Delta Pulse

[Great_Alex]

good points about T2&T3 and Sample .Thanks KT315 .

now i use 2.2 K for R5 but with large cioil i should reduce it .

i have a field test for deep target today ,i use 1m *1m coil with 8 turn winding and 2.2k ohm damping resistor first i use a 27 * 35 cm steel plate at depth of 1.5 meter , it detect it good i use 70% sens and 70% pulse power , the detector detect it very easy . when i increase depth of target to 2 meter in auto mode it detect it weak but in manual mode it detect the target better and more clear , I reach to maximum depth of my DeltaPulse up to 2.30m only in manual mode when i increased the TX power to max ; i didn't increase the SENS(GAIN) cause of a lot of noise that produced in high SENS(GAIN) . this test changed my mind about DELTA PULSE .

good depth results for me but the noise of my detector is too high and i have the ZERO PROBLEM yet.



best regards

[nelson]

Hi Alex.
Can you please tell me how you made the front panel?
I have a software to disign front panels, but i don´t have any idea of how to transfer the image to the panel material. Any ideas.
Regards
Nelson

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after i built the delta pulse it works well , it could detect a 2cm coin at 32cm with 25 cm coil ,at first the meter gage when it was calm and away from metalic object was around zero when detect a sample coin the meter gage increase to positive side and when the sample metal removed the gage go to negative but after 1 or 2 seconds it go back to zero position and balanced whit out pushing zero key , my delta fall into ground when i was testing the unit and it damaged , i check all the parts pcb and resodering and finaly found the D9 diode was crashed , i replace the D9 , and all of the iCs after this work the delta seems to becomes healthy but now when the sample metal removed the gage doesn't go to negative , i check the uA meter but it's OK , i don't know which one of this kind response is normal ,also the depth of detection decrease a coin in 20 cm .

the zero button doesn't work like the tune of other detectors like PS2 or lorenz , is it normal ?

what's the main reason for RANGE knob ( 500K ) , when i increase or decrease it obvious change in detector response not happen, what's the advantage of range of between 2 sample ?

best regards

[Great_Alex]

Dear Nelson

It's not so strange work , I draw the panel in autocad , after plot on Gloss photo paper i cover the paper with white transparent tape then i stick it with glue , i didn't print on the plastic directly .

regards

[kt315]

now i use 2.2 K for R5 but with large cioil i should reduce it .

people has suggested many times to reduce R5 value to 680 Ohm. low value is not so actual for PI detector with big Sample Delay time. you probably observe self coil resonanse first peak on O-scope and gotta the confuse... put 680 Ohm and share a picture again.

[nelson]

Excellent Alex and thanks for the information.
Regards
Nelson

Dear Nelson

It's not so strange work , I draw the panel in autocad , after plot on Gloss photo paper i cover the paper with white transparent tape then i stick it with glue , i didn't print on the plastic directly .

regards

[Great_Alex]

I change the 2.2 K with 680Ohm and the device become more stable but the depth didn't differ too much cause it make me use of lower preamp gain, in higher gain the DP absolutely overshoot and didn't work .

i change the 20K PULSE WIDTH pot with 50 kilo for higher pulse width for greater depth , a good choice it increase depth slightly but the Battery scream Heellllllllppppppppp and then the IRF840 ( i use IRF840 instead of 740 ) smoked , what is the best choice for more powerfull Mosfet with lesser inner resistance that could absorb 600V shock of back EMF , i see the Transistor that used in MDL pictures that michael sent was very big and perhaps very powerfull , any body know what's that ?

what is the best choice for increasing the Gain of DP , increase the gain of LF357 or add a secondary amplifire between LF357(IC 4) and TL062(IC5 A) ?

[kt315]

i use 1m *1m coil with 8 turn winding

try use standart coil for DP. 16 turns for 1m x 1m coil. you use absolitely improper coil and so get poor result. why you do all CONTRARY to common sense that the people had wrote here many times???

[Great_Alex]

first i use a coil with 1*1 meter and 15 winding but it was very unstable , i remember that the commerical detectors use lesser winding , i got best performance and stability in 8 to 10 coil turns , maybe you're right but i do all of that in my home and my home is near a RF transmittal center and very noisy .

i should make a new coil with higher turns and check it out door in next weekend if the rain allow me

the first part of 556 D1A has 50% duty cycle when it's off the main gate to VCO D10C was open , why ?what happened if the gate was always on ?

[kt315]

Alexander, is it this pix CLEAR for you or not? can you RECONNECT your wires according the pix?
I see your elecronic skill is very low, you must read more technician books.

[Giovan]

Coil

Good morning, i build my coil with 15 turns, it has 33,5 cm x 33 cm , it has all in pvc, But the sensitivity depends too of values of resistors and calibrate of the Delta Pulse i have detected an money at 18 cm , 20 cm , it is the best with my delta pulse.




Thanks
----------------------
From Brazil

[perdica 2]

hi

i want to design big coil for delta pulse and i have simulated coil parameters
and i see changes in the pulse (like a self-oscilation) i don't now

can someone tell me whwt couse this changes like in the picture

https://www.geotech1.com/thuntings/a...1&d=1230151374

[perdica 2]

better picture
http://www.servimg.com/image_preview...=17&u=12558588

[Geo]

Try to use a 1mH coil. Original coil is 1.1 x 1.1 m 16turns. After coil construction you must play with damper resistor. If you leave the frequency at 100Hz then the existing 2k2 is OK.

[Geo]

Good morning, i build my coil with 15 turns, it has 33,5 cm x 33 cm , it has all in pvc, But the sensitivity depends too of values of resistors and calibrate of the Delta Pulse i have detected an money at 18 cm , 20 cm , it is the best with my delta pulse.




Thanks
----------------------
From Brazil

You need more more turns for a 33cm coil !!!!!!!
Calculate it for 800 ... 1000 uH

[Geo]

first i use a coil with 1*1 meter and 15 winding but it was very unstable , i remember that the commerical detectors use lesser winding , i got best performance and stability in 8 to 10 coil turns , maybe you're right but i do all of that in my home and my home is near a RF transmittal center and very noisy .

i should make a new coil with higher turns and check it out door in next weekend if the rain allow me

the first part of 556 D1A has 50% duty cycle when it's off the main gate to VCO D10C was open , why ?what happened if the gate was always on ?

Hi Alex. You make a big mistake.....
You cant check a 1x1 m coil in the lab there are alot of erratic signals. I can check in the lab only until 50x50 cm coil. If it is bigger then detector is very unstable.
What wire do you use at the 1x1 coil ????? For me it is good to be 1 mm at least.
Regards