Delta Pulse

[Noemio]

Hi

I need help

I feed voltage in false diversity to my machine while charging.
battery is our of order now.I got new one but my delta is not working
it's TX part is okay.cause can measure 500volts at coil .but no sound at all

I also built new delta but 2k2 resistor burnt at first trial.and there is no sound at this new one too

is teher anyoffer to find fault .
I want to repair on of them
best regards
Okantex

Despite what you say, it seems to be something on tx stage. I think your pulse with (TR3) is too large; the maximum value should be no much more than 400 µS. Are you able to test it (have you got an oscilloscope)? Try to verify values of C3 (10nF), R4 (5,6 Kohm) and P3 (20 Kohm).

[okantex]

Hi

I need help

I feed voltage in false diversity to my machine while charging.
battery is our of order now.I got new one but my delta is not working
it's TX part is okay.cause can measure 500volts at coil .but no sound at all

I also built new delta but 2k2 resistor burnt at first trial.and there is no sound at this new one too

is teher anyoffer to find fault .
I want to repair on of them
best regards
Okantex

[nelson]

Test Points

Hi. I just had finish my second Delta Pulse. For that i use some old and some new components.
Now i need the test points to check them with the scope.
Regards
Nelson

[Max]

Thank you so much KT315, but now I'm much more confused :

"...the working frequency must be ABSOLUTELY PRECISELY 100 PPS. or what you have industrial frecuency multiplied by TWO..."

and

"...Multiples of the power frequencies also had to be avoided e.g. 100 or 120..."


I apologize because my English is not so good, but the phrases seem to be discordant!
The second sentence should mean that neither 50 Hz nor 100 or 150 or 200 ecc.. are suitable frequencies.
Am I wrong in something?

TNX again

Hi,
indeed is really easy thing.

Eric Foster explained why you have to avoid exactly put the MD in the multiple of mains frequency, whatever it is in your place... 50 or 60Hz.

Now, you have to know that many people made actually good PIs using very standard frequencies like 100Hz or 400Hz but there's a drawback: these MDs tuned at that p.p.s. rate are often influenced bad way by power lines.

Myself built many of these... tuned to that frequencies too and got actually noise from power lines during e.g. testing on the bench, but just sometimes, not always. Depends on the amount of noise you have around... the more the noise from e.g. power electrical motors etc and you'll be more and more annoyed by that erratic signals...

I have to say that often that same detectors tuned at e.g. 100 or 400Hz are very performative outdoor in open space, farm land etc... far from electrical noise.

You must also know that people like Eric Foster give the ability of changing e.g. 10% more or less the frequency of their PIs: an example is deepstar that runs at 3Khz with a tolerance of many hundreds Hz you can set by a control knob... just for the purpose of minimizing external noise interferences.

In Delta you're expected to use it at 100Hz... you can , and it works good outdoor most of the times. But you'll better set something 120Hz if you have 50Hz mains frequency... or 150Hz if have 60Hz mains frequency... that way you'll get it works better in about all situations.
Another interesting frequency is 400Hz (XR-71 is that way) you can choose 420Hz or 470Hz and works too (I would say even better).

Important is understanding that , sometimes, this is not enough... and if you have big power stuff around (e.g. radar stations, ELF, VLF stations, cables in the ground etc etc etc) your MD will simply fail... no matter which frequency you'll use... cause too much electrical noise around.

Kind regards,
Max

[kt315]

Noemio, you can certainly set ANY frequency. but then you will get MORE noise and unstability on freq=/=2*50*N.

read pls a mention http://www.metaldetection.net/english/DeepersMF-En.htm

the DEEPERS MF Model 2008 can be adjusted to 400 different frequencies ranging from 550 Hertz to 950 Hertz. This allows you to fine tune the instrument to your particular hunting needs. Eliminate mineralized ground and electrical interference and maximize your chances of success. It's the more powerful detector of our production.

or do you wish minimize your chances of success?

[Noemio]

4538

Thank you so much KT315, but now I'm much more confused :

"...the working frequency must be ABSOLUTELY PRECISELY 100 PPS. or what you have industrial frecuency multiplied by TWO..."

and

"...Multiples of the power frequencies also had to be avoided e.g. 100 or 120..."


I apologize because my English is not so good, but the phrases seem to be discordant!
The second sentence should mean that neither 50 Hz nor 100 or 150 or 200 ecc.. are suitable frequencies.
Am I wrong in something?

