Very low noise ~1000VDC power supply.

[Hero999]

I can see your points, I just still consider it to be switching even if the current doesn't drop to zero.

If I connect a resistor in parallel with a switch and connect a light bulb in series, the brightness of the light-bulb will still change as I flip the switch.

I still consider class A to be a type of switching: the impedance of the transistor is dynamically changing between one value and another which in my view is switching.

As I said before I don't see the point in arguing about terms.

 

[kchriste]

The current in the primary never reverses direction. If it did, the transistor would be cut off through part of the cycle.

EDIT: Ah I see your point. The polarity of the voltage across the primary reverses. I confused the two. OOps.

 

[Nigel Goodwin]

I can see your points, I just still consider it to be switching even if the current doesn't drop to zero.

Dropping to zero has nothing to do with it, and in the example we're talking about would indeed drop to zero, and beyond.

If I connect a resistor in parallel with a switch and connect a light bulb in series, the brightness of the light-bulb will still change as I flip the switch.

I still consider class A to be a type of switching: the impedance of the transistor is dynamically changing between one value and another which in my view is switching.

As I said before I don't see the point in arguing about terms.

It's not a question of 'arguing' it's a question of posting correct information - the fact that you have a different interpretation of a word to everyone else in the world doesn't mean you should try and convince everyone else to your incorrect point of view.

Switching is either ON or OFF - nothing else, nothing in between.

Your lightbulb example is fine, flicking the switch ON and OFF is 'switching' (the clue is in the name of the component ), varying the resistor (using a potentiometer) wouldn't be switching. That's the difference we're talking about in this thread.

 

[Roff]

Dropping to zero has nothing to do with it, and in the example we're talking about would indeed drop to zero, and beyond.



It's not a question of 'arguing' it's a question of posting correct information - the fact that you have a different interpretation of a word to everyone else in the world doesn't mean you should try and convince everyone else to your incorrect point of view.

Switching is either ON or OFF - nothing else, nothing in between.

Your lightbulb example is fine, flicking the switch ON and OFF is 'switching' (the clue is in the name of the component ), varying the resistor (using a potentiometer) wouldn't be switching. That's the difference we're talking about in this thread.

By his definition, there are no active analog circuits. An op amp is a switcher.

 

[Hero999]

All right, I've thought about this more and I've realised that I was wrong.

A switch is really either on or off so a class A or A-B amplifier is not a switcher so a transformer powered by a class A-B amplifier is not an SMPS.

Sorry for taking so long to realise this.