High-frequency power sine wave generation

[Don Gilmore]

Guys:

I'm working on an application where I need to drive a small transformer with high frequency AC power (like around 20 kHz) at about 24 volts or so. My power comes from a 120/24 transformer. In the embedded circuit is an Atmel microcontroller which can produce a 20 kHz, 5V square wave. I need the little transformer to deliver about 4 VA.

Is there an easy way to do this? I have thought about filtering the MCU square wave to a sine and then amplifying it with an audio amp, but they are pricey and I have a lot of little transformers to drive. I have also thought about feeding to a BJT as a single-transistor amplifier.

Are there other better ways of doing this?

Don
Kansas City

 

[Jon Kirwan]

On Sun, 2 Sep 2012 10:34:08 -0700 (PDT), Don Gilmore
<eromlignod1@att.net> wrote:

Guys:

I guess capable women won't be responding.

I'm working on an application where I need to drive a small
transformer with high frequency AC power (like around 20
kHz) at about 24 volts or so. My power comes from a 120/24
transformer. In the embedded circuit is an Atmel
microcontroller which can produce a 20 kHz, 5V square wave.
I need the little transformer to deliver about 4 VA.

Is there an easy way to do this? I have thought about
filtering the MCU square wave to a sine and then amplifying
it with an audio amp, but they are pricey and I have a lot
of little transformers to drive. I have also thought about
feeding to a BJT as a single-transistor amplifier.

Are there other better ways of doing this?

You haven't actually described a way to do it yet. So it is
hard to say much about other ways.

It sounds as though you have one microcontroller with I/O
pins to spare, a lot of small transformers, a single 24VAC
transformer output at (likely) 60Hz, something that generates
DC from that and provides the small DC voltages needed by the
Atmel microcontroller, and you need to use the Atmel to chop
up the 60Hz 24VAC into 20kHz 24VAC that you will then feed to
lots (unknown number) of small transformers, each of which
need to deliver about 4 watts into a load. There is currently
no information on your 24VAC transformer and no exact count
or detailed information on the tiny transformers.

Is that about it?

Jon

 

[George Herold]

On Sep 2, 5:12 pm, Jon Kirwan <j...@infinitefactors.org> wrote:

On Sun, 2 Sep 2012 10:34:08 -0700 (PDT), Don Gilmore

eromlign...@att.net> wrote:
Guys:

I guess capable women won't be responding.

Nah, I always figure that at some point 'guys' refers to everyone in
the group,
no matter their gender. It's like 'men' in the constitution, means
both men and women.
(at least since the 19th amendment)

Hi Jon, just yanking your chain.

George H.

I'm working on an application where I need to drive a small
transformer with high frequency AC power (like around 20
kHz) at about 24 volts or so. My power comes from a 120/24
transformer. In the embedded circuit is an Atmel
microcontroller which can produce a 20 kHz, 5V square wave.
I need the little transformer to deliver about 4 VA.

Is there an easy way to do this?  I have thought about
filtering the MCU square wave to a sine and then amplifying
it with an audio amp, but they are pricey and I have a lot
of little transformers to drive. I have also thought about
feeding to a BJT as a single-transistor amplifier.

Are there other better ways of doing this?

You haven't actually described a way to do it yet. So it is
hard to say much about other ways.

It sounds as though you have one microcontroller with I/O
pins to spare, a lot of small transformers, a single 24VAC
transformer output at (likely) 60Hz, something that generates
DC from that and provides the small DC voltages needed by the
Atmel microcontroller, and you need to use the Atmel to chop
up the 60Hz 24VAC into 20kHz 24VAC that you will then feed to
lots (unknown number) of small transformers, each of which
need to deliver about 4 watts into a load. There is currently
no information on your 24VAC transformer and no exact count
or detailed information on the tiny transformers.

Is that about it?

Jon

 

On Sunday, September 2, 2012 2:54:34 PM UTC-7, George Herold wrote:

On Sep 2, 5:12 pm, Jon Kirwan <j...@infinitefactors.org> wrote:

On Sun, 2 Sep 2012 10:34:08 -0700 (PDT), Don Gilmore



eromlign...@att.net> wrote:

Guys:



I guess capable women won't be responding.



Nah, I always figure that at some point 'guys' refers to everyone in

the group,

no matter their gender. It's like 'men' in the constitution, means

both men and women.

(at least since the 19th amendment)



Hi Jon, just yanking your chain.



George H.

Just like "There's a man-eating tiger in the street!" and so women should feel just fine wandering out there... =)