G
geoff smith
- Jan 1, 1970
- 0
Can anyone suggest an interesting use for microwave oven transformers .
Regards Geoff.
Regards Geoff.
Can anyone suggest an interesting use for microwave oven transformers .
Regards Geoff.
geoff smith said:Can anyone suggest an interesting use for microwave oven transformers .
Regards Geoff.
geoff smith said:Can anyone suggest an interesting use for microwave oven transformers .
Regards Geoff.
geoff said:Can anyone suggest an interesting use for microwave oven transformers .
geoff smith said:Can anyone suggest an interesting use for microwave oven transformers .
Regards Geoff.
geoff smith" ([email protected]) said:Can anyone suggest an interesting use for microwave oven transformers .
If you switch around the primary and secondary,Charles said:Ham radio enthusiasts use them in power supplies for high-power vacuum tube
transmitters.
Although they're not actually terribly good for this use, as their designCharles said:Ham radio enthusiasts use them in power supplies for high-power vacuum
tube transmitters.
Core saturation blows fuses. Don't think that's the mechanism goingArfa said:Although they're not actually terribly good for this use, as their design
makes them self-limiting by way of core saturation, as I understand it.
Arfa
That's probably right. I was going to use one for obtaining the HT supplymike said:Core saturation blows fuses. Don't think that's the mechanism going on
here. But there are magnetic shunts that increase the leakage inductance
and limit current. Take out the shunts for non-limited
applications.
mike
If you switch around the primary and secondary,
you get a nice low voltage high current transformer.
And suddenly its not dangerous anymore.
Although they're not actually terribly good for this use, as their
design makes them self-limiting by way of core saturation, as I
understand it.
Arfa
That's probably right. I was going to use one for obtaining the HT supply
for a 3CX400 I think it was, that I used in a grounded grid linear for 2
metres some years back, but in the end I didn't after reading a very
detailed article on why they were no good for the job. As I say, it's been
some years now, and the presence of magnetic shunts may well be the main
reason quoted - I don't remember for sure. But something about the core size
or it's characteristics or something seems to keep coming to mind as being
the quoted reason for the secondary regulation being very poor when the
current demand is variable, as it would be when powering an amplifier being
driven with an SSB exciter, as opposed to it's designed use of providing the
HT for a magnetron power oscillator, whose current demand will be pretty
much constant. Maybe that situation has changed now, with the recent
introduction of true power-controlled microwave ovens, rather than the
former on-off switching control to produce an average cooking power ?? Maybe
the trannies from this generation of ovens are better suited to
'alternative' uses ?
Arfa
Jim Yanik said:Uh,the microwave magnetron is a vacuum TUBE just like any RF transmitting
tube,just for a different frequency.
I see no reason for having the xfmr core saturate for a MW oven.
--
Jim Yanik
jyanik
at
kua.net
Don't get too excited about the magnetic shunts.Arfa said:Agreed, but the point I was making Jim, is that a microwave oven is a high
power CW oscillator. Most required ham radio use is for high power tube
linears which are most likely to be used for SSB transmissions, where the
current demand will swing from maybe as little as zero, to some maximum,
depending on the class and exact configuration of the amp. There is
something about the construction of the microwave oven transformer core -
and it seems to be the consensus that this is the presence of magnetic
shunts rather than any core saturation - that makes them inherently self
current limiting, thus keeping the magnetron operating in spec.
I would accept though that there should be no problem using one of these for
an RF amp intended for FM or any other constant carrier amplitude mode,
where the current demand on the power supply, will be largely constant.
Arfa