"Jerry Norris" schreef in bericht news: snipped-for-privacy@news.tpg.com.au...
Your simulater does not seem to function the same way in both cases. I suppose it has to do with the "ground" of your signal source that seems to have no relation to the rest of the circuit having the voltage sources floating. Guess the simulater chooses a common ground itself.
petrus bitbyter
See...
Newsgroups: alt.binaries.schematics.electronic Subject: Re: Convert emitter follower to PNP - Follower_Norris.pdf Date: Fri, 17 Jun 2011 17:59:49 -0700 Message-ID: ...Jim Thompson
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| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
It seems to me there is a -6V potential between the -3 and -9V batteries. That is the power I want to use, not something referenced to an arbitrary ground, as in the inout signal.
Jerry Norris
Sorry, but downloded all the messages on the above group and could not find a reference to this.
Please advise how to view it.
Many thanks,
Jerry Norris
Yes, Jim that is the intent of the project. Please allow me to explain.
I have a 20Hz sinewave from a function generator. It obviously has its own ground reference, ie. 0-2.5Vpp.
I would like to convert this to two identical signals. One swinging 5V (or so) between the +3 and +9 battery potential. The other likewise swinging 5V, but between -3 and -9 batteries.
IOW the two output signals are to appear soley between the two dissimilar plus battery terminals, and two dissimilar minus battery terminals respectively ... and not with any reference to an "offset" or common ground.
I assume, to see it, the CRO probe would be placed across the 1K load resistor shown in my diagram.
I realize this is not conventional practice, but the nature of my project is a physics experiment.
Any way the above can be achieved, discrete or op amp, would be fine.
Jerry Norris
OK, but first define the problem better.
John
Well, then just connect a single power supply between the input and the output. Done.
John
Double click on the message ID. If you can't get it, I'll put it up on my website. Let me know. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
I use Free Agent newsreader. It doesn't appear to support this function. I will check the binary group tomorrow. Maybe my server is slow.
Sorry for the trouble.
Jerry
I would then need to build two dedicated signal generators, one that runs off +3 and +9, and the other from -3 and -9.
For example two XR2206's, which will run on split supply.
However, the output signals of the two emitter followers (npn and pnp versions), shown in my posted circuits, need to be identical, except for the differing potential.
Maybe you have something in mind, but I don't see how this can be easily achieved without using one input signal for both.
Jerry Norris
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
The better way, use OpAmps...
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Thanks for the schematics. I will breadboard them today.
Can they be separated into two circuits, one running off +9V and the other -9V, so I can have the option of applying an inverted signal to one?
I can see the positively and negatively shifted waveforms on your sims, but where is the return for each?
As previously indicated, I did not want ot reference back to the input signal ground. IOW the output returns, thorugh the load resistances, should be eually offset from the signal ground.
For example, if the swing is 2.5 to 7.5V, the load return needs to be at 2.5V, not signal ground. Same for the other signal, but with minus signs added. Perhaps I am not reading the diagram correctly.
BTW did you ever know Harry Lang on E Briown St? He introduced me to electronics when I lived in Phoenix years ago.
Jerry Norris
Yes. (Observe that the upper OpAmp is running on +9V/0V, and the lower OpAmp on 0V/-9V)
Measured relative to ground.
SOMEWHERE there HAS to be a potential between the two GROUNDS/RETURNS.
+9V means 9V relative to GROUND, -9V means -9V relative to ground.I don't know the name, and I've lived here just shy of 50 years. ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
Late at night, by candle light, snipped-for-privacy@lightharbor.com (Jerry Norris) penned this immortal opus:
You need just one generator, outputting 6vpp (+/- 3Vp). Split the signal, in one branch connect a 6V DC source between the signal and the output with + going to the output. For the other output just invert the source.
+| 6V +--| |--------o -3 to -9 V | | +-----+ | | 6V|+ _ +--| |--------o +3 to +9 V / \ | | ~ |-3 to + 3 V \_/ | ---- YD.
-- Remove HAT if replying by mail.
How about something like either of these circuits then?
Jerry Norris
I can see that you and Jim are going to be best of friends.
John
Looks like you are over your head when trying to understand electronics.
What kind of isolation do you need between input and the outputs?
Is the signal always 20Hz?
Source impedance? ...Jim Thompson
--
| James E.Thompson, CTO | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
I gotta say, this has been one of the longest threads based on the simple practice of a single transistor phase splitter circuit for which you feed the emitter side a (-) source instead of the common to generate your +&- outputs. One only needs to tailor the DC bias on the base to get the desired DC offset!
Hell, you can even use a single supply source using a V-ground... 20 v source into a Vground network ... :)
Jamie
Not knowing everything that is needed for a proper design is a big issue how ever, if you were to look at this problem from a basic electrical point of view...!!!
One common configurable control transformer found in basic electrical panels that allow various voltage configs. These xformers have 2 windings on the output, (X1,X2 and X3,X4), which you use as separate outputs if you wish.. You config the input so that yields a 1:1 ratio in the transfer..
Each secondary can be fed with a DC offset. One with + voltage and the other, - voltage.
With that, the applied 20hz, which should pass fine on these transformers, will be seen with the desired offsets on the other side.
If the signal is 180 unmatched, you simple flip one of the secondary outputs. Also this gives isolation with the input signal..
Problem solved! Next? :)
Jamie
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