Sine Wave Amplification
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Posts: 46,084
I have a project thhat will require the amplification of a sine wave
from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
need to drive a load at about 0.5 amp. I'm using the Stamp to
manipulate phase shifts, and have found a lot of information relating
to amplifying the stamp output power to drive selonids and motors,
but nothing on amplifying a sine wave. If anyone could steer me to
some simple ciruitry or reference data I would greatly appreciate it.
Thanks in advance Larry.
from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
need to drive a load at about 0.5 amp. I'm using the Stamp to
manipulate phase shifts, and have found a lot of information relating
to amplifying the stamp output power to drive selonids and motors,
but nothing on amplifying a sine wave. If anyone could steer me to
some simple ciruitry or reference data I would greatly appreciate it.
Thanks in advance Larry.
Comments
writes:
> I have a project thhat will require the amplification of a sine wave
> from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
> need to drive a load at about 0.5 amp. I'm using the Stamp to
> manipulate phase shifts, and have found a lot of information relating
> to amplifying the stamp output power to drive selonids and motors,
> but nothing on amplifying a sine wave. If anyone could steer me to
> some simple ciruitry or reference data I would greatly appreciate it.
> Thanks in advance Larry.
>
First thought is the Stamp is not suited to amplify a sine-wave.
What is the source of the 5v RMS>
The easiest thing I can think of to turn 5v rms into 120 v rms is a step-up
transformer. A general consideration using transformers.......if you step the
voltage up, the output current will be less that the input current and visa
versa.
[noparse][[/noparse]Non-text portions of this message have been removed]
If you have a 0.5 amp load at 120 volts AC, that's
(Power = Current * Voltage, == 60 watts). At
5 volts, that would be (Current = Power/Voltage)
== 12 AMPS. This is true because the Power
value remains constant when doing voltage
step-up.
5 Volts at 12 amps has left the comfortable Stamp
zone (5 to 12 volts at 20 to 100 mA typical, 1 amp max).
We're now in car-battery/starting motor land.
(BTW, at 12 volts we're talking 5 amps).
Of course, this can be done. You'll need some
serious current switching hardware, however.
--- In basicstamps@yahoogroups.com, "larryfreeport" <lhalesi@d...>
wrote:
> I have a project thhat will require the amplification of a sine
wave
> from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
> need to drive a load at about 0.5 amp. I'm using the Stamp to
> manipulate phase shifts, and have found a lot of information
relating
> to amplifying the stamp output power to drive selonids and motors,
> but nothing on amplifying a sine wave. If anyone could steer me to
> some simple ciruitry or reference data I would greatly appreciate
it.
> Thanks in advance Larry.
level sine wave input and amplify it to the level you require. Since you
are working only with 60 hz, you could amplify the signal to gain power and
then couple it to the output via a transformer to boost voltage. (when you
boost voltage, more power is required from the input). Consider power lost
in the transformer as heat, and phase shift in the amplifier and transformer
when applying the original sine wave. You also would want to filter the
original sine wave to clean it up from the stamp before applying it to the
amplifier input. If you want to do this project simply, use a bass
amplifier sold for car audio applications, match the output to a
transformer, and boost the voltage level in the transformer. The gain
control on the amp will set the output level. Again, consider and measure
the phase shift through this arrangement. Check the ARRL amateur radio
handbook for information on matching and filtering and transformer formulae.
Jim
http://www.geocities.com/jimforkin2003/
Original Message
From: smartdim@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=AWPg6G470VVJ8VhP1zhVy5BmaA6nHhgICyk9pjZs_0C1hiirGEkFql59ukLOxBFB2YvIuAGL]smartdim@a...[/url
Sent: Thursday, June 05, 2003 6:25 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave Amplification
In a message dated 6/5/2003 3:09:38 PM Pacific Daylight Time,
lhalesi@d...
writes:
> I have a project thhat will require the amplification of a sine wave
> from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
> need to drive a load at about 0.5 amp. I'm using the Stamp to
> manipulate phase shifts, and have found a lot of information relating
> to amplifying the stamp output power to drive selonids and motors,
> but nothing on amplifying a sine wave. If anyone could steer me to
> some simple ciruitry or reference data I would greatly appreciate it.
> Thanks in advance Larry.
>
First thought is the Stamp is not suited to amplify a sine-wave.
What is the source of the 5v RMS>
The easiest thing I can think of to turn 5v rms into 120 v rms is a step-up
transformer. A general consideration using transformers.......if you step
the
voltage up, the output current will be less that the input current and visa
versa.
