ceramic transformers ?
 

Please see the pdf at:alt.binaries.schematics.electronic dated 5/8 8:08 PM.
Has anyone see this technology used used at RF or IF?
tnx

--

73
Hank WD5JFR

Good day

I am the one who made the post. I've been involved in rf for 30 years
and have actively followed piezotransformer technology since first
reading about them in EDN Magazine in 1999.

They are unusual beasts for sure.

The resonant frequency can be controlled by the thickness of the
material, as any piezomaterial can. For fine tuning, the size of the
electrodes on the primary side can be trimmed. Q's are not nearly as
high as quartz, so the ultimate frequency stability honors go to
quartz.

They can be useful for some rf aps, up to 3 Mhz, although the vast
majority of presently made devices operate in the 200 Khz to 40 Khz
range.

The resonant frequency does shift slightly with varying load
impedances however..

As transformers however, they excel. Conventional magnetic/copper
transformers cannot even start to deliver step up ratios anywhere near
those of PZT's.

Unknown to many is the fact that they can convert low impedance to
high impedance OR visa versa.

I have just located a source of piezotransformers that have totally
isolated primary and secondary terminals (4 terminals) instead of the
common 3 terminal types presently available.

Digi-Key sells the Panasonic units in their current catalog.

Hope this info helps.

Mebart




Mon, 09 May 2005 14:34:51 GMT, "Henry Kolesnik"
wrote:

Please see the pdf at:alt.binaries.schematics.electronic dated 5/8 8:08 PM.
Has anyone see this technology used used at RF or IF?
tnx

Good day

I am the one who made the post. I've been involved in rf for 30 years
and have actively followed piezotransformer technology since first
reading about them in EDN Magazine in 1999.

They are unusual beasts for sure.

The resonant frequency can be controlled by the thickness of the
material, as any piezomaterial can. For fine tuning, the size of the
electrodes on the primary side can be trimmed. Q's are not nearly as
high as quartz, so the ultimate frequency stability honors go to
quartz.

They can be useful for some rf aps, up to 3 Mhz, although the vast
majority of presently made devices operate in the 200 Khz to 40 Khz
range.

The resonant frequency does shift slightly with varying load
impedances however..

As transformers however, they excel. Conventional magnetic/copper
transformers cannot even start to deliver step up ratios anywhere near
those of PZT's.

Unknown to many is the fact that they can convert low impedance to
high impedance OR visa versa.

I have just located a source of piezotransformers that have totally
isolated primary and secondary terminals instead of the common 3
terminal types presently available.

Digi-Key sells the Panasonic units in their current catalog.

Hope this info helps.

Mebart




On Mon, 09 May 2005 14:34:51 GMT, "Henry Kolesnik"
wrote:

Please see the pdf at:alt.binaries.schematics.electronic dated 5/8 8:08 PM.
Has anyone see this technology used used at RF or IF?
tnx

Hey Mebart, and a good day to you too. Mehank

On a more serious note, thanks for both posts. I took a look at the
Panasonic at Digikey and it looks like they're made for ~50:1 stepup to
light up displays. http://dkc3.digikey.com/PDF/T052/1522.pdf
Have you ever checked the passband of one?

--

73
Hank WD5JFR
Mebart wrote in message ...

Good day

I am the one who made the post. I've been involved in rf for 30 years
and have actively followed piezotransformer technology since first
reading about them in EDN Magazine in 1999.

They are unusual beasts for sure.

The resonant frequency can be controlled by the thickness of the
material, as any piezomaterial can. For fine tuning, the size of the
electrodes on the primary side can be trimmed. Q's are not nearly as
high as quartz, so the ultimate frequency stability honors go to
quartz.

They can be useful for some rf aps, up to 3 Mhz, although the vast
majority of presently made devices operate in the 200 Khz to 40 Khz
range.

The resonant frequency does shift slightly with varying load
impedances however..

As transformers however, they excel. Conventional magnetic/copper
transformers cannot even start to deliver step up ratios anywhere near
those of PZT's.

Unknown to many is the fact that they can convert low impedance to
high impedance OR visa versa.

I have just located a source of piezotransformers that have totally
isolated primary and secondary terminals instead of the common 3
terminal types presently available.

Digi-Key sells the Panasonic units in their current catalog.

Hope this info helps.

Mebart




On Mon, 09 May 2005 14:34:51 GMT, "Henry Kolesnik"
wrote:

Please see the pdf at:alt.binaries.schematics.electronic dated 5/8 8:08
PM.
Has anyone see this technology used used at RF or IF?
tnx

Hi Hank,

I've never checked it specifically....and have only ballpark figures
for Q.

There is one other oddity that you probably should be aware of.... The
output voltage is not in the same phase as the input voltage. While
this isn't a great problem, do be aware that the phase difference
between the input/output also changes with temperature, and resistive
loading.

This totally precludes using them in a power oscillator circuit, which
is a bummer. They would be so simple to drive if the phase difference
was relatively constant::

I just read about a new driver chip that constantly measures and
corrects for this phase difference, and in so doing the device always
operates at peak efficiency.

There are other piezoceramics that are usable as filters and such,
goggle for them.

Regards,

Mebart

On Mon, 09 May 2005 18:56:21 GMT, "Henry Kolesnik"
wrote:

Hey Mebart, and a good day to you too. Mehank

On a more serious note, thanks for both posts. I took a look at the
Panasonic at Digikey and it looks like they're made for ~50:1 stepup to
light up displays. http://dkc3.digikey.com/PDF/T052/1522.pdf
Have you ever checked the passband of one?