IF YOU HAVE MAKE , TRY THIS .

[Max]

I think 7660 can't supply 11-12 IC current.

aboyt GS4 power , I test , this work very good.I need one power supply like this for negative voltage.

Hi,
you can reverse diodes and caps polarity and get a negative voltage from it.

I mean the caps and diodes after the 2 complementary transistors collectors junction.

Look at the picture below to get an idea of polarity... but then apply this on the transistor stage of a GS4-like generator to have more current available.

PS: I remeber that GS4 voltage converter run at something 10s KHz and so you need shottky diodes and low ESR caps to get the best from it.

Best regards,
Max

[Qiaozhi]

i have a problem in my schematic . see picture , must use one level voltage between atmega8 and 4051 so use CNY17 but CNY17 out pulse is with delay and not clear , i busy for this.

can somebody help me , i need negative voltage converter like GS4 power.
GS4 converter voltage is good but this is positive and i need negative.

Hi Sisco,

This is the simplest circuit I can come up with that will do the job.
Please see SPICE netlist attached and waveform file.
If the 4051 cannot handle the waveform going negative by about 700mV, then simply apply an offset voltage of 700mV to the anode of the diode.
Hope you can understand the SPICE netlist. If not, I'll create a quick schematic.

[saeed_h]

Hi sisco
can you describe the COIL you used for minipulse3 ?
for example : loop diameter , turn numbers , wire type , ...
thanks
bye

[1843]

Hi 1843,
found that 1st delay is 150uS, not good for me.

Kind regards,
Max

Hi Max,

Where did you find that 1st delay is 150us? Its maximum 1st delay is 120us!!

It is within 40us to 60us, not more.

Best regards,
1843

[Unregistered]

Hi,
yes AD and OPA are generally speaking more expensive... than older and easy stuff like TL0xx.

I suggest TLC2262 (that is very cheap) for amplifier/integrators section.
You could use also older stuff for this like LS404 (quad low noise, very cheap now but obsolete) MC33079 (very good, cheap quad) or also TL074 (quad) or TL072 (dual); also TL084 and TL082 are fine for test like TL074/72.

I don't suggest using NE5532, dual version of 5534 cause one ic need 6mA of current and seems very much respect to the others e.g. TLC2262 (muche less current required and similar performances).

For preamp. I'll use good one OPA37 is very good one, you made good choice with it.

You can use also 5534 or lf356/357 for preamp... but OPA is better if you can find/buy it at a reasonable price... 11eur each is very expensive !

Kind regards,
Max

Hi there
If you had the money what opamp would you buy and use for the preamp and the integrator stage (dual opamp)
thanks
henry

[Broken Diamond]

Need Help About Elements

Hi Dear Sisco
I wanted To say thanks Again For Your Nice Project "MinipUlse 3"
I'm trying to make this For My Final Project Of University And I'm working to Finish It.

Please Help me about the "Function Of each element" ?? in this MetalDetector....i Need to explan them to my master and honestly i don't know...
for example you said: R42 with R49 adjusting the Lcd Contrast, or X5 is led LCD Connector....
Please Help with This, and write the function of all parts and elements.
I'll really get in trouble if i can't explain them
I Really Appreciate
Thanks

[sisco]

Hi ,

I absent near six month because I change my job and very very busy so

could't follow this object and forget many things about this project.

about : r42 and r49 this only for LCD setting (chracters lighting)

X15: for LCD inside light diode (you can don't use)

about "function about each element" , this is Physicochemical object.

example : best delay for detect gold : ~ 18us after off pulse coil

but in this delay can't detect iron

or best delay (max sensivity) for detect silver : ~ 55us

but in this delay can detect gold and iron

see this picture (this is for 7 month ago):

you must follow this method if you have free time.(this is very easy if you can work with AVR)

[Unregistered]

