Cookies-law

Cookies help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
http://www.overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please leave this website now. Many thanks for your understanding.
Amazon Warehouse Deals ! Now even more Deep Discounts ! Check out these great prices on slightly used or just opened once only items.I always buy my gadgets via these great Warehouse deals ! Highly recommended ! Many thanks for supporting OverUnity.com this way.

User Menu

FireMatch

FireMatch

CCKnife

CCKnife

Poplamp

poplamp

CCTool

CCTool

LEDTVforSale

Magpi Magazine

Magpi Magazine Free Rasberry Pi Magazine

Battery Recondition

Battery Recondition

OverUnity Book

overunity principles book

Arduino

Ultracaps

YT Subscribe

movieclipsfree

movie clips free

Gravity Machines

Tesla-Ebook

Magnet Secrets

Lindemann Video

Navigation

Products

Statistics


  • *Total Posts: 482318
  • *Total Topics: 14218
  • *Online Today: 44
  • *Most Online: 103
(December 19, 2006, 11:27:19 PM)
  • *Users: 3
  • *Guests: 161
  • *Total: 164

Facebook

Author Topic: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?  (Read 7681 times)

Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Hi Folks,
  I'm calling on the electronics wizards of the forum, to ask if anyone can suggest a simple amplifier circuit that meets the following criteria.

 - Input Power: 15v DC, up to 40 Amps
 - Input Signal: 10v Pk - from a sig-gen
 - Output: Same as input (but AC :))
 - Fully inverting
 - Frequency from 30 KHz to 30MHz (is this range too big?)

I would intend to use this amplifier for the following projects:
 - Stan Meyer type HHO Generation
 - Vialle Generator Rep
 - Any (many) other RF amplification purposes...

Your input is received with thanks. :)

Regards, Tim

Free Energy | searching for free energy and discussing free energy


Offline poynt99

  • TPU-Elite
  • Hero Member
  • *******
  • Posts: 3560
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #1 on: January 30, 2014, 09:30:42 PM »
 ;D


Offline TinselKoala

  • Hero Member
  • *****
  • Posts: 13093
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #2 on: January 30, 2014, 09:52:05 PM »
Raid the ham shack!

Collins 30L-1 !
Drake L-4B !
Ameritron AL-572 !




Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #3 on: January 30, 2014, 10:18:44 PM »
Raid the ham shack!
Collins 30L-1 !
Drake L-4B !
Ameritron AL-572 !

TK, mate, those amps are all a) out of production, and b) over £1000...  :o

I was hoping for something less than £100...

Is there any current HAM gear that you'd rate - that would be able to use the output from a sig-gen? I know most of them need many watts of input power...

I was expecting more mosfets etc...?

:)
Tim

PS: Poynt99 ?


Offline gyulasun

  • without_ads
  • Hero Member
  • *****
  • Posts: 3379
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #4 on: January 31, 2014, 12:12:25 AM »
Hi Tim,

Your specifications for a 'simple amplifier circuit' are not readily met: the main problem seems to insure the lower frequency response of 30 kHz. Normally the wideband transistor power amplifiers that are mainly available at relatively moderate price start from 1.5 MHz or so, this 'limitation' is mainly due to
-the nature of the transmission line transformers used for impedance matching
-the need for such wide frequency negative feedback for the active devices used (phase shift in the feedback loop)

See this paper, it nicely discusses these, you get a good glimpse on what are involved when designing such amplifiers:
http://www.nxp.com/documents/application_note/NCO8703.pdf

Also a good paper:
http://www.eetasia.com/ARTICLES/2001APR/2001APR03_RFD_AN3.PDF?SOURCES=DOWNLOAD

Just designing the wideband transmission line transformers, these are very good papers in two parts:
http://www.radio-kits.co.uk/radio-related/Linear_PA/ECO6907.pdf
http://www.radio-kits.co.uk/radio-related/Linear_PA/ECO7213.pdf

One more thing: the 15V DC supply input voltage is a bit low, when you expect 30-40 Amper output current, you would have to trade for 24V or higher supply voltage. If 13V or 15V is a must, you would have to combine several lower power amplifiers (also with power combining wideband transformers) to arrive at the needed output.

Lastly: such amplifiers are designed for driving 50 Ohm loads and you need to protect the active power devices when the load changes in a wide range like during HHO generation or the many other tasks you expect to perform.

See some component prices, out of the many (best prices maybe on ebay?) http://www.communication-concepts.com/index.php/components/rf.html

rgds, Gyula

Free Energy | searching for free energy and discussing free energy

Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #4 on: January 31, 2014, 12:12:25 AM »
Sponsored links:




Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #5 on: January 31, 2014, 11:36:00 AM »
Hi Gyula,
  thanks for your reply, and the links, I'll check them out in a bit...

I did anticipate the range might be a problem, and I thought it might need a different set of mosfets for each application...

