Analysis this schematic

[Davor]

All of the diagrams show highly dampened coil response. Try some higher resistor values until you get ringing, then reduce it for some 20% and that's it.

[mohandes]

CLASSIC! you do not wish to read the forum! this is your problem!
[ATTACH]26110[/ATTACH]

Hi can you put the link.kt315
thanks mr 6666.

[6666]

mohandes



I received your PM, and will answer here.
I am not exactly sure what you are asking me, but you seem to be asking about the DC off set, and the coil damping resister.

Firstly to set the DC off set on the 5534, I assume that you have a correctly made coil connected.
place the coil away from all metal,
place the negative probe of a digital multimeter on ground, and the positive probe on pin 6.
Now adjust the offset to zero volts.

With the damping resister, what the animated graphic above in post # 226 is trying to show you is as the damping resister gets closer to the correct value, the ringing stops.
To try this put the ground wire of your CRO probe on ground of the pcb
put the probe on pin 6.
Now start with a high value resister say 1K
you should see some ringing, now work down in value till you see the ringing stop.
I hope that helps you.

PS empty your mail box I cannot PM you.

[kt315]

CLASSIC! you do not wish to read the forum! this is your problem!

[mohandes]

hi all
gurus it is very interesting and wonder for me.i set FCY-PPs on 135HZ and next measure pin3 ne555 and pin6 5534 by oscope.
look at the pics.yellow is 555 and blue is 5534.
just tell me why dont creat the correct figure like oscillogram.
HELP PLEASE OR GUIDE ME(attention to the WIDTH in the figures)
regards

[mohandes]

I COMEBACK

hi all gurus
now i have digit scope and can measure all time.
ok.
i adjust all oscillograms but can not set pin6 5534.I replace resistors (100ohm,120ohm,150ohm,180ohm,220ohm,330ohm,470ohm) but that wave(in oscillogram) dont make,,why?
who can explain me? i set pin6 5534 on -0.27volt and (nearly 0)and measure that.

please tell me?i use two coils and both of them not ok.
thanks

[Davor]

This is a PI project so self-resonance of the coil is dampened by the damping resistor. You'll find the best value by experiment. The best wire for the coil is litz wire, which means something like loudspeaker wire with many strands, just like in your link, but every strand insulated. Second best is a wire just like in your link, but all strands tinned (white metal).

[mohandes]

hi my freinds porkluvr ,davor and ...
sorry me ,becuase these days i have exam and can not measure psg,but i have a question,what dose value of the frequency the coil ?(point of parallel res and coil connecting)
can i make the coil 1m*1m ,450-500mkh, 1.2-3ohm resistor?(by tel cable beter or Copper wire orhttp://www.geotech1.com/forums/showt...Legend-1/page3 number 53)or i say better this : for make the coil which metod is better ?
regards

[porkluvr]

check itmy friend porkluvr.
what do you think about saying mr kt315.?good i put resistor 180ohm (or 150ohm) ?or decrease coil to 300mkH?
i put picture for your request tomorrow becuse i take film

NO MOVIE. Still pictures only. DC coupling. I will bend on wanting to see U1-3 at the same time... you can leave that off. But AC coupling for what I want to see is wrong wrong wrong.

You need to NULL the U4-6 output and from your hand drawn picture in #213 it is unclear (but it looks wrong).

Maybe your coil and damper resistor should be changed but you must worry about that only AFTER you get U4 compensation and null properly adjusted.

[inio_01]

Hello "Guru" Mohandes
Good work, advice from me as you will have something soldered, first try to solder to the PCB component and then cut the rest of the elements (wires) near the PCB, to cut, you can use a good quality special side snips or you can use nail clippers (medium size). The controls would be better to use a flexible multistrand wire (also not too long) than wire phone cord, you can save a lot of nerves when moving or when the electronics will be packing into the housing. Regards

[georgi.g.zhelev]

mohandes ,Very bad installation, very long wires. MAKE short wires, ok? NE 5534 is no OK!!

[kt315]

DO NOT LOAD MY PM BY YOUR QUESTIONS. BUY THE BOOK INSIDE THE METAL DETECTOR AND READ! RTFM!

[mohandes]

check itmy friend porkluvr.
what do you think about saying mr kt315.?good i put resistor 180ohm (or 150ohm) ?or decrease coil to 300mkH?
i put picture for your request tomorrow becuse i take film

[kt315]

......

[kt315]

11 --->>>>> decrease the damper resistor value.