Is Pulsedetektor.de for Hobby Builders???

[amtech2005]

Here are my reasons for complaining !!!
Before I post this thread , this is not to slander anyone but to recieve proof of un-answered questions for many years !!!
1. Why are field tests of the models you can build not published ?
2. Are field tests available from your commercial units ?
3. I never see any prices on anything !!
4. What is the truth on PIU modules. Hobby or Commercial Only ????
5. How dependable are the Traco-Power modules . The 3 that I have circled are close to $100 u.s. dollars !!Are they dependable .
6. Is your Market only in Europe ??
7.The Honest difference between "Project Circuits" And the one's only that you can buy !!!
I have heard of several Pulsedetector units being built and having very bad results. So please if the Owner or administrator of pulsedeteektor can answer the above questions with "HONESTY" and not go around in circles , this would be great !!!Sometimes the truth can carry a ton of hidden knowledge and wisdom. Polite and Courteous answers are Welcome........Thank-You ....Eugene

[1843]

Hi Eugene,

I made the above unit some months ago.... and lost a lot of time and money...and at last I hammered it.

I don't know why some people enjoy when others get pain....


Thanks,
1843

[Aziz]

Hi Eugene,

what I have found on this site are lots of interesting circuits using AVR chips. Maybe, I can use some tricks for my own AVR PI project.
But I would never use any
- DC/DC converters (causing too much noise)
- IGBT switching FET and IGBT driver for the TX stage (IGBT's are quite slow)
- CNY17 (slow optocoupler) for the TX switching signal, but OK for the audio stage coupling
- only one RX amplifier stage

Maybe, the projects are not designed well. The internal A/D converter of the AVR chips can only sample up to 15 kSPS (max). This is quite unsufficent (10-12 bit resolution) for the PI front end and some stages should not be made in digital technique.

Otherwise interesting site. But I wouldn't build the projects. The projects are giving not much performance which should persuade someone to buy the professional versions.

Regards,
Aziz

[1843]

But I would never use any
- DC/DC converters (causing too much noise)
- IGBT switching FET and IGBT driver for the TX stage (IGBT's are quite slow)
- CNY17 (slow optocoupler) for the TX switching signal, but OK for the audio stage coupling
- only one RX amplifier stage

I am in agreement with you! but what do you want to do so as not to use any DC converter?

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I think that the bad Miner designing causes a lot of damage to the ADC. The IC7 output swings between (-3.5V) to +3.5V while the absolute maximum rated voltage for +input of ADS7816 is (-0.3V) to Vcc +0.3V...

What do you think?

Regards,
1843

[Geo]

Maybe, the projects are not designed well. The internal A/D converter of the AVR chips can only sample up to 15 kSPS (max). This is quite unsufficent (10-12 bit resolution) for the PI front end and some stages should not be made in digital technique.

Otherwise interesting site. But I wouldn't build the projects. The projects are giving not much performance which should persuade someone to buy the professional versions.

Regards,
Aziz

OK, i agree. For me the problem is why they write at the site that the detectors have very good performance?????
ATINY4 says that have a max detection distance 2.8m with 28cm coil. I said.. if it has 2 m with 28cm coil is very good so i constructed it.
Results.... very bad. If i remember right it detects a coin at 25... 30cm max and one metal door at 1.5m. So DeltaPulse without exotic components is better. Also ATINY was not stable
I lose a lot of time to wait the exotic components order and to construct it
Regards

[Aziz]

I am in agreement with you! but what do you want to do so as not to use any DC converter?

Hi 1843,

this is quite trivial and very elegant with low noise power supply for analog part:

Battery connections: +Ub, -Ub

Analog power part:
First stabilizing the power supply from battery +Ub into +10 V.
Then dividing the +10 V into +5 V (AVdd), 0 V (AGND) and -5 V (AVss). AGND is a low impedance virtual ground for analog signals (= +10 V/2).
+5 V = AVdd = +10 V potential to -Ub
AGND= 0 V = +5 V potential to -Ub
-5 V = Vss = -Ub (0 V potential to -Ub)


Digital power part:
Digital part has its own regulator of +5 V (DVcc) to -Ub potential (DGND). Digital ground is not the same as analog ground! Care must be taken!


Coils:
The transmit (TX) and receive (RX) coils must be galvanic decoupled. So, I need two coils: TX and RX. The coils have its own shielding potential: TX has -Ub, RX has AGND. Of course, they must not connected together.


DGND and AGND on A/D converters:
Sometime, there is a need for A/D conversion. The analog signal is swinging between 0 .. +10 V referred to DGND or -Ub. In this case, it is better to take a second decoupled analog power supply for A/D converter to minimize further noise (AVdd2, AGND2). The original analog signal (-5V .. +5V) must be divided by two or level shifted and must be seen as a unipolar signal ranging between 0.. e.g. +5V referred to AGND2 or DGND. The software will see this range as a bipolar analog signal from e.g. -5V to +5V.


Regards,
Aziz