
Originally Posted by
Crazymechanic
thanks for the replies Harold and JonG,
well yes I know that a transformer needs a time varying in amplitude and /or polarity signal for induction to happen and any transfer of energy between the coils to be possible.
I'm also aware that transistors in most of the SMPS do this , they chop the incomming DC so that it could be used to induce secondary current.
I was just wondering about some other possible way to achieve this assuming we have a dc supply, and we need a transformer to isolate/step down or up voltage/ current.
Also from a pure point of durability , an old spark gap may wear down much faster and be much les safe yet it deals just fine with overcurrents or current lagging or any other factor that comes in mind could blow up a good smps.
Also the fact that whenever a switch (semiconductor) is closed in series with the primary it has the full PD across that switch , I was thinking maybe there is a way in which to make the electric field due work instead of physical switches directing current paths.
I;m not saying this could work just for an example , imagine this varyable cap I was talking about has a special dielectric material which drops in dielectric constant whenever a certain level of voltage is reached across the capacitor plates, like the cap charges charges and then the constant drops and so drops the capacitance and some of the charge that went into the capacitor now has to flow back , but then after some moment the dielectric goes back to its initial constant and so the capacitance increases and the charge runs towards the capacitor once again.
In this sense this device would work similar to a spark gap , as whenever the voltage on the contacts reaches a certain value a arc forms and current travels for a brief moment of time until the voltage drops and the arc cannot be sustained anymore.
What do you think about this?