[noparse][[/noparse]Non-text portions of this message have been removed]
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
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Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Wal-Mart and save the headaches.
Original Message
> Yes, this application needs a step-up transformer.
> If you have a 0.5 amp load at 120 volts AC, that's
> (Power = Current * Voltage, == 60 watts). At
> 5 volts, that would be (Current = Power/Voltage)
> == 12 AMPS. This is true because the Power
> value remains constant when doing voltage
> step-up.
>
> 5 Volts at 12 amps has left the comfortable Stamp
> zone (5 to 12 volts at 20 to 100 mA typical, 1 amp max).
> We're now in car-battery/starting motor land.
> (BTW, at 12 volts we're talking 5 amps).
>
> Of course, this can be done. You'll need some
> serious current switching hardware, however.
> > I have a project thhat will require the amplification of a sine
> wave
> > from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
> > need to drive a load at about 0.5 amp. I'm using the Stamp to
> > manipulate phase shifts, and have found a lot of information
> relating
> > to amplifying the stamp output power to drive selonids and motors,
> > but nothing on amplifying a sine wave. If anyone could steer me to
> > some simple ciruitry or reference data I would greatly appreciate
> it.
Thanks you have given me a good start. Actually I am trying to build
a piece of test equipment. Looking closer at the equipment that will
hook up to my test set, I will only need to drive about 2 or 3
milliamps, not 500. Thanks, Larry
--- In basicstamps@yahoogroups.com, "Jim Forkin" <jjf@p...> wrote:
> What you need is a class A or B linear amplifier which will take
your low level sine wave input and amplify it to the level you
require. Since you are working only with 60 hz, you could amplify the
signal to gain power and then couple it to the output via a
transformer to boost voltage. (when you boost voltage, more power is
required from the input). Consider power lost in the transformer as
heat, and phase shift in the amplifier and transformer when applying
the original sine wave. You also would want to filter the original
sine wave to clean it up from the stamp before applying it to the
amplifier input. If you want to do this project simply, use a bass
amplifier sold for car audio applications, match the output to a
transformer, and boost the voltage level in the transformer. The gain
control on the amp will set the output level. Again, consider and
measure the phase shift through this arrangement. Check the ARRL
amateur radio handbook for information on matching and filtering and
transformer formulae.
>
> Jim
> http://www.geocities.com/jimforkin2003/
>
>
>
Original Message
> From: smartdim@a... [noparse][[/noparse]mailto:smartdim@a...]
> Sent: Thursday, June 05, 2003 6:25 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave Amplification
>
>
> In a message dated 6/5/2003 3:09:38 PM Pacific Daylight Time,
> lhalesi@d...
> writes:
>
> > I have a project thhat will require the amplification of a sine
wave
> > from about 5 VRMS (60hz) to about 120 VRMS (60hz). The output will
> > need to drive a load at about 0.5 amp. I'm using the Stamp to
> > manipulate phase shifts, and have found a lot of information
relating
> > to amplifying the stamp output power to drive selonids and motors,
> > but nothing on amplifying a sine wave. If anyone could steer me to
> > some simple ciruitry or reference data I would greatly appreciate
it.
> > Thanks in advance Larry.
> >
>
> First thought is the Stamp is not suited to amplify a sine-wave.
> What is the source of the 5v RMS>
>
> The easiest thing I can think of to turn 5v rms into 120 v rms is a
step-up
> transformer. A general consideration using transformers.......if
you step
> the
> voltage up, the output current will be less that the input current
and visa
> versa.
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
I think you can accomplish your task with a simple
audio amplifier (class A) tweeked for high voltage,
low frequency operation. Something as simple as a
power FET (~400 V DS @ 125W) plus an appropriate
current sink (resistor of about 10 watts) with an
op-amp driving the FET's gate and setup for
appropriate gain would work. Of course, you're dealing
with lethal voltages and any oscillations would cook
your circuit, but at 60Hz, everything could be "rolled
off" easily. Phase shift and STAMP control are a
little more involved. Consider an A/D for accuracy, or
basic R/C for simplicity. Again, because of the low
frequency, you shouldn't have real problems. Always be
careful.
