Trip Points either voltage or current levels to trip a comparator

[Reloadron]

thanks for that, i will save it and print out, its not my computer so i dont get a say when it's suddenly formatted i keep most my stuff on usb stick but i have had one fail so i print the best stuff for my folder

When you are the "Little Ghostman" the big Ghostman rules.

Ron

 

[large_ghostman]

ONE DAY

 

[audioguru]

Do you have a Macintosh computer??
I got my first computer 19 years ago and it used a Microsoft Windows operating system. It and its replacements over the years could download PDF files and they used Adobe Acrobat Reader software (free) to display them. But I have never ever made my own PDF file.

 

[large_ghostman]

no we use windows, i can open PDF's but would be useful to be able to make them for printing out stuff and to archive it rather than use something like word.
apparently on dads work laptop he has a program to use, when he remembers what its called i will look at it

 

[audioguru]

I use Microsoft Paint program to copy and add things to a schematic (even if it is a PDF schematic). Then I save my schematic as a PNG file. I NEVER use Word for electronics.

 

[Reloadron]

We are getting off topic but I tried a little experiment. I converted the web link I posted earlier to a pdf format. The file should be able to be downloaded from here. Clicking on "here" should open the file and once opened in acrobat reader you can click File and Save a Copy. Guess I will see if it works. The file is on my web space.

Update: It works so LG if you want the pdf of that stuff have at it.

Ron

 

[Billy Mayo]

NOR GATE U10 only works when the input voltage was comparing Positive voltages, it didn't work when comparing Negative voltages, why?
I changed it and it works now

https://s1348.photobucket.com/user/BillyMayo1988/media/NORGATEpic1_zpsc29ae911.jpg.html?sort=3&o=0

https://s1348.photobucket.com/user/BillyMayo1988/media/NORGATE3_zpsdadbd16b.jpg.html?sort=3&o=3

 

[Billy Mayo]

What type of RC network is that , what does the Diode do? it discharges the cap?

 

[audioguru]

NOR GATE U10 only works when the input voltage was comparing Positive voltages, it didn't work when comparing Negative voltages, why?
I changed it and it works now

https://s1348.photobucket.com/user/BillyMayo1988/media/NORGATEpic1_zpsc29ae911.jpg.html?sort=3&o=0

https://s1348.photobucket.com/user/BillyMayo1988/media/NORGATE3_zpsdadbd16b.jpg.html?sort=3&o=3

 

[audioguru]

The schematics are the same. No change.

Why don't you know the function of a NOR gate? "When either or both inputs are high then the output is low. When both inputs are low then the output is high".

 

[Billy Mayo]

Why don't you know the function of a NOR gate? "When either or both inputs are high then the output is low. When both inputs are low then the output is high".

When you flip the Input polarity to an out of phase AC , the NOR gate wouldn't work , only when the AC input was In phase

Input AC Inphase = both inputs High and output low
Input AC out of phase = Both input high and output low also not high

Take a look at the schematic again

do you see the RC network with the diode on the NOR gates output , what type is this?
What type of RC network is that , what does the Diode do? it discharges the cap?

 

[audioguru]

When you flip the Input polarity to an out of phase AC , the NOR gate wouldn't work , only when the AC input was In phase

There is only one input signal with nothing to compare it to, to see if it is in phase or if it is out-of-phase.

Input AC Inphase = both inputs High and output low
Input AC out of phase = Both input high and output low also not high

The output is always low. Why do you say, "also not high"? Do you want the output of the NOR gate to be high?

do you see the RC network with the diode on the NOR gates output , what type is this?
What type of RC network is that , what does the Diode do? it discharges the cap?

It is a positive peak detector. The diode conducts when the output of the NOR gate goes high then the 10k resistor quickly charges the capacitor.
When the output of the NOR gate goes low then the 576k resistor slowly discharges the capacitor.

 

[Billy Mayo]

Why is their a positive peak detector? Without the diode what would make the difference? Having a peak detector does what for an RC network?

 

[Billy Mayo]

Inphase input has -0.7VDC on pin#12 of u10, pin#13 of u10 is +12.6 vdc . Output is 0.32

out of phase input has +12 vdc on pin#12 of u10 and -0.7 on pin#13. Output is 0.32

 

[audioguru]

Why is there a positive peak detector? Without the diode what would make the difference? Having a peak detector does what for an RC network?

The peak detector function uses the words "quickly charges the capacitor" and "slowly discharges the capacitor".

Telling us the voltages at the pins of the NOR gate is meaningless since we do not know its supply voltages.
We don't even know what the circuit is supposed to do.

 

[Billy Mayo]

how does the peak detector charge the cap faster?

ii thought the diode just clamps the voltage, but the nor gates out is always low , so what is it peak at?

u10 is vcc +13 and pin#7 is ground

 

[audioguru]

how does the peak detector charge the cap faster?
i thought the diode just clamps the voltage

I guess you do not know what a diode does and you do not know Ohm's Law. See my attachment.

but the nor gates out is always low

No.
The output of the NOR gate goes high when both of its inputs are low.

 

[Billy Mayo]

I understand what you said

What I don't understand is how is the diode a Peak detector? is it clamping the HIGH state voltage when the NOR gate goes HIGH?

 

[audioguru]

A silicon diode has a forward voltage drop of about 0.6V at low currents.
The output high of the NOR gate is about +12.5V and the diode voltage is 0.6V so when the capacitor is completely discharged then the voltage across the 10k resistor in series with the diode is 12.5V - 0.6V= 11.9V. When the output high at the output of the NOR gate makes the anode of the diode high then the diode is forward biased and it conducts. The capacitor is quickly charged by the NOR gate, diode and 10k resistor. The capacitor charges to a 11.9V peak.

When the capacitor is fully charged and the output of the NOR gate goes low then the cathode of the diode is more positive causing it to be reverse biased then it does not conduct and the 10k resistor does nothing. The 576k resistor slowly discharges the capacitor.

 

[Billy Mayo]

The capacitor charges to a 11.9V peak.

Their is the peak voltage , i get it now , so it does clamp the voltage

I wonder why they wanted to charge the voltage at 11.9 and not at 12.5 volts , any reason why?

It shortens the charging time it seems