Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > sci.electronics.design > #460350 > unrolled thread

Using consumer-grade power amp as Power opamp

Back to article view | Back to sci.electronics.design

Contents

  Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-15 09:49 -0500
    Re: Using consumer-grade power amp as Power opamp Don Y <blockedofcourse@foo.invalid> - 2017-05-15 08:09 -0700
      Re: Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-16 12:53 -0500
        Re: Using consumer-grade power amp as Power opamp tabbypurr@gmail.com - 2017-05-17 03:04 -0700
        Re: Using consumer-grade power amp as Power opamp mrdarrett@gmail.com - 2017-05-18 09:02 -0700
    Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-15 08:18 -0700
      Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-15 17:15 -0700
        Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-16 05:49 -0700
          Re: Using consumer-grade power amp as Power opamp "Dave M" <dgminala@mediacombb.net> - 2017-05-16 13:00 -0500
    Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 15:57 +0000
    Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-15 09:02 -0700
    Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-15 09:03 -0700
      Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 16:07 +0000
        Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-15 09:17 -0700
          Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-15 16:46 +0000
            Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-15 10:08 -0700
              Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-15 11:13 -0700
              Re: Using consumer-grade power amp as Power opamp Clifford Heath <clifford.heath@gmail.com> - 2017-05-16 10:14 +1000
                Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-16 08:36 +0000
    Re: Using consumer-grade power amp as Power opamp Tim Wescott <seemywebsite@myfooter.really> - 2017-05-15 12:48 -0500
      Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-15 11:18 -0700
        Re: Using consumer-grade power amp as Power opamp Tim Wescott <tim@seemywebsite.really> - 2017-05-16 10:08 -0500
          Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-16 11:19 -0700
            Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-16 11:32 -0700
              Re: Using consumer-grade power amp as Power opamp Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-05-16 16:02 -0400
                Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highlandtechnology.com> - 2017-05-16 20:19 -0700
    Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-15 16:59 -0700
      Re: Using consumer-grade power amp as Power opamp Chris Jones <lugnut808@spam.yahoo.com> - 2017-05-16 21:54 +1000
        Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-16 06:06 -0700
        Re: Using consumer-grade power amp as Power opamp tabbypurr@gmail.com - 2017-05-16 06:57 -0700
    Re: Using consumer-grade power amp as Power opamp Winfield Hill <hill@rowland.harvard.edu> - 2017-05-15 18:42 -0700
      Re: Using consumer-grade power amp as Power opamp krw@notreal.com - 2017-05-15 21:55 -0400
        Re: Using consumer-grade power amp as Power opamp Winfield Hill <hill@rowland.harvard.edu> - 2017-05-16 05:53 -0700
          Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-16 14:23 +0000
          Re: Using consumer-grade power amp as Power opamp krw@notreal.com - 2017-05-16 12:28 -0400
      Re: Using consumer-grade power amp as Power opamp "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> - 2017-05-16 20:27 +0100
        Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-16 16:03 -0700
          Re: Using consumer-grade power amp as Power opamp "Kevin Aylward" <kevinRemovAT@kevinaylward.co.uk> - 2017-05-17 19:34 +0100
            Re: Using consumer-grade power amp as Power opamp Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-05-17 11:47 -0700
            Re: Using consumer-grade power amp as Power opamp Phil Allison <pallison49@gmail.com> - 2017-05-18 04:43 -0700
          Re: Using consumer-grade power amp as Power opamp Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-05-18 16:30 +0000
        Re: Using consumer-grade power amp as Power opamp John Larkin <jjlarkin@highland_snip_technology.com> - 2017-05-16 16:07 -0700
    Re: Using consumer-grade power amp as Power opamp jurb6006@gmail.com - 2017-05-16 00:45 -0700
    Re: Using consumer-grade power amp as Power opamp sroberts6328@gmail.com - 2017-05-18 08:57 -0700
      Re: Using consumer-grade power amp as Power opamp George Herold <gherold@teachspin.com> - 2017-05-19 06:29 -0700

Page 1 of 3  [1] 2 3  Next page →

#460350 — Using consumer-grade power amp as Power opamp

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 

[toc] | [next] | [standalone]

#460352

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?

[toc] | [prev] | [next] | [standalone]

#460538

Don Y wrote:
> 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?


The reason for my interest in these parts is because I came across a 
half-full bag of them while helping a friend clean out his recently deceased 
dad's garage, and while I'm not really interested in building audio stuff 
anymore, I wondered if they could be useful in other applications.

Since their main purpose was to drive speakers, which are pretty reactive 
over the audio range, Zobel networks are commonly used with them.  So I'm 
sure they don't like to see a lot of reactance. Operating at DC, if they're 
not asked to handle a lot of AC power, then compensation might not be too 
difficult. That should be an interesting experiment.

I might give a shot at using one as a DC power supply regulator, or maybe to 
drive a power transformer or audio output transformer to make an AC voltage 
reference.  I've wanted one of those for a long time.  Hmmm... I wonder how 
they would like being run as BTL amps?

Thanks for all the suggestions and advice!!

Dave M 

[toc] | [prev] | [next] | [standalone]

#460653

On Tuesday, 16 May 2017 18:53:27 UTC+1, Dave M  wrote:

> I might give a shot at using one as a DC power supply regulator, or maybe to 
> drive a power transformer or audio output transformer to make an AC voltage 
> reference.  I've wanted one of those for a long time.  Hmmm... I wonder how 
> they would like being run as BTL amps?

