Hello guys,
I am sticking on an issue:
I have a micro A.c. from 0.5 v to 5v in input and I want ALWAYS an output of 1.5v, whatever the input is.
The input is an audio signal coded with 80 bits per second called SMPTE Timecode.
I am doing a timecode decoder with arduino uno/leonardo, but my skills are quite near zero in this matter of power treatment.
My question: do you know a component or circuit who is do this treatment ?
Thanks for helping a French nerb.
I think you want a [u]Comparator[/u] which could "tell you" if there is a signal above or below +0.5V.
But there are "timing issues" that you'd have to figure-out because an AC waveform is below 0.5V (or negative) for part of every cycle).
To get 1.5V as a low current "signal" you can simply use a voltage divider (2 resistors). But if there is a low impedance load you might need a more elaborate circuit to step-down the voltage.
Then do you need to decode the time code, or just detect it's presence?
Hi,
Google
smpte time code reader arduino
Tom.. 
Hello guys,
Thanks for answers:
- I know how to decode a timecode.
- my question is only about controlling power input because devices bringing timecode are different, regarding the signal
-@dvddoug, I don't think it's correct. For example if I have a signal of +/- 0.9v I need an output of 1.5v. If I have a signal of 2.3v I need an output of 1.5v, etc.
Does a comparator do that ?
SMPTE timecode is 80-bits per frame (2000-2400 bps) at play speed.
There are several implementations of an Arduino LTC reader on the forum and elsewhere.
The greatest challenges are input signal conditioning without clipping & mangling the waveform, and the ability to read the timecode at high speed...
e.g. spooling at 20x speed returns the bitstream at 40-50kHz... forward or reverse.
Thanks Lastchancename.
I do agree. Implementation on forum does talk about this particular point on how to manage different income source/voltage dealing with timecode.
Or perhaps do you have a link?
I didn't found nothing on every links I red.
Did you see this one?
https://forum.arduino.cc/index.php?topic=618909.0
Yep. That's the code I work with. As he said in post #10, if the signal gain is not good it's not working. That's why I want to do a circuit to maintain an input gain to 1.5v.
Any idea ?
Try these...
Attached pics
First is very simple, second has separate analog and shaping stages...
and AC coupled, so you can lose the bridge)
(output is on the far right side)
Waouh! Where did you get those schemas ? Do you have value for the first one? Any link ?
Thank you !
Just a google search on images for SMPTE input circuit.
The second is probably perfect for you.
Thanks !!! I Will study them.