Strobe the decoder with your own hands

[Экко]

And the output of the LM567 works in key mode

you are not right. the output voltage changes smoothly from 1 to 5V. depending on the amplitude of the input. When I served on the input signal amplitude e.g. 40% of max. LEDs glow dimly. Maybe because I have NE567N
on your diagram the letters poorly sealed. If you have collected, please write a list of items and parameters. What do you have with the response to other frequencies? My scheme there are 2 drawbacks: the response to other frequencies ( though weak) and is not uniform burning of the diode when it is low amplitude. If you plan no mistakes, then of course great. Gather and separate your circuit sometime

[Ломан]

the output voltage changes smoothly from 1 to 5V. depending on the amplitude of the input. When I served on the input signal amplitude e.g. 40% of max. LEDs glow dimly. Maybe because I have NE567N

I haven't worked with NE567N, but I think that is the same as the LM567. According to the description from the manufacturer have it works in a key mode. I was convinced in practice myself. What You have measured the output voltage? If the voltmeter, then everything is clear. At low amplitude of the input signal, the output starts to switch with great frequency from 5V to 0V. The voltmeter on this frequency do not have time to react and shows some average value (as well as what the eye sees the average brightness value of svetodiod). If the plug to the output of the oscilloscope, it will be immediately evident.

on your diagram the letters poorly sealed. If you have collected, please write a list of items and parameters.

Strange, when I open the picture and then click on it again, the scale is increasing and we can see clearly. If necessary, you can of course make a list of items.

what do you have with the response to other frequencies?

The scheme works pretty well on other frequencies react poorly. But like any other filter, completely remove the influence of other frequencies is impossible. It all depends on the difference between the interfering and useful frequency and amplitude of the disturbing frequency.

In my circuit other values of capacitor and resistor on the 6th leg of the chip (0.047 UF and 1.1 kOhm, respectively). With these values the circuit operates more stably and the effect of other frequencies less.

[Экко]

Strange, when I open the picture and then click on it again, the scale is increasing and we can see clearly.

all realized
but the schema you somewhere or found yourself painted?
Yes, the signet would be nice.
And I see there are two amps per channel.. and not easier to just make a transistor switch?
to measure the voltage on the 1 the conclusion: Yes, it is changing, but how: when no signal input - is 3.8 V, when the signal is on full - is 3 V. it is Strange somehow.

(as well as what the eye sees the average brightness value of svetodiod).

reminds of the PWM modulation. Maybe it's not so bad? To adjust the brightness of the LEDs put those PWM modulators that by changing the duty cycle adjust the brightness.

[Ломан]

and the scheme you somewhere or found yourself painted?
Yes, the signet would be nice.

Scheme my. The printed circuit Board of the ladies in the near future.

And I see there are two amps per channel.. and not easier to just make a transistor switch?
to measure the voltage on the 1 the conclusion: Yes, it is changing, but how: when no signal input - is 3.8 V, when the signal is on full - is 3 V. it is Strange somehow.

All right. The way it is changing. This auxiliary voltage inside the chip, which is not intended for external use. It is derived on the leg of the chip only in order to connect an external condensator. It is clear that this tension is not necessary in order to control the LEDs. This is the stage of the operational amplifier U2. It converts the mains voltage, varying from 3.8 V to 3V In voltage from 0V at the zero amplitude of the input signal to 0.8 V At the maximum amplitude.

Transistor switch to supply course can only he will work as a key, either to open and turn on the led, or to close and off.

The second stage on the U4 and the Q1 is transitory Converter "voltage-current". This means that the LEDs are powered by current that is proportional to the amplitude of the input signal frequency 19200 Hz. Washing current instead of voltage is more preferable as it provides a precise replica of the input form the form of light pulses. How important is this issue to the experts. I just tried to make a diagram which most accurately decodes the strobe signal.
Perhaps these two cascades would be possible with the help of circuit tricks to gather on one operational amplifier, but I don't see how to do it. And the price of operational amplifiers is now so small that much sense in this, I think, no.

(as well as what the eye sees the average brightness value of svetodiod).

reminds of the PWM modulation. Maybe it's not so bad? To adjust the brightness of the LEDs put those PWM modulators that by changing the duty cycle adjust the brightness.

Yes, this is reminiscent of the PWM modulation. Only when the PWM modulation duty cycle proportional to the amplitude of the modulating signal in all range of change of this signal. In our case, the switching of the 8th output of the LM567 from one state to another occurs only when the amplitude of the input signal is close to a certain boundary level. Accurately predict what happens in the moments of these switches, it is impossible. You yourself wrote that in Your circuit the led is unstable at low signal amplitude.<

[Guest]

Good afternoon.

Excellent development waiting for PCB's.

One comment or question. It seems to me that when writing Audi's sessions, the authors do NOT use the analog approach to the management of the LEDs in the glasses, and use a discrete signal is either there or not, ie if there is audiostrobe, the led will light up and do not use amplitude modulation of audiostrobe.

But it is desirable that said the authors, in particular a question to the esteemed Andrei Patrushev, what he lays in your session? Which mode of led control? Whether modulation of the amplitude of the gate signal?

If so, please add to the circuit switch mode with analog control, discrete, I think it's easy.

All of the above, IMHO, could be mistaken.

NP.

[Guest]

Oh, and I forgot, if you add a discrete mode, then PWM can be used to control the brightness of the LEDs, for the selection of a comfortable level, even in the brand MM is not everywhere sensibly implemented.

NP.

[Экко]

If so, please add to the circuit switch mode with analog control, discrete, I think it's easy.

what's the point? if be passed smoothly brightness, it will normally be transmitted rectangular pulses

But it is desirable that said the authors, in particular a question to the esteemed Andrei Patrushev, what he lays in your session?

well, according to my research its sessions, Yes, the scope mulsow changes with the aim of adjusting the brightness.