I used to run TDA20nn as BTL without problem. Why wouldn't they?


NT

[toc] | [prev] | [next] | [standalone]

#460791

On Tuesday, May 16, 2017 at 10:53:27 AM UTC-7, Dave M wrote:
> Don Y wrote:
> > 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?
> 
> 
> The reason for my interest in these parts is because I came across a 
> half-full bag of them while helping a friend clean out his recently deceased 
> dad's garage, and while I'm not really interested in building audio stuff 
> anymore, I wondered if they could be useful in other applications.
> 
> Since their main purpose was to drive speakers, which are pretty reactive 
> over the audio range, Zobel networks are commonly used with them.  So I'm 
> sure they don't like to see a lot of reactance. Operating at DC, if they're 
> not asked to handle a lot of AC power, then compensation might not be too 
> difficult. That should be an interesting experiment.
> 
> I might give a shot at using one as a DC power supply regulator, or maybe to 
> drive a power transformer or audio output transformer to make an AC voltage 
> reference.  I've wanted one of those for a long time.  Hmmm... I wonder how 
> they would like being run as BTL amps?
> 
> Thanks for all the suggestions and advice!!
> 
> Dave M


Try selling them on eBay, then tinker with the ones that don't sell?

Michael

[toc] | [prev] | [next] | [standalone]

#460354

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. 

[toc] | [prev] | [next] | [standalone]

#460442

George Herold wrote:

-------------------------
> 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.
> 

  ** Dave's list is full of typos. 

It should read: LM1875, TDA2030 and TDA7294


....  Phil 

> I'm guessing the DC performance is not as good as it could be.  
> Lots of DC offset perhaps.  
> 
> George H.

[toc] | [prev] | [next] | [standalone]

#460491

On Monday, May 15, 2017 at 8:15:36 PM UTC-4, Phil Allison wrote:
> George Herold wrote:
> 
> -------------------------
> > 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.
> > 
> 
>   ** Dave's list is full of typos. 
> 
> It should read: LM1875, TDA2030 and TDA7294
> 
> 
> ....  Phil 
Thanks Phil,  The schematics for the LM1875 looks like the 
LM675.  Which is an oldie, but I still use it.  
(Again as you say it wants to run at a gain of 10 and above.)  

George H. 
> 
> > I'm guessing the DC performance is not as good as it could be.  
> > Lots of DC offset perhaps.  
> > 
> > George H.

[toc] | [prev] | [next] | [standalone]

#460540

George Herold wrote:
> On Monday, May 15, 2017 at 8:15:36 PM UTC-4, Phil Allison wrote:
>> George Herold wrote:
>>
>> -------------------------
>>> 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.
>>>
>>
>>   ** Dave's list is full of typos.
>>
>> It should read: LM1875, TDA2030 and TDA7294
>>
>>
>> ....  Phil
> Thanks Phil,  The schematics for the LM1875 looks like the
> LM675.  Which is an oldie, but I still use it.
> (Again as you say it wants to run at a gain of 10 and above.)
>
> George H.
>>
>>> I'm guessing the DC performance is not as good as it could be.
>>> Lots of DC offset perhaps.
>>>
>>> George H.


Yep, sorry for the typos... I had a visit to my opthalmologist that day and 
looking at anything that emitted light was like staring into the sun, so 
please forgive.

Right about the gain... that caution is mentioned on the first page of the 
LM1875.  DC offset coltage & current are only specified at 25C, and isn't 
great, for sure.


Dave M 

[toc] | [prev] | [next] | [standalone]

#460357

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.

[toc] | [prev] | [next] | [standalone]

#460358

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 

[toc] | [prev] | [next] | [standalone]

#460360

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

[toc] | [prev] | [next] | [standalone]

#460361

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.

[toc] | [prev] | [next] | [standalone]

#460363

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 

[toc] | [prev] | [next] | [standalone]

#460368

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!
 

[toc] | [prev] | [next] | [standalone]

#460374

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

[toc] | [prev] | [next] | [standalone]

#460388

On Mon, 15 May 2017 10:08:20 -0700, John Larkin
<jjlarkin@highland_snip_technology.com> wrote:

>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.

Sno-o-o-o-ort >:-}
		
                                        ...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

[toc] | [prev] | [next] | [standalone]

#460461

On 16/05/17 03:08, John Larkin wrote:
> 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.

Hah! It also says "1-2cm arc" which translates to 10-20kV in dry air.
That sounds possible.

[toc] | [prev] | [next] | [standalone]

#460482

On a sunny day (Tue, 16 May 2017 10:14:38 +1000) it happened Clifford Heath
<clifford.heath@gmail.com> wrote in <CgtSA.12714$YU2.8893@fx20.iad>:

>On 16/05/17 03:08, John Larkin wrote:
>> 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.
>
>Hah! It also says "1-2cm arc" which translates to 10-20kV in dry air.
>That sounds possible.

Indeed.

[toc] | [prev] | [next] | [standalone]

#460384

On Mon, 15 May 2017 09:49:45 -0500, 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

If the super-est best-est performance isn't an issue, a plain old op-amp 
driving an emitter follower stage often works well, particularly in a 1-
quadrant amplifier such as a regulator or TEC controller.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!

[toc] | [prev] | [next] | [standalone]

Page 1 of 3  [1] 2 3  Next page →

Back to top | Article view | sci.electronics.design

csiph-web