If so, then being a unbalanced audio device, relying on signal interconnects,
do you see that as sufficient ?
Totally agree Unbalanced is great, Unplugging or plugging interconnects when powered without a 0v , can be tragic.
Thanks. I take it you were not able to measure your sample, but that's ok, I will accept the data sheet. Now, what does it tell you? What is the range of the output impedance of the 7895 in the audio band? Does it ever reach anywhere near 4K79?
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No, but does not change its implementation of output and ground which are directly in parallel with LDR anode and cathode along with capacitance and potentiometer resistance.
Politely suggest you stop defending a 7805, and instead concentrate on seeing the better way of powering LDR's using a dedicated current source for anode and current sink
for cathode, with nothing as a parallel between them.
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Can we have that in English, please? I have no idea what you mean by all that, but your claims about the output impedance of a 78xx voltage regulator are just plain wrong. And, as DF96 has pointed out repeatedly, Light Dependent Resistors are not polar and do not have anodes or cathodes, though LEDs do.
Funnily enough Chris, I agree with you. The light output of an LED varies as a function of current, and if you want precise control of LED output, and hence LDR resistance, then a variable current source is the best way to do it. An LEDs Vf varies with current (and temperature) so varying voltage to the LED in series with a fixed resistance, will not change the current through the device in a linear way. Nothing to do with "sound quality", but a current source is the best way to control current through an LED. An LM317 is easily configured as a variable current source.
Having said that, most of what you write here is gibberish and you clearly have no understanding of the subject you write about, including your ridiculous "measurement" of a voltage regulator's output impedance.
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The figures within the graph for output impedance are from Texas Instruments data sheet,would you like to correct them if you think they are plain wrong ? Figure 7 page 10 http://www.ti.com/lit/ds/symlink/lm340.pdf
their address for contact is Dallas Texas 0800 446 934
And a Light Dependent Resistor indeed has an anode and cathode for its LED
as shown here: http://lunainc.com/wp-content/uploads/2016/06/NSL-32SR3.pdf shown on the Right hand side image as Anode lead and Cathode Lead
Have you tried a current source implementation ? was it better than the
parallel arrangement shown at Post 127 across the anode and cathode being 78xx + capacitance + pot resistance.
Where the anode and cathode have no parallel components at all is what you need to try, so current source and current sink, with no parallel capacitance or resistance - (internal to devices) or external via pots.
I would rate a LM317 arranged as a Vref/r regulator for anode of the device on its own, poor to average, with resulting audio, compared to with what can actually be achieved. But compared to Post 127's schematic - quite a leap forward.
then with a dedicated current sink for the cathodes better again
Your assertion of including ridiculous measurements argument would
need to be taken up with Texas Instruments. As shown by the measurements they did on a 78xx
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I would have thought such a measurement would tell me nothing of any use at all. It certainly will not tell me the output resistance of the regulator. Have you ever understood how a regulator works?Chris Daly said:
I think you will find that R20 is part of the feedback arrangements. Its exact value does not matter.
No. It is a regulated voltage source for the LED driver arrangements.
There is nothing harmful to escape from. The LED just sees a voltage source and a variable resistor.
No. On the contrary, unless you arrange for the two sources to exactly track each other (hint: this is impossible, except perhaps in Spiceworld) one will dominate and the other will hit a limit and cease to be a CCS. Poor engineering.
The 100k pot means that they are not "directly in parallel".
I don't understand your fixation about nothing in parallel with the LED.Chris Daly said:
There is absolutely no need for both current source and current sink. You simply need one, if you want current drive for the LED. The LED emits light based largely on the current; it does not know and does not care what voltage it sits at with respect to its own PSU ground or the audio signal ground. Do you understand what 'voltage' is?
In post 102 I asked about separate grounds. In post 104 you said the grounds were separated. Now which is it?
Take another look at the regulator schematic. You can clearly measure the resistance from output to ground and that is why I posted it. I measured a number of different brands out of circuit and they all measure 15K. This isn't going to make any difference after all because per your post #104 you stated the grounds were separated.
Do you even have a clue as to what your talking about?
An opto-isolator is an electronic component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. Commercially available opto-isolators withstand input-to-output voltages up to 10 kV and voltage transients with speeds up to 25 kV/μs. A common type of opto-isolator consists of an LED and a phototransistor in the same opaque package
The above is an explanation of the opto-isolator.
Note the "two isolated circuits" in the first sentence.
The above is an explanation of the opto-isolator.
Note the "two isolated circuits" in the first sentence.
Chris..... I'll help you out.
Voltage, electric potential difference, electric pressure or electric tension (formally denoted ∆V or ∆U, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's laws) is the difference in electric potential energy between two points per unit electric charge.
volt·age.
.
[ˈvōltij]
NOUN
physics
.
an electromotive force or potential difference expressed in volts.
"the ratio of two voltages" ·
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