Hello Mr. Diamond

The circuit consists of the following main components: Tension ruling part U1 + U9 pulse-hurry U11 + Q1 amplifier and Sampler U3 + U4 + U5 integrator and amplifier U8 tone generator U6 + U7 control U12 + LCD 16x2 the operating voltage over X1/ L1 one puts on. L1 has to compensate the task the starting current from c1 to. C1 represents a short-circuit in the einschaltmoment for the Akku and reduces practically the river to the internal resistance of the Akkus. This can disturb additionally the PowerOn RESET of the processor. This is avoided by the hastening after river of L1. D1 takes the negative voltage peaks of the current supply, enstehenden by the secondary field. Since a festverdrahteter Akku is intended without an additional polarity diode in the entrance was done. The diode would bring a voltage drop additionally to L1. The p-MOS Q1 is switched from U11 and drives the coil. The Surpressordiode D3 limits the peak on 400V. G 1 dampens the coil. The pulsbreite and thus the achievement (power) with R53 are stopped. There the coil an inductance is has we it with a hastening after river to do. The longer thus the coil stream over Q1 lines up the more rises it. This procedure lasts so for a long time to the coil its inductive part loses. Afterwards we have it with a d.c. circuit consisting of internal resistance of the voltage supply - drain/SOURCE resistance of the p-MOS and d.c. resistance of the coil to do. The maximum pulsbreite must be ever smaller than this saturation point. Everything which beyond it goes can we as heating mat designate. Besides range and sensitivity decreases drastically. The measuring signal is supplied to the operation amplifier U3 by way of R5 /D4. At the same time by Q2 the peak-dependent sync signal for the processor (U12) is won. U12 supplies ensprechend programming the multiplexer U4 palpation impulses. The groped measuring signals are supplied to the integrator U8-1 by U4 and strengthened with U8-2. The reinforcement (Gain) can be varied with R51. The strengthened signal is supplied to the tone generator (VCO) by way of R40 consisting of U6/U7. By the potentiometer R50 that threshold value and/or operating point of the tone generator is determined. At R39 the signal for U12-ADC5 is measured. The processor digitizes the measured value and represents it on the 1.Zeile the LCD as bar graph and on the second line (right) as numerical value 0 - 1000. The potentiometers Range(Bereich) and Power(Leistung) are supplied to the processor A/D transducers immediately. The Aquisitionszeit when change lasts ca.5 seconds. In consideration of the measuring rate every 5 seconds a conversion is accomplished here. The free haven PC2/ADC2 (X9) does not find operation in the software. That is for mentioned all digital signal processing. Here the Gainpoti is replaced by a Stereopoti and communicates to the software the current reinforcement. In expectation which I find to time the software extend can who want the Stereopoti to insert. In the current supply 7805 is inserted thereby an LCD with lighting to be inserted can instead of the 78L05. The trimmer R44 Akkuspannung is to be adjusted as follows: Set please the processor only after attitude into the base. No concern it cannot happen to anything the breakdown diode D2 limits the voltage dividers on 4.7 V. The loaded Akku and at U12 haven C4 Pin27 fairs switch on. With numerical control Akku to 1.2 V (zellenspannung) trims and with Ni-MH to 1.25 V adjust. Wars. Contrast trimmer R49 on ` which you look ' adjust. Who a safety device to insert wants should in any case automotives safety device use. Those are low-voltage safety devices like one them from the car know. X13 is to be provided after programming with a Jumper. The RESET entrance is put thereby on the positive tension.

Some help ?

[Broken Diamond]

ThankS

WOW.
Thanks a lot Sisco.
It was a big Help.
I have a few More Questions but need to study Somethings Before Ask Them...
This is a really good project.
thanks

[Unregistered]

better than lf357 for more slew rate

the ad744 is better than any auther amplifier for pi
link http://www.analog.com/UploadedFiles/...eets/AD744.pdf

[sisco]

broken diamond , see this example .

can help you.

in this example :

freq = 1Khz
coil pulse wide = 200us
delay = 19us
samp pulse wide = 38us
inter delay = 75us
ground pulse wide = 38us
off pulse = 630us

for freq 1000Hz = period is 1ms (1000us) so =>

200+19+38+75+38=370us-1000us=630us

important in these timing is "delay"

you can programming your minipulse with this program and work.

[Broken Diamond]

Data Logger

Hi Dear SISCO,
Good points. Thanks for that.
But Now I'm thinking about a Bigger Plan for Your metal Detector.
A "DATA LOGGER".
It's all about software and I'm good in this One.

But the problem is that information in above post about hardware was not enough for me to quite understanding the hardware and how this metal detector is working...
And it's so important to know about hardware for me if I wanted to start analyzing the software of micro.
There was a lot of German Words and some lines that I couldn't understand them…
Anyway,
I know as you said you have a problem with your English,
So can you explain the hardware, parts and the way Minipulse Working in another way or another Language? Russian, French, Persian, Italian?
I have friends in that countries and they can translate your Text quietly for me if you knew one of that languages?
However, hopefully if you did, do not send your information in forum in that languages. It's against the policy. I'll translate and will put the English version in here. Just send the information in my Box or mail.
[email protected]

Life is too short! Hurry my friend. Let's make it

[Broken Diamond]

Block diagram and Functions

Hi again sisco
SorryI forgot to say, please don't forget to send me the block diagram of your miner also .
and can you explain about functions
freq
coil pulse wide
delay
samp pulse wide
inter delay
ground pulse wide
off pulse

in a few lines ?

[Unregistered]

How critical are the diodes 1.5ke400ca and P6KE6.8CA???

Replacement are which one??

help...

[aban]

Hello friends:

I need the source file of the AUTO HEX at C or ASM of minpuls3 to make some changes,if you have it ,please put it in the forum.

Best regrads