Dr. Diode
--- larryfreeport <lhalesi@d...> wrote:
> June 7, 2003
>
> Thanks you have given me a good start. Actually I am
> trying to build
> a piece of test equipment. Looking closer at the
> equipment that will
> hook up to my test set, I will only need to drive
> about 2 or 3
> milliamps, not 500. Thanks, Larry
>
>
>
> --- In basicstamps@yahoogroups.com, "Jim Forkin"
> <jjf@p...> wrote:
> > What you need is a class A or B linear amplifier
> which will take
> your low level sine wave input and amplify it to the
> level you
> require. Since you are working only with 60 hz, you
> could amplify the
> signal to gain power and then couple it to the
> output via a
> transformer to boost voltage. (when you boost
> voltage, more power is
> required from the input). Consider power lost in
> the transformer as
> heat, and phase shift in the amplifier and
> transformer when applying
> the original sine wave. You also would want to
> filter the original
> sine wave to clean it up from the stamp before
> applying it to the
> amplifier input. If you want to do this project
> simply, use a bass
> amplifier sold for car audio applications, match the
> output to a
> transformer, and boost the voltage level in the
> transformer. The gain
> control on the amp will set the output level.
> Again, consider and
> measure the phase shift through this arrangement.
> Check the ARRL
> amateur radio handbook for information on matching
> and filtering and
> transformer formulae.
> >
> > Jim
> > http://www.geocities.com/jimforkin2003/
> >
> >
> >
Original Message
> > From: smartdim@a... [noparse][[/noparse]mailto:smartdim@a...]
> > Sent: Thursday, June 05, 2003 6:25 PM
> > To: basicstamps@yahoogroups.com
> > Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave Amplification
> >
> >
> > In a message dated 6/5/2003 3:09:38 PM Pacific
> Daylight Time,
> > lhalesi@d...
> > writes:
> >
> > > I have a project thhat will require the
> amplification of a sine
> wave
> > > from about 5 VRMS (60hz) to about 120 VRMS
> (60hz). The output will
> > > need to drive a load at about 0.5 amp. I'm using
> the Stamp to
> > > manipulate phase shifts, and have found a lot of
> information
> relating
> > > to amplifying the stamp output power to drive
> selonids and motors,
> > > but nothing on amplifying a sine wave. If anyone
> could steer me to
> > > some simple ciruitry or reference data I would
> greatly appreciate
> it.
> > > Thanks in advance Larry.
> > >
> >
> > First thought is the Stamp is not suited to
> amplify a sine-wave.
> > What is the source of the 5v RMS>
> >
> > The easiest thing I can think of to turn 5v rms
> into 120 v rms is a
> step-up
> > transformer. A general consideration using
> transformers.......if
> you step
> > the
> > voltage up, the output current will be less that
> the input current
> and visa
> > versa.
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been
> removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
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close to what I had originally hoped to do. Using a demo
version of MicroSim (circuit analysis software) I modeled
a simple circuit consisting of a sine wave source, a few
resistors and a power FET. The problem I ran into was that
the output was distorted (flat spots around the zero
crossings). That stumped me (I am pretty much a beginner
when it comes to designing electronic circuitry). Is there
a simple way to filter out the flat spots and get a purer
sinewave out? Larry
Original Message
From: PH [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=dTT4Yp4DaLlaCCnVKA1T3F-cB-O2TTAo_4ub33mZW_66d1aT-obpMVxS4_mXxFvdYpjipnddlGNJhj3kfv0]drdiode2002@y...[/url
Sent: Tuesday, June 10, 2003 7:01 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Sine Wave Amplification
Hi Larry,
I think you can accomplish your task with a simple
audio amplifier (class A) tweeked for high voltage,
low frequency operation. Something as simple as a
power FET (~400 V DS @ 125W) plus an appropriate
current sink (resistor of about 10 watts) with an
op-amp driving the FET's gate and setup for
appropriate gain would work. Of course, you're dealing
with lethal voltages and any oscillations would cook
your circuit, but at 60Hz, everything could be "rolled
off" easily. Phase shift and STAMP control are a
little more involved. Consider an A/D for accuracy, or
basic R/C for simplicity. Again, because of the low
frequency, you shouldn't have real problems. Always be
careful.