TNX again

[kt315]

---quote---
Hi John,
Here is a copy of a post I made a couple of years ago which deals with this subject.
RELEVANCE OF PULSE FREQUENCY in a P.I. DETECTOR.
A question that is often asked about P.I. detectors is the relevance of the pulse frequency. Some detectors run at a hundred or so pulses per second while others run at several thousand. The first archaeological detectors I worked on ran at 22 p.p.s. In later versions we upped it to 43, then 170. The important thing was to avoid the same frequency as power lines, 50Hz in the UK, 60Hz in the US. Multiples of the power frequencies also had to be avoided e.g. 100 or 120. Severe beat note interference would result if the detector and power frequencies coincided; that is if you were anywhere near power lines as is often the case in the UK.
P.I. detectors running at low frequencies usually pulsed high currents through the coil, 5 - 10 amps being a typical figure. The on / off time ratio of the pulses was high so the average current drawn from the battery would be 100 - 200 milliamps.
Many of todays detectors favour much higher pulse frequencies. This puts the detector well away from power line interference but low frequency radio transmitters can then start to cause problems. Faster pulse rates also have the advantage in that the response of the detector can be made more rapid, which aids in pinpointing an object. Fast pulse rates require that the pulse current be less, otherwise things would start to run hot and the battery life would be rated in minutes. The pulse current can be restricted by a lower transmitter voltage but more usually by a resistor in series with the coil or by making the coil more resistive by using finer wire. 0.1 - 1 amp pulse currents being typical. One major factor in determining pulse current is acceptable battery life. With rechargeables 5 - 10 hours is OK, while standard alkaline cells would be expected to give 15 - 25 hours for the cost to be acceptable. One or two recent detectors on the market appear to have energy recovery circuits which make the transmitter more efficient and significantly increase battery life.
The pulse frequency has little effect on detector performance; one running at 170 p.p.s. could have the same range as one running at 5000 p.p.s. but there are many inter-related factors that determine the final performance, not least the design of the receiver circuit.
Hope this helps. I favour higher pulse rates (1500 - 5000) in my current designs.
Eric.

[Noemio]

4538

Hi all,


Since I was not able to find a couple of 4538 , I used a 4538 for U2 and a 4098 for U3.
This results in a different pulse duration on T4 and T5.
The outcome of this may be the cause for which the device is not working?
In this case, is it possible, therefore, that even 4538 from different manufacturers used together on this circuit may produce enough magnitude in different pulse duration to compromise detector functionality?


Not sure, moreover, why KT315 refers to industrial frequency:

"...the working frequency must be ABSOLUTELY PRECISELY 100 PPS. or what you have industrial frecuency multiplied on TWO. if you have 60Hz than you must have 120 pps..."


Anyway, for 50 Hz, working frequency could be even 150 or 200 Hz?


TNXE6

[erolunall]

http://www.teknolojiekibi.com/yeni/index.php?topic=1180.0

LCD circuit for delta by elbombacı

you can find all infoo savefiles link on first mail

Regards
Erol

[kt315]

a device has been priliminary checked and tested. mainly at lake. a place with something metalic at lake bottom was been observed. a device was enough stable.

HH

[Mullihaka]

Dumping resistor value, noise pot problem?

I have a 27 turn, 25cm diameter coil of 0.5mm enamel insulated copper wire. What would be a good value for the dumping resistor? I started with 2k2, added another, then third in parallel. I couldn't find any difference in the detection distance in the air. It's about 20cm for 2euro coin.

The 20k noise pot can only be turned only tenth of the turn, otherwise the FET remains on most of the time, the duty cycle being close to 95%, measured at the gate of the FET. Can this be caused by ringing of the coil due to too high dumping resistor value?

All hints appreciated.

[nelson]

Hi my friend and thanks for your big contribution to the forum.
Indeed has many of us, i was looking for an LCD to this detector, so this looks good to me and i knw to many members here.
Best regards from Santiago, Chile.
Nelson

You can reach LCD circuit for Delta Pulse from this link.

http://www.teknolojiekibi.com/yeni/i...p?topic=1180.0

[Uykusuz]

You can reach LCD circuit for Delta Pulse from this link.

http://www.teknolojiekibi.com/yeni/index.php?topic=1180.0

The Miner 4 should enter Demo Mode after running 1 minute without Coil.
(Thats what the manual says, i dont have one).
If you have more Questions, please create your own Thread, this one is about Delta Pulse.
Good Luck with your Project.

[Max]

Hi evryone , i have a question . two years ago i made a metal detector.
name it is miner 4 . it is germany of metal detector . i made it without
coil . but my miner 4 trun on and lcd show stage select language (eng / germ)
when i choose a language and press enter key lcd show nothing and i must restart metal detector
and replay job and restart metal detector . i was cunfused about this problam .
do you know information about this metal detector (miner 4) & problam me ?
thank you

Hi,
I don't know about it... but, have you tryed with a coil there ?

If the MCU check for some signal and the absence of coil would suppress it... you'll probably get such kind of behaviour... device froze waiting for something that never happens...unless software developer made proper error handling for that... that seems unlikely.

Try to test with a coil... if you didn't already, probably it will work.

Kind regards
Max