switch.An oscillator does indeed use transistors as a switch, they might be in a linear mode instead of a straight on/off switch,<snip>
And you would be completely wrong!
What does the 'S' stand for - SWITCHING - no switching in a sinewave, it's identical to using a standard mains transformer.
The load is only 10mA. How difficult can that be to filter?Bear in mind that 600V with a ripple of say 3V isn't going to be easy to achieve: higher voltage normally means higher ripple.
But the DC to AC conversion involves switching so it is an SMPS. It's true that the part after the inverter is no different to a normal transformer power supply but the fact that there's an inverter to convert DC to AC makes it an SMPS in my opinion.
Anyway I don't see the point about arguing about terminology as long as we agree that the only sensible way of converting a low DC voltage to a high DC voltage is to use a traditional SMPS. Old fashioned methods such as a motor generator sets and vibrators are less efficient and more noisy than modern SMPSes.
Just how do you convert the DC voltage to AC, to power the transformer without doing any switching?
But the input isn't AC it's DC remember? As you know a transformer will not work with DC so it needs to be converted to AC which involves switching as I said a couple of posts ago.
The current in the primary never reverses direction. If it did, the transistor would be cut off through part of the cycle.The transistor driving the transformer will always be turned "on". Just how turned "on" the transistor is depends on where in the sine cycle we are. The transistor will never be turned "off" or switched off in class A. The current in the transformer reverses polarity during the cycle when the magnetic flux in the transformer core collapses. That is why, with a transformer coupled class A amplifier, the voltage on the collector of the transistor can reach a theoretical value of x2 Vcc. But the key here is that the collector current NEVER drops to zero in a class A amplifier/osc unless it is being driven into clipping.
Circuit for reference:
View attachment 38400