Dr. Diode
--- larryfreeport <lhalesi@d...> wrote:
> June 7, 2003
>
> Thanks you have given me a good start. Actually I am
> trying to build
> a piece of test equipment. Looking closer at the
> equipment that will
> hook up to my test set, I will only need to drive
> about 2 or 3
> milliamps, not 500. Thanks, Larry
>
>
>
> --- In basicstamps@yahoogroups.com, "Jim Forkin"
> <jjf@p...> wrote:
> > What you need is a class A or B linear amplifier
> which will take
> your low level sine wave input and amplify it to the
> level you
> require. Since you are working only with 60 hz, you
> could amplify the
> signal to gain power and then couple it to the
> output via a
> transformer to boost voltage. (when you boost
> voltage, more power is
> required from the input). Consider power lost in
> the transformer as
> heat, and phase shift in the amplifier and
> transformer when applying
> the original sine wave. You also would want to
> filter the original
> sine wave to clean it up from the stamp before
> applying it to the
> amplifier input. If you want to do this project
> simply, use a bass
> amplifier sold for car audio applications, match the
> output to a
> transformer, and boost the voltage level in the
> transformer. The gain
> control on the amp will set the output level.
> Again, consider and
> measure the phase shift through this arrangement.
> Check the ARRL
> amateur radio handbook for information on matching
> and filtering and
> transformer formulae.
> >
> > Jim
> > http://www.geocities.com/jimforkin2003/
> >
> >
> >
Original Message
> > From: smartdim@a... [noparse][[/noparse]mailto:smartdim@a...]
> > Sent: Thursday, June 05, 2003 6:25 PM
> > To: basicstamps@yahoogroups.com
> > Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave Amplification
> >
> >
> > In a message dated 6/5/2003 3:09:38 PM Pacific
> Daylight Time,
> > lhalesi@d...
> > writes:
> >
> > > I have a project thhat will require the
> amplification of a sine
> wave
> > > from about 5 VRMS (60hz) to about 120 VRMS
> (60hz). The output will
> > > need to drive a load at about 0.5 amp. I'm using
> the Stamp to
> > > manipulate phase shifts, and have found a lot of
> information
> relating
> > > to amplifying the stamp output power to drive
> selonids and motors,
> > > but nothing on amplifying a sine wave. If anyone
> could steer me to
> > > some simple ciruitry or reference data I would
> greatly appreciate
> it.
> > > Thanks in advance Larry.
> > >
> >
> > First thought is the Stamp is not suited to
> amplify a sine-wave.
> > What is the source of the 5v RMS>
> >
> > The easiest thing I can think of to turn 5v rms
> into 120 v rms is a
> step-up
> > transformer. A general consideration using
> transformers.......if
> you step
> > the
> > voltage up, the output current will be less that
> the input current
> and visa
> > versa.
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been
> removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
__________________________________
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To UNSUBSCRIBE, just send mail to:
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suggestion, use a 6.3volt, 120 volt primary transformer backwards to boost
your voltage up to the required level. (the transformer will also get rid
of some distortion as it's frequency response off 60 hz drops rapidly.
jim
http://www.geocities.com/jimforkin2003/
Original Message
From: Alesi, Larry (LH) [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=5nL-F6xs3ETvBh0wDsb1yv0OwOemaANh-J1IX2X9H4oe0RMnM-luCTvQsk8wfsJI0nVmc_JdGCc]lhalesi@d...[/url
Sent: Wednesday, June 11, 2003 12:30 PM
To: 'basicstamps@yahoogroups.com'
Subject: [noparse][[/noparse]basicstamps] Re: Sine Wave Amplification
Hello Dr. Diode - Actually what you are describing is very
close to what I had originally hoped to do. Using a demo
version of MicroSim (circuit analysis software) I modeled
a simple circuit consisting of a sine wave source, a few
resistors and a power FET. The problem I ran into was that
the output was distorted (flat spots around the zero
crossings). That stumped me (I am pretty much a beginner
when it comes to designing electronic circuitry). Is there
a simple way to filter out the flat spots and get a purer
sinewave out? Larry
Original Message
From: PH [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=PDrhG9b8Ts3vblxufQ10oQ1yNWP309vBTDvYiJBoZe0hatKQUrhzL52PrOk3QcPw6NFV2VOKXXRAWUI-kGJS6Q]drdiode2002@y...[/url
Sent: Tuesday, June 10, 2003 7:01 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Re: Sine Wave Amplification
Hi Larry,
I think you can accomplish your task with a simple
audio amplifier (class A) tweeked for high voltage,
low frequency operation. Something as simple as a
power FET (~400 V DS @ 125W) plus an appropriate
current sink (resistor of about 10 watts) with an
op-amp driving the FET's gate and setup for
appropriate gain would work. Of course, you're dealing
with lethal voltages and any oscillations would cook
your circuit, but at 60Hz, everything could be "rolled
off" easily. Phase shift and STAMP control are a
little more involved. Consider an A/D for accuracy, or
basic R/C for simplicity. Again, because of the low
frequency, you shouldn't have real problems. Always be
careful.