One comment or question. It seems to me that when writing Audi's sessions, the authors do NOT use the analog approach to the management of the LEDs in the glasses, and use a discrete signal is either there or not, ie if there is audiostrobe, the led will light up and do not use amplitude modulation of audiostrobe.

well, the authors define the shape of pulses when writing to the disks, and in the sessions of the importance of the settings of the program or MM. But it is about the pulse shape, the percentage scale can be set in the session.

[Экко]

Transistor switch to supply course can only he will work as a key, either to open and turn on the led, or to close and off.

but in your circuit the output still stands that the transistor switch.
if not difficult, describe how invertase: at the entrance of the 3.8 - 3, output 0 - 0.8 V

[Ломан]

but on your circuit at the output of the same is this with a transistor switch.

It is simply a matter of terminology. In General, under a transistor key understand a transistor that is switched so that can only be in one of two States: closed when the current through it does not pass, and open when it passes maximum current. The intermediate state is not used. In my scheme it is not. Transistor there works in tandem with the operational amplifier U4. Together they form the Converter "voltage-current". It uses all intermediate values of current - from 0 to maximum.

if not difficult, describe how invertase: at the entrance of the 3.8 - 3, output 0 - 0.8 V

It standardly circuit of the operational amplifier in the inverting mode of the adder. Op. the amplifier has two inputs - inverting, denoted in the diagram, the sign " - " and the noninverting ("+"). The signal output from LM567 1 is supplied to the inverting input of the adder (the input of the adder is left at the scheme output R3). Ie the output signal of the adder (U2A pin 1) will increase with decreasing signal at the output of the LM567.
The non-inverting input of the adder (U2A pin 3) is energized by DC voltage from the divider R2 - R1. This voltage is equal to 3.8 V. When the voltage at both inputs of the adder are equal, the output will be 0.

This link is a drawing of the PCB with layout and concept.
http://rapidshare.com/files/410870796/Audiostrob.rar
After some time I will give a picture of the finished device and commissioning instructions.

[Экко]

and here's a question for you, maybe someone wants to connect to the device from an external power supply, not from USB. I once tried to connect one self-made device to a computer, only to connect only one wire - the ground of this device (minus the PSU) on the ground of the computer, the computer hung and intermittently squeaked speaker. I can not understand what it was and is this when connected to the same decoder, because it is also common ground between the PSU, audio input.

[Ломан]

The scheme works like from USB or from external power supply. I tested it both ways. What happened in Your case, I don't know. And what was the power supply? And where have You connected the ground?

[Экко]

the Soviet power supply to 12V. his minus is connected to the ground of the computer (it is common to all known).

[Ломан]

And what kind of PSU? Pulse or a transformer?

[Экко]

a transformer

[Ломан]

It's hard to say what it was. I think some defect in the power supply. Computer case, if it is not connected to a 220V three-wire cable with a third wire grounding conductor, has a potential approximately equal to 110V. If the minus of Your power supply had the galvanic communication with a network of 220V because of malfunction or structural, in these moments of connection can have a little spark that created an electromagnetic pulse caused the computer to hang. Another explanation I have. In any case, what happened, happens quite rarely, and we shouldn't fear this.

[Guest]

..........
After some time I will give a picture of the finished device and commissioning instructions.

We are waiting to

On the question of powering of the decoder: if it is powered from 4 AA AA batteryli to remain functional?

NP.

[Экко]

4 penlight AA batteries to remain functional?

4 batteries = 6V. LM567 is powered by a wide voltage range, refer to Datasheet. The rest mikruhi - I don't know. But the best put to the input of the stabilizer of 5V and all will be good.

[Guest]

I have audibleair Autonomous, want to be tied to offline was. The scheme itself consumes little, the LEDs 20 MA at the peak (points a homemade one led), I think Batrak should last for several months.

NP.

[Экко]

I have audibleair Autonomous, want to be tied to offline was. The scheme itself consumes little, the LEDs 20 MA at the peak (points a homemade one led), I think Batrak should last for several months.

NP.

In any case, over to put the stabilizer if you have 4 batteries

[Ломан]

Thanks the file on the previous link. Added photos of the device and manual adjustment.

[Ломан]

About a supply from 4 batteries. The supply voltage can be changed within the range in which the work of the chip. LM567 for supply voltage 9V, but it OPA2344 only 7.5 V. If you are using another operational amplifier this voltage can be more. But the problem is that the decoder is adjusted for a specific voltage of the power supply (see hands. on the adjustment). Ie, if set for 6V, you always need to apply 6V. And due to the discharge of the batteries the voltage will fall. How this will affect the operation of the device, I now can not say.

In principle, in the schema you can use the internal voltage regulator. Only for ordinary linear regulator, like 7805, 6V at the input is small, minimum need of 7.5 V. and a stabilizer consumes a significant current for its own needs, when the battery power is not good. The problem can be solved using switching regulator. But the scheme of connecting these stabilizers harder.

[Ломан]

In the diagram, and the PCB was a mistake. My apologies. Now thanks corrected version.

[Экко]

To separatelybut anything to the audio is not Gud, in this case, some of the observed distortion in the headphones in time with the flashes points. I propose to add the schema headphone amp for TDA7050T. It's almost not complicate the scheme, because the amplifier consists of only 1 IC and two capacitors + volume control if needed.

Scheme pilka: http://www.nashgorod.ru/imgfiles/usr_fo ... 01c26c.jpg

[Ломан]

I agree. Headphone amp will not hurt

[Экко]

Think it is not necessary to fence the circuit with a LM567 but still with 2 operationname, it is easier to do 1 bandpass filter at 19200Гц, it is necessary to make active on operatsionnyi, then he will still reinforce that we need.