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Using consumer-grade power amp as Power opamp

Started by Dave M May 15, 2017
Has anyone used any of the consumer-grade audio power amps such as the 
LM1825, TDA2030, or TDS7297  as a basic DC power opamp?
Any reason they shouldn't be used as power supply regulators, TEC 
controllers, etc?

Dave M 


On 5/15/2017 7:49 AM, Dave M wrote:
> Has anyone used any of the consumer-grade audio power amps such as the > LM1825, TDA2030, or TDS7297 as a basic DC power opamp? > Any reason they shouldn't be used as power supply regulators, TEC > controllers, etc?
Consider how they handle (highly) reactive loads?
On Monday, May 15, 2017 at 10:49:56 AM UTC-4, Dave M wrote:
> Has anyone used any of the consumer-grade audio power amps such as the > LM1825, TDA2030, or TDS7297 as a basic DC power opamp? > Any reason they shouldn't be used as power supply regulators, TEC > controllers, etc? > > Dave M
Only the TDA2030 comes up in a search (as obsolete) check your part numbers. I'm guessing the DC performance is not as good as it could be. Lots of DC offset perhaps. George H.
On a sunny day (Mon, 15 May 2017 09:49:45 -0500) it happened "Dave M"
<dgminala@mediacombb.net> wrote in
<J8SdnQ82rpuXXYTEnZ2dnUU7-KvNnZ2d@giganews.com>:

>Has anyone used any of the consumer-grade audio power amps such as the >LM1825, TDA2030, or TDS7297 as a basic DC power opamp? >Any reason they shouldn't be used as power supply regulators, TEC >controllers, etc? > >Dave M
I have an audio amp with tda7294. 100V - 100W DMOS AUDIO AMPLIFIER WITH MUTE/ST-BY All works, but not used or DC, these amps have a bootstrap cap from the output. http://panteltje.com/panteltje/amplifier/index.html It has no problem with reactive loads, been using it to drive a 24 to 230 V transformer in reverse to drive my cryocooler at 60 Hz (we have 50 Hz here). The fact that it is still in one piece proves it is a great chip... And it does not even need a Boucherot network: https://en.wikipedia.org/wiki/Boucherot_cell I have been told other version of TDA.. whatever are NOT stable without that network, so this seems to be unique to this DMOS chip.
On Mon, 15 May 2017 09:49:45 -0500, "Dave M" <dgminala@mediacombb.net>
wrote:

>Has anyone used any of the consumer-grade audio power amps such as the >LM1825, TDA2030, or TDS7297 as a basic DC power opamp? >Any reason they shouldn't be used as power supply regulators, TEC >controllers, etc? > >Dave M >
I like TCA0372, which is a real opamp. With the right caps, it's c-load stable, so you can use it in programmable power supplies and such. And it's cheap! -- John Larkin Highland Technology, Inc lunatic fringe electronics
On Mon, 15 May 2017 09:49:45 -0500, "Dave M" <dgminala@mediacombb.net>
wrote:

>Has anyone used any of the consumer-grade audio power amps such as the >LM1825, TDA2030, or TDS7297 as a basic DC power opamp? >Any reason they shouldn't be used as power supply regulators, TEC >controllers, etc? > >Dave M >
A number of those audio power amplifiers aren't designed for direct coupling, so some fudge will be necessary to get them working... so that, in conjunction with an OpAmp, they can oscillate >:-} ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | STV, Queen Creek, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Thinking outside the box... producing elegant solutions. "It is not in doing what you like, but in liking what you do that is the secret of happiness." -James Barrie
On a sunny day (Mon, 15 May 2017 09:03:06 -0700) it happened Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in
<i6kjhc5hj95827e6d6q0pcjv0gj64h8cd4@4ax.com>:

>On Mon, 15 May 2017 09:49:45 -0500, "Dave M" <dgminala@mediacombb.net> >wrote: > >>Has anyone used any of the consumer-grade audio power amps such as the >>LM1825, TDA2030, or TDS7297 as a basic DC power opamp? >>Any reason they shouldn't be used as power supply regulators, TEC >>controllers, etc? >> >>Dave M >> > >A number of those audio power amplifiers aren't designed for direct >coupling, so some fudge will be necessary to get them working... so >that, in conjunction with an OpAmp, they can oscillate >:-}
You do not even need an opamp, I had an old tube amp driving a car ignition coil as my first HV generator, and simple feedback to the phone input. Being able to oscillate is a plus, we are, in some way also oscillators. No ocillations = death.
On Mon, 15 May 2017 16:07:37 GMT, Jan Panteltje
<pNa0nStpealmtje@yahoo.com> wrote:

>On a sunny day (Mon, 15 May 2017 09:03:06 -0700) it happened Jim Thompson ><To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote in ><i6kjhc5hj95827e6d6q0pcjv0gj64h8cd4@4ax.com>: > >>On Mon, 15 May 2017 09:49:45 -0500, "Dave M" <dgminala@mediacombb.net> >>wrote: >> >>>Has anyone used any of the consumer-grade audio power amps such as the >>>LM1825, TDA2030, or TDS7297 as a basic DC power opamp? >>>Any reason they shouldn't be used as power supply regulators, TEC >>>controllers, etc? >>> >>>Dave M >>> >> >>A number of those audio power amplifiers aren't designed for direct >>coupling, so some fudge will be necessary to get them working... so >>that, in conjunction with an OpAmp, they can oscillate >:-} > >You do not even need an opamp, >I had an old tube amp driving a car ignition coil as my first HV generator, >and simple feedback to the phone input. >Being able to oscillate is a plus, >we are, in some way also oscillators. >No ocillations = death.
I used an old classic coil, and discharged an oil cap into it with a thyratron tube. The spark climbed over the insulator back to the primary terminals, so I had to add an oil-filled extension tube. Messy. -- John Larkin Highland Technology, Inc lunatic fringe electronics
On a sunny day (Mon, 15 May 2017 09:17:13 -0700) it happened John Larkin
<jjlarkin@highlandtechnology.com> wrote in
<aukjhchaghn3mtoc0oub3gne03c7uf7n6a@4ax.com>:

>I used an old classic coil, and discharged an oil cap into it with a >thyratron tube. The spark climbed over the insulator back to the >primary terminals, so I had to add an oil-filled extension tube. > >Messy.
These days it is so easy: http://www.ebay.com/itm/141077605344 I have one, but do not think it really is 400 kV. More like 40 kV perhaps. Had no time / urge to play with it... Too many ESD sensitive parts around,,,, There are a lot of those Tesla coil projects around too: https://www.google.nl/search?q=tesla+high+voltage+coil&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwjVl5GtrPLTAhXFUlAKHYBjDc4QsAQIPQ&biw=1590&bih=700 Nice pictures!
On Mon, 15 May 2017 16:46:44 GMT, Jan Panteltje
<pNa0nStpealmtje@yahoo.com> wrote:

>On a sunny day (Mon, 15 May 2017 09:17:13 -0700) it happened John Larkin ><jjlarkin@highlandtechnology.com> wrote in ><aukjhchaghn3mtoc0oub3gne03c7uf7n6a@4ax.com>: > >>I used an old classic coil, and discharged an oil cap into it with a >>thyratron tube. The spark climbed over the insulator back to the >>primary terminals, so I had to add an oil-filled extension tube. >> >>Messy. > >These days it is so easy: > http://www.ebay.com/itm/141077605344 > >I have one, but do not think it really is 400 kV.
400K Chinese volts. You have to factor in the exchange rate. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com