Dr. Diode
--- larryfreeport <lhalesi@d...> wrote:
> June 7, 2003
>
> Thanks you have given me a good start. Actually I am
> trying to build
> a piece of test equipment. Looking closer at the
> equipment that will
> hook up to my test set, I will only need to drive
> about 2 or 3
> milliamps, not 500. Thanks, Larry
>
>
>
> --- In basicstamps@yahoogroups.com, "Jim Forkin"
> <jjf@p...> wrote:
> > What you need is a class A or B linear amplifier
> which will take
> your low level sine wave input and amplify it to the
> level you
> require. Since you are working only with 60 hz, you
> could amplify the
> signal to gain power and then couple it to the
> output via a
> transformer to boost voltage. (when you boost
> voltage, more power is
> required from the input). Consider power lost in
> the transformer as
> heat, and phase shift in the amplifier and
> transformer when applying
> the original sine wave. You also would want to
> filter the original
> sine wave to clean it up from the stamp before
> applying it to the
> amplifier input. If you want to do this project
> simply, use a bass
> amplifier sold for car audio applications, match the
> output to a
> transformer, and boost the voltage level in the
> transformer. The gain
> control on the amp will set the output level.
> Again, consider and
> measure the phase shift through this arrangement.
> Check the ARRL
> amateur radio handbook for information on matching
> and filtering and
> transformer formulae.
> >
> > Jim
> > http://www.geocities.com/jimforkin2003/
> >
> >
> >
Original Message
> > From: smartdim@a... [noparse][[/noparse]mailto:smartdim@a...]
> > Sent: Thursday, June 05, 2003 6:25 PM
> > To: basicstamps@yahoogroups.com
> > Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave Amplification
> >
> >
> > In a message dated 6/5/2003 3:09:38 PM Pacific
> Daylight Time,
> > lhalesi@d...
> > writes:
> >
> > > I have a project thhat will require the
> amplification of a sine
> wave
> > > from about 5 VRMS (60hz) to about 120 VRMS
> (60hz). The output will
> > > need to drive a load at about 0.5 amp. I'm using
> the Stamp to
> > > manipulate phase shifts, and have found a lot of
> information
> relating
> > > to amplifying the stamp output power to drive
> selonids and motors,
> > > but nothing on amplifying a sine wave. If anyone
> could steer me to
> > > some simple ciruitry or reference data I would
> greatly appreciate
> it.
> > > Thanks in advance Larry.
> > >
> >
> > First thought is the Stamp is not suited to
> amplify a sine-wave.
> > What is the source of the 5v RMS>
> >
> > The easiest thing I can think of to turn 5v rms
> into 120 v rms is a
> step-up
> > transformer. A general consideration using
> transformers.......if
> you step
> > the
> > voltage up, the output current will be less that
> the input current
> and visa
> > versa.
> >
> >
> > [noparse][[/noparse]Non-text portions of this message have been
> removed]
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the
> Subject and
> > Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
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Without seeing your MicroSim design, it's hard to
imagine what caused your "clipping." Clipping is when
the signal squares off at the top or bottom of the
sign wave. If you're describing a "notch - flat spot"
in the middle of the sign wave, then you're describing
cross-over distortion. Clipping originates from the
rail voltages being too low for the desired output
signal. Cross-over distortion originates from two
devices not conducting when the signal passes zero
volts. This shuld not be the case with a single device
(class-A) and a resistor current source. Either way,
be sure your sign wave signal source is clean. Even if
you use a transfomer (6.3VAC|120VAC), your signal must
be decent.
The op-amp I mentioned, if used and designed properly,
would basically eliminate the cross-over distortion
and would closely follow your input signal regardless
of load. The clipping I mentioned is based on power
supply, so plan accordingly. Do some amplifier
research and maybe look into some piezo drivers as
they deal with high voltages at low currents.
