UCD 25 watts to 1200 watts using 2 mosfets

[don2007ksa]

Hi to all of you guys,i'm new here what i have been observe from the post was there are some schematic's posted,feedback is injected at + of LM311 and THEY OTHER WAY AROUND - NEG.If we are talking OSCILLATION guy"s is this negative injected feedback can make oscillation frequency higher?regardless the RC feedback CIRCUIT,Andrewlebon posted schematics with ref. OSCILLATOR & protection circuit are there any advantage of using this circuit compared to the other schematics posted here,thank's.

 

[CPX]

Yes there are...faster switching...smaller inductor,less high frequency cuttoff but lower efficiency.

 

[don2007ksa]

thank's CPX, any suggestion from andrewlebon circuit?beacause I'm interested,the clocking version look's like pure CLASS D audio amplifier,please correct me if i'm wrong.

 

[don2007ksa]

HI ANDREWLEBON i'm interested on your design,planning to build one.Can you post some wave form from oscilloscope,does the ref. oscillator makes more clearer P.W.M. output.thank's a lot Anrewlebon,hope to hear more from you.

 

[CPX]

i think andrewlebon madea self oscillating class D amplifier not a fixed frequency one.

 

[andrewlebon]

bridging ucd amplifier

Hi
greetings is this simple bridge schematic ok to bridge ucd 1200 for 8 ohms load ic TLO71 zeners 6.8volts 1 watt
warm regards
andrew lebon

 

[chinokscapsighter]

Nice schematic andrewlebon tnx for sharing...

 

[CPX]

andrewlebon avoid tl071 .. i recomand a simetrical inverting non inverting amplifier with lm833

 

[norazmi]

CPX post example schema pls

 

[CPX]

Like this:

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[norazmi]

Thanks CPX

 

[CPX]

We're welcome.
You can even use ultra low noise opamps if you find you ucd noisy,decrease lm311 gain to 5x and increase its supply rails to +-15v and use this modified circuit to obtain total gain 25x with global noise much better than with standard lm311 with gain of 25.

An externally hosted image should be here but it was not working when we last tested it.

 

[norazmi]

ok, i`ve some issue when up the gain of the op-amp, it will distort the input signal if the gain is too much even at low volume, so i think need to find out the maximum gain can be accepted for each amp, 25x gain lol its too much i think, but i like ultra low noise.

regards.

 

[Dimonis]

We're welcome.
decrease lm311 gain to 5x and increase its supply rails to +-15v

What relationship between supply and gain?
Optimal gain is about 10.

 

[CPX]

Yes gain 10 is good..but snr is better with gain decrease if you use a ultra low noise op amp befere ...
If you decrease gain you have to increase lm311 supplies to avoid clipping..for gain 10 and +-12 volt suplies you can have maximum 60 volt rms output,for gain 5 you can have maximum 30 and so on...for gain 5 and +-6 volt you can have maximim 15..etc

 

[andrewlebon]

bridging ucd amplifier

Hi Cpx
greetings thanks for sharing schematics
warm regards
andrew lebon

 

[manojtm]

Hi All

Just posting My New Design PLS check any correction have ,noted

 

[Dimonis]

Yes gain 10 is good..but snr is better with gain decrease if you use a ultra low noise op amp befere ...
If you decrease gain you have to increase lm311 supplies to avoid clipping..for gain 10 and +-12 volt suplies you can have maximum 60 volt rms output,for gain 5 you can have maximum 30 and so on...for gain 5 and +-6 volt you can have maximim 15..etc

I see , clipping occures on the input , not at the output
I'm using the inverting kind of input , hence i'll dont get any clipping even at low supply.

 

[andrewlebon]

HELLO

Hi Manojtm
greetings whats power of amp at 80 volt dc supply and is it suitable for 2 ohms load nice work
warm regards
andrew lebon

 

[manojtm]

thanks
RMS 710W @ 4ohm