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Analog Period Detector

S

Spehro Pefhany

Jan 1, 1970
0
Wow....That's like comparing a signature with a signature..

Using a PIC or DSP are great hardcore solutions.. Arrrff! Arrfff! :)
Sometimes I think I should force myself to use micros more often and
learn DSP programming just be skilled in those areas..

If I keep using the old stuff like the 4046, I don't think I'm getting
the best experience..I just stay dum with the dum stuff...
However...
I'll have the 4046 working wayy before the time it'll take me to learn
DSP programming. :)

D from BC

You could use the dsPIC, slap in an FFT routine, and you're almost
done. Longer than wiring up the 4046, but not insane.



Best regards,
Spehro Pefhany
 
D

D from BC

Jan 1, 1970
0
You could use the dsPIC, slap in an FFT routine, and you're almost
done. Longer than wiring up the 4046, but not insane.



Best regards,
Spehro Pefhany

Phsssttt...(spits out coffee...) omg! There's a dsp in the PIC now...
fkn new shit coming out all the time!!..
I don't know anything anymore...

If I was a wiz at programming, yeah...I'd go PIC but I'm out of
practice..
My programmer has lots of dust on it..
D from BC
 
D

D from BC

Jan 1, 1970
0
How about this:

A multiplying PLL makes, lets say 8 times the frequency.

A 4051 constructs something like a sine wave that is fed to one pin on
a window comparitor.

The other pin of the comparitor is run from the signal.

A cd4017 is reset if the window comparitor indicates an out of bounds
signal. The clock of the 4017 runs from the divided VCO output and it
is disabled if it hits state 10.

I had to look up the 4051..

I'm not sure if I got this...

So a 8 to 1 analog demux creates a single Vref from one of eight
Vref's.
The window comparator uses the Vref(xof8) to see if there's a match.

My guess is that 8 points are tested along the waveform to check for
anything different than expected..

The 4017 acts as a "pass" test point counter.. 8 "passes" and the
wave match's. Green light..
Any failed points and the counter is reset. No green light..


D from BC
 
R

Rev. 11D Meow!

Jan 1, 1970
0
I don't know why I though this was going to be a SPAM ad for tampons.
 
I had to look up the 4051..

I'm not sure if I got this...

So a 8 to 1 analog demux creates a single Vref from one of eight
Vref's.
The window comparator uses the Vref(xof8) to see if there's a match.

Eight different static voltages - presumably set up by eight 19mm 15-
turn trimming potentiometers - selected one after the other by the
4051.

If you got for one of the 19mm potentiometers that has a transparent
top, the positions of the wipers will provide the visual equivalent of
a coarse scope display. Farnell stocks the Bourns 3006P-7 (the order
code for the 10k version is 935-2295 and they cost about $2 each in
small quantities).

<snip>
 
M

MooseFET

Jan 1, 1970
0
I had to look up the 4051..

I'm not sure if I got this...

So a 8 to 1 analog demux creates a single Vref from one of eight
Vref's.

Yes, perhaps with a bit of smoothing.
The window comparator uses the Vref(xof8) to see if there's a match.

Actually that active sense is mismatch but I'm sure youve got it.
My guess is that 8 points are tested along the waveform to check for
anything different than expected..

Yes it would test for distortion and if the PLL isn't locked, it would
also give an indication.
The 4017 acts as a "pass" test point counter.. 8 "passes" and the
wave match's. Green light..
Any failed points and the counter is reset. No green light..

Its 10 passes, not 8 but other than that spot on.
 
J

Jamie

Jan 1, 1970
0
D said:
Ooops ..there's another detail I should have put in my OP.

The circuit has to work on a bridge rectified sine wave signal.
I understand the off phase detect method. However, I think that's best
for sine waves.
D from BC

Ok then,,
Do as I did once, pass the signal through Flip Flop to get a
clean square wave. Use this signal to synchronize a 555 one shot
timer. Use the ending cycle along with the in coming square wave
to drive a gate which will give you a +/- pulse to make adjustments.
Of course, this could be done very simply in a PIC/AVR mini also.
 
M

Michael A. Terrell

Jan 1, 1970
0
Spehro said:
Heck, use a small 32-bit ARM. PICs and AVRs are so last century.


I thought they were last millennium?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
 
S

Spehro Pefhany

Jan 1, 1970
0
Ok then,,
Do as I did once, pass the signal through Flip Flop to get a
clean square wave. Use this signal to synchronize a 555 one shot
timer. Use the ending cycle along with the in coming square wave
to drive a gate which will give you a +/- pulse to make adjustments.
Of course, this could be done very simply in a PIC/AVR mini also.

Heck, use a small 32-bit ARM. PICs and AVRs are so last century.


Best regards,
Spehro Pefhany
 
D

D from BC

Jan 1, 1970
0
No, No, No. A 4004, a PIC is to complex / powerful for that task.

4004???
Intel's first MPU from 1971 with a clock of 108khz??
Ha ha ....funny.... :p

I've come up with a new design with 2 D FF's and 2 op amps.
It'll be a 2 IC project.
I might squish it down to a PIC someday..
D from BC
 
M

MooseFET

Jan 1, 1970
0
4004???
Intel's first MPU from 1971 with a clock of 108khz??
Ha ha ....funny.... :p

I've come up with a new design with 2 D FF's and 2 op amps.
It'll be a 2 IC project.
I might squish it down to a PIC someday..
D from BC


Get someone to make you a chip with two op-amps and two flip-flops.
 
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