I suppose what I'm asking is: There are thousands of amp design out there - is there a particular circuit configuration / architecture which anyone would recommend from experience?

 - Few components, easy to build
 - Inverting output...
 - Driven by a signal generator
 - Run from DC supply

Commercial RF amps are expensive, and seem to need a large input signal too (i.e. from a pre-amp...?)...

Regards, Tim

Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #6 on: January 31, 2014, 09:20:53 PM »
I built this today - it's a single MOSFET amp - from this page, for running my Vialle generator replication...:
http://jnaudin.free.fr/rvproject/html/ugentest27.htm

It's not an inverting amp... But it's pretty :)

So, guys, suggestions, links, recommendations, experiences - for a simple inverting one?

Free Energy | searching for free energy and discussing free energy

Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #6 on: January 31, 2014, 09:20:53 PM »
Sponsored links:




Offline mscoffman

  • Hero Member
  • *****
  • Posts: 1379
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #7 on: January 31, 2014, 10:07:35 PM »
Tim,


Usually in amplifier theory one simply swaps the load
from the source to the drain or emitter to collector.
The load is a resistor so it has two ends and attachment
to either ground or Vcc is possible. In the real world
the load maybe has one "end" and the other must be grounded.
Once the load has been swapped the designer may
have to "clean up"  the device gate or base drive and bias
so that it "steps over" the load.


In an AC amplifier a capacitor or transformer can
be used to couple of one stage to another
or the load. If one must have DC coupling then
there is usually a PNP or PMOS complement
device that can be used to help simplify the (non) inverting amplifier.
The complimentory device has similar specs but often
times the positive versions are slightly less efficient
then the negative version which are then used more
often.


:S:MarkSCoffman

Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #8 on: January 31, 2014, 11:07:10 PM »
I'm sorry Mark, but I don't understand a word of what you just wrote... Load swapping? 'Stepping over'? Coupling Stages? Say what?

I was hoping for simple circuits people have built and found to be good, or links to similar... Something practical to build... The theory is endless - it seems - and I just looking for something practical to start off with... I need to build things to understand the theory...

Offline Qwert

  • Hero Member
  • *****
  • Posts: 937
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #9 on: February 01, 2014, 12:55:09 AM »
http://www.tuks.nl/pdf/Reference_Material/Magnetic_Amplifiers/Platt%20-%20Magnetic%20Amplifiers%20Theory%20and%20Application%20-%201958.pdf

http://teslapress.com/magamp.pdf
This link is to a short document "Magnetic Amplifiers". On pages 4 and 5 (6 and 7 / 24 of the pdf) you find this (the first page):
"With the addition of two rectifiers (5), the device generates and controls a d.c. load from an a.c. supply."...
and on another page:
"Figures 6 and 7 show further developments with the addition of feedback. Gains of up to several million per stage have been obtained with these circuits."
« Last Edit: February 01, 2014, 10:40:15 AM by Qwert »

Free Energy | searching for free energy and discussing free energy

Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #9 on: February 01, 2014, 12:55:09 AM »
Sponsored links:




Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #10 on: February 01, 2014, 11:18:21 AM »
See this paper, it nicely discusses these, you get a good glimpse on what are involved when designing such amplifiers:
http://www.nxp.com/documents/application_note/NCO8703.pdf

Hi Gyula,
 I've had a chance to look at the links you posted properly, and i realise that your first link did answer my question about as well as anything could. Thanks. :)

The design with the two BLF177s is exactly the sort of thing i was looking for, and the build cost would be under £100 too. Plus there's loads of good info in there explaining the theory. It looked too technical yesterday - i was in a building mood - but today it makes sense...

I will study this, and the other papers, and see if I can learn it...

Thanks again.
Regards, Tim
 

Offline tim123

  • Hero Member
  • *****
  • Posts: 509
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #11 on: February 01, 2014, 02:57:59 PM »
http://www.tuks.nl/pdf/Reference_Material/Magnetic_Amplifiers/Platt%20-%20Magnetic%20Amplifiers%20Theory%20and%20Application%20-%201958.pdf

Hi Qwert,
 those are cool devices - but i think they can only amplify an AC supply... Would be good for modulating an existing signal, but not for generating one...(?)

Regards, Tim


Offline Qwert

  • Hero Member
  • *****
  • Posts: 937
Re: Simple, Cheap, Broadband, Linear, Power Amplifier Circuit Designs...?
« Reply #12 on: February 01, 2014, 11:01:10 PM »
Hi Qwert,
 those are cool devices - but i think they can only amplify an AC supply... Would be good for modulating an existing signal, but not for generating one...(?)

Regards, Tim

My feelings were also this kind at first. But as I keep it reading deeper and deeper, I see something different. But only experimenting can prove or disprove this for sure.

 

Share this topic to your favourite Social and Bookmark site

Please SHARE this topic at: