Voodoo Main Discussion

[SilverSurfer17]

What crap are you talking about ?

[billr]

How long is the forum willing to accept this crap and moreover what advantage is it to the majority that what to learn?

[billr]

[ATTACH]54439[/ATTACH]This is tp2 and tp3 it looks backwards and still not even close on the damping curve

You need to increase the voltage by 2 times at source to stabilize the output. Power fluctuations can create an erroneous effect on scope readings at certain times. Have you got a 24 or 36 power supply?
I had the same result and once connected to 38 volts or more but not above 50v it calmed down the output effect to what I expected to see.

[surfdetector]

[ATTACH]54439[/ATTACH]This is tp2 and tp3 it looks backwards and still not even close on the damping curve

What coil do you have connected?

We are unable to see the whole waveform as your time base is set to just 10uS

[SilverSurfer17]

This is tp2 and tp3 it looks backwards and still not even close on the damping curve

[SilverSurfer17]

I got my parts today got the board working again i put the hook on TP5 the other hook on TP2 as soon as i touched the clip of prob from TP5 channel 1 to TP1 it cut off the power supply and the voodoo removed it and it went back on so it was shorting it

[billr]

LOL Carl
Brutal......but true

[SilverSurfer17]

Once i get one working. I won't be posting as much. Im known as tangent Tom for a reason.

[Carl-NC]

SilverSurfer, I'm tempted to pay you 10c for every comma or period you use, but I'm afraid you'll start posting in Braille.

[SilverSurfer17]

Yeah i see that now but thats also why I'm here to learn something new besides the little i do know i knew i could get a board to kinda work but tuning it and making the best coils for that detector and learning their relationship i would have to learn also the programming part i always cringed at because of the dos base typing part of it thats why i do like this Mikro P its copy paste and GUI based and has a nice help and search feature so i wont lose interest in trying to figure it out or watching the 25 videos each over 1 hour and 35 minutes long lol

[Carl-NC]

Bizzaro world where the positive of a battery is the ground

This is common in the world of PIs that use low-side (NMOS/NPN) switches on the coil. It simplifies domain voltages but you gotta be careful when using a bench power supply combined with an oscope or a programmer.

[waltr]

"Ground" should really be called "Reference" since this is the node that all measurements are referenced to.
If you think of it this way then all makes better sense.

Many have had issues using bench power suppllies for detector circuits.
First issue is 'earth grounding' and shorts when using the scope.
Second is noise coming from or through the bench PS.
Third is current surge and flyback issues.

I and many others use a batter to power the detector circuit. This way the power is isolated.
I use a 3 cell LiPo battery with a 40W automotive tail light bulb in series as a current limiter.
Then when (not if) you mess up and short the power, the bulb lights and limits current to about 3-4Amps and nothing blows up.
This has saved me more than a few times.

[SilverSurfer17]

Ok George those clips go to TP1 and the test points are the hooks got it and yes I've never heard of virtual ground my brain is stuck in automotive 12 volt and the only thing I've ever used a oscilloscope for was fuel injectors in school 3 decades ago because i learned how to just use a noid light and never needed a scope after that so when i saw those clips where ground and it was using 5 volts i went right for the 5 volt ground

[billr]

http://www.lowgif.com/view.html

[Qiaozhi]

So then when it says tp5 channel 1 the hook goes on tp5 tp2 channel 2 tp2 is the hook and the both ground alligator clips go tp1 which is actually a positive ?

When it says channel 1 is connected to TP5, and channel 2 to TP2, this means that the earth clip is connected to TP1 (GND).
Some circuits (but not Voodoo) have more than one "ground", depending on which signal you're measuring. There is even such a thing as a virtual ground.