led multiplexing dim or ??

[MrDEB]

Audio out w/o noise?

I might have done this route before??
hopefully able to input audio into 10 filters (20 = stereo), do the matrix displays AND use the same filters for audio out to a 25w amp.
Adding diodes might do it?
I changed the circuit flow for left to right and peak detector cap.

 

[audioguru]

Audio does not pass through a diode.
The peak detector does not work when it is fed from the volume control. The detector's capacitor must charge quickly from the high output current of a new opamp that must be added to each filter.

The peak detector's capacitor must have a resistor across it to discharge it. 100k?

 

[MrDEB]

The oriential circuit is wrong?

refering back to the oriential circuit, It has the cap going to ground and the diode feeds it.
I can maybe see why the second op amp but the resistor??
As I am not to proficent in this audio stuff I have to take your knowledable input.
What should I look for in a TINA simulation?

 

[MrDEB]

Is this the layout you are thinking?

I put the circuit into TINA and not knowing what I am really looking at??

 

[audioguru]

A resistor is needed to discharge each peak detector capacitor.

The switching transistor discharges the capacitor into the 10k volume control at the input to the LM3914 in the Oriental circuit. The time constant is 10ms but the multiplexing does not allow the capacitor to discharge much so it remains charged and the displayed level of its frequency is wrong.

 

[audioguru]

Your first opamp reduces the level of the input signal instead of amplifying it.
Your 1m resistor has a value of only 0.001 ohms. It is supposed to be 1M which is 1 million ohms.
I don't think Tina was told what the circuit is supposed to do.

 

[MrDEB]

Didn't Tell TINA what to do

being a women she wouldn't listen anyways--lol
I never realized I needed a capital M. Was going by what happens when I use a capital K - error message.
On the first op amp?? I think I go it wired right??
will insert a resistor across the cap.
what woulds happen If I inserted the resistor across the transistor in such a way that the transistor drains the cap through a resistor??

 

[MrDEB]

I reversed the inputs of op amp

?? see no difference? must be doing something wrong.
I now have the resistor going across the cap when transistor is on???
weather this is kosher??

 

[audioguru]

The voltage loss of your first opamp is 0.2 times. If the resistors are swapped then the gain is 5 times.

The transistor following the peak detector capacitor is a switch and 10 transistors will be connected together. So the 100k resistor must be across the capacitor before the transistor.

 

[MrDEB]

made changes

changed the resistors on input. swaped the op amp inputs back (+ to ground)
moved resistor across the cap
wave forms look different but really don't know what I am looking for.
why does the gain on the input op amp (vf3) go from just below 0 gain before switching resistors to -200 and proceeding towards -100 after switching the resistoprs around. Isn't this going backwards?

 

[audioguru]

What is the input signal level?
Is the input signal DC, a single frequency or is it swept frequencies?
What are the power supply voltages?

The voltage gain of the first opamp is 100k/20k= 5.0. So an input of 1.0V results in an output of 5.0V. It has no input capacitor so it amplifies AC and DC.

-120dB is the reduction of a signal to one part in one million.
-180dB is one part in one billion.
-240dB is one part in one trillion.
Something is seriously wrong with your simulation.

The output transistor has its base grounded. It doesn't have a load so its output is nothing. The peak detector capacitor has a DC voltage that is the peak voltage of the filter circuit.

 

[MrDEB]

Base is supposed to be connected to 4017

for simulation purposes I put a switch to simulate the output of the 4017
the input is audio from various sources-TV, stereo, Ipod, radio
should I add a cap in series with the input?
power supply is 5v split supply (see batteries)
I will try the simulation w/ a capacitor on the input.

 

[audioguru]

The generator in the simulator should feed swept frequencies from about 100Hz to about 10kHz at about 200mV RMS into the input.
Then the first opamp will have a flat response and the filter will have a peaked response. The output is a DC level that is pulsed by the transistor.

If all 200 LEDs are lighted brightly then their total current will be about 2A to 4A and batteries are not suitable. If the LEDs are dim then many AA Ni-MH rechargeable cells will last for a while.

 

[MrDEB]

unit to have a powersupply

utilizing 7812 and 7912 (going to run the unit at 12 v not 5v (my bad for simulating w/ 5v battery)
the leds are going to be multiplexed so only 20 leds posiable o be lit at any one time.
will recheck the input generator properties.

 

[audioguru]

Of course! Multiplexing reduces the average current and the average brightness. Then many AA rechargeable cells will power it for more than 24 hours with pulsing sounds. The 12V regulators need a minimum input voltage of 15V. A lot of battery cells. The 24V total supply voltage might fry something.

 

[MrDEB]

batteries argnt even going to be used in the bigger 10 band eq unit. Only the pocket unit which will use a stereo TILT circuit and 2-lm3916's with 10 smd leds per display.
I need to redo my TINA simulation with proper ps voltages. What should I use for the audio input properties?. just been setting at 5v sinewave

 

[audioguru]

The big EQ unit doesn't have many LEDs so its power consumption is very low.

The little pocket unit has many LEDs so its power consumption is high.

I recommended an audio input in the simulator of "swept frequencies from about 100Hz to about 10kHz at about 200mV RMS".