Analog VU meter for VCR

[Jeff Pelletier]

I've been trying to assemble an analog VU meter to hook up to a VCR.
I've got an analog panel VU meter, a bridge rectifier, and very little
knowledge of electronics.

I figured the easiest way to wire this, would be to splice the end of
an RCA cable. I've assumed that the shielded wire in the center is
positive. The bridge rectifier I have has four diodes (?) sticking
out, only one of which is labeled +. This one is slightly longer;
there's two the same length, and one very slightly shorter than the
rest. From what I've read the shortest should be the positive input
which would make the longer one marked + the output to the VU meter...

No matter what configuration I use, I dont get any readings
whatsoever. I could very well be wayyy off on my understanding of this
thing.

Jeff

 

[Mark Zenier]

In article <1d207761.0411261134.12c1189c@posting.google.com>,
Jeff Pelletier <jeff@basetwomedia.com> wrote:

I've been trying to assemble an analog VU meter to hook up to a VCR.
I've got an analog panel VU meter, a bridge rectifier, and very little
knowledge of electronics.

I figured the easiest way to wire this, would be to splice the end of
an RCA cable. I've assumed that the shielded wire in the center is
positive. The bridge rectifier I have has four diodes (?) sticking
out, only one of which is labeled +. This one is slightly longer;
there's two the same length, and one very slightly shorter than the
rest. From what I've read the shortest should be the positive input
which would make the longer one marked + the output to the VU meter...

No matter what configuration I use, I dont get any readings
whatsoever. I could very well be wayyy off on my understanding of this
thing.

1) A real VU meter has a built in rectifier. (A copper oxide low voltage
one, I think).

And 2) a silicon diode bridge needs at least 1.4 volts before it begins
to conduct. You probably just don't have enough signal for that.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Jeff Pelletier]

I was trying to plug it directly into a line-level output. From what
I've read, a "Hi-Fi" signal is 1.228 V DC (for 0 db) and consumer home
electronics are 0.316 V DC. Would this mean I'd require some sort of
amplifier?

I'm thinking of starting over with an LED VU Meter kit...

Thanks,
Jeff

1) A real VU meter has a built in rectifier. (A copper oxide low voltage
one, I think).

And 2) a silicon diode bridge needs at least 1.4 volts before it begins
to conduct. You probably just don't have enough signal for that.

Mark Zenier mzenier@eskimo.com Washington State resident

 

[Mark Zenier]

In article <1d207761.0411291705.3593de3c@posting.google.com>,
Jeff Pelletier <jeff@basetwomedia.com> wrote:

1) A real VU meter has a built in rectifier. (A copper oxide low voltage
one, I think).

And 2) a silicon diode bridge needs at least 1.4 volts before it begins
to conduct. You probably just don't have enough signal for that.

I was trying to plug it directly into a line-level output. From what
I've read, a "Hi-Fi" signal is 1.228 V DC (for 0 db) and consumer home
electronics are 0.316 V DC. Would this mean I'd require some sort of
amplifier?

Yes, (even if you have a real VU meter that's sensitive enough, they're
pretty low impedance and may load down your signal).

Mark Zenier mzenier@eskimo.com Washington State resident