Cheers,
Dr. Diode
--- "Alesi, Larry (LH)" <lhalesi@d...> wrote:
> Hello Dr. Diode - Actually what you are describing
> is very
> close to what I had originally hoped to do. Using a
> demo
> version of MicroSim (circuit analysis software) I
> modeled
> a simple circuit consisting of a sine wave source, a
> few
> resistors and a power FET. The problem I ran into
> was that
> the output was distorted (flat spots around the zero
>
> crossings). That stumped me (I am pretty much a
> beginner
> when it comes to designing electronic circuitry). Is
> there
> a simple way to filter out the flat spots and get a
> purer
> sinewave out? Larry
>
>
Original Message
> From: PH [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=OOYs3SSMP67zlRQyZMxdyklRKuHlkN93GBJM_PyH9qykqXtMCGlm2GaYy-tgbqDC7B5j-wFsdEoRjwaH2k0]drdiode2002@y...[/url
> Sent: Tuesday, June 10, 2003 7:01 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Re: Sine Wave
> Amplification
>
>
> Hi Larry,
>
> I think you can accomplish your task with a simple
> audio amplifier (class A) tweeked for high voltage,
> low frequency operation. Something as simple as a
> power FET (~400 V DS @ 125W) plus an appropriate
> current sink (resistor of about 10 watts) with an
> op-amp driving the FET's gate and setup for
> appropriate gain would work. Of course, you're
> dealing
> with lethal voltages and any oscillations would cook
> your circuit, but at 60Hz, everything could be
> "rolled
> off" easily. Phase shift and STAMP control are a
> little more involved. Consider an A/D for accuracy,
> or
> basic R/C for simplicity. Again, because of the low
> frequency, you shouldn't have real problems. Always
> be
> careful.
>
> Dr. Diode
> --- larryfreeport <lhalesi@d...> wrote:
> > June 7, 2003
> >
> > Thanks you have given me a good start. Actually I
> am
> > trying to build
> > a piece of test equipment. Looking closer at the
> > equipment that will
> > hook up to my test set, I will only need to drive
> > about 2 or 3
> > milliamps, not 500. Thanks, Larry
> >
> >
> >
> > --- In basicstamps@yahoogroups.com, "Jim Forkin"
> > <jjf@p...> wrote:
> > > What you need is a class A or B linear amplifier
> > which will take
> > your low level sine wave input and amplify it to
> the
> > level you
> > require. Since you are working only with 60 hz,
> you
> > could amplify the
> > signal to gain power and then couple it to the
> > output via a
> > transformer to boost voltage. (when you boost
> > voltage, more power is
> > required from the input). Consider power lost in
> > the transformer as
> > heat, and phase shift in the amplifier and
> > transformer when applying
> > the original sine wave. You also would want to
> > filter the original
> > sine wave to clean it up from the stamp before
> > applying it to the
> > amplifier input. If you want to do this project
> > simply, use a bass
> > amplifier sold for car audio applications, match
> the
> > output to a
> > transformer, and boost the voltage level in the
> > transformer. The gain
> > control on the amp will set the output level.
> > Again, consider and
> > measure the phase shift through this arrangement.
> > Check the ARRL
> > amateur radio handbook for information on matching
> > and filtering and
> > transformer formulae.
> > >
> > > Jim
> > > http://www.geocities.com/jimforkin2003/
> > >
> > >
> > >
Original Message
> > > From: smartdim@a... [noparse][[/noparse]mailto:smartdim@a...]
> > > Sent: Thursday, June 05, 2003 6:25 PM
> > > To: basicstamps@yahoogroups.com
> > > Subject: Re: [noparse][[/noparse]basicstamps] Sine Wave
> Amplification
> > >
> > >
> > > In a message dated 6/5/2003 3:09:38 PM Pacific
> > Daylight Time,
> > > lhalesi@d...
> > > writes:
> > >
> > > > I have a project thhat will require the
> > amplification of a sine
> > wave
> > > > from about 5 VRMS (60hz) to about 120 VRMS
> > (60hz). The output will
> > > > need to drive a load at about 0.5 amp. I'm
> using
> > the Stamp to
> > > > manipulate phase shifts, and have found a lot
> of
> > information
> > relating
> > > > to amplifying the stamp output power to drive
> > selonids and motors,
> > > > but nothing on amplifying a sine wave. If
> anyone
> > could steer me to
> > > > some simple ciruitry or reference data I would
> > greatly appreciate
> > it.
> > > > Thanks in advance Larry.
> > > >
> > >
> > > First thought is the Stamp is not suited to
> > amplify a sine-wave.
> > > What is the source of the 5v RMS>
> > >
> > > The easiest thing I can think of to turn 5v rms
> > into 120 v rms is a
> > step-up
> > > transformer. A general consideration using
> > transformers.......if
> > you step
> > > the
> > > voltage up, the output current will be less that
> > the input current
> > and visa
> > > versa.
> > >
> > >
> > > [noparse][[/noparse]Non-text portions of this message have been
> > removed]
> > >
> > >
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>
>
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