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procos
Joined: 15 Dec 2004 Posts: 12
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electronic adapter |
Posted: Tue Dec 21, 2004 2:54 am |
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input signal : sinus form or rightangled form
grade : min.2mVref; max 6Vref
frequance : f= K*Q ------ 0-10Hz, 0-1100Hz
K- CALIBRATION FACIENT OF FLOW TRADUCTOR
Q - FLOW
ouput signal : 4-20 mAcc ; 0-10Vcc
undertaking resistence : 0-800 ohm for 4-20mA ; >2000ohm for 0-10V
alimentation : wathever( 220 V , 110V, 24 V, 5V)
any idee is very good.
thanx all.
thanx for any answare.
bye
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procos
Joined: 15 Dec 2004 Posts: 12
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? |
Posted: Tue Dec 21, 2004 3:00 am |
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is feasible with PIC16F873 ( TIMER 1 - 16 BITI)
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ckielstra
Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands
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Posted: Tue Dec 21, 2004 5:40 am |
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What is your question????
You give a lot of specifications, but it doesn't make any sense to me. what do you want to do?
Your input signal is both changing in the 0-1100Hz frequency range and the 2mV to 6V range at the same time???
Your output is a standard 20mA current loop, but what resolution do you want to achieve (how many bits)?
Please provide more information. |
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procos
Joined: 15 Dec 2004 Posts: 12
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my |
Posted: Tue Dec 21, 2004 7:07 am |
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sorry
grade : 2mV actual value to 6V actual value
10,12, 16 biti
palet turbine intersect magnetic field create of permanent magnet and create one electropower in bobbin.
frequance of this tension = rotation speed of turbine x number of palet
rotation speed of turbine is proportional with flow range |
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SherpaDoug
Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA
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Posted: Tue Dec 21, 2004 8:45 am |
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For the input you need a comparator (LT1011 comes to mind) to take a signal as low as 2mV and make in into a logic signal to drive the PIC. Give it a little hysteresis so it won't oscillate or pick up noise. The datasheet of the LT1011 describes this.
You can use any PIC with PWM to generate a DC output. You will need some amplifiers to get 0 to 10V and to get the 4 to 20mA from the PWM voltage.
Any PIC can do the math. The 220VAC to 5V DC power supply is another whole can of worms! I would design the circuit for 5VDC, and use adapters to turn the other voltages into 5VDC. _________________ The search for better is endless. Instead simply find very good and get the job done. |
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procos
Joined: 15 Dec 2004 Posts: 12
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thanx very much |
Posted: Wed Dec 22, 2004 1:08 am |
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thank you SherpaDoug and ckielstra
i can show some schematic .
The pic with PWM who can use is: 18f242-i/sp.
is a flash and i can programate more times.
and stiil a littel:
with this signal i want define 3 parameters
1) time of fuction
2) total flow
3) instantaneous flow
i can ?
i need and date end time real (dalas ds1287 or motorolla mccs146818)
can i help my with one schematic?
i am newbie.
thanx very very very much
best regardes
constantin |
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procos
Joined: 15 Dec 2004 Posts: 12
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yes |
Posted: Wed Dec 22, 2004 4:49 am |
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yes.true
3 butons
yes |
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SherpaDoug
Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA
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Posted: Wed Dec 22, 2004 8:30 am |
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Read through the datasheets for the chips you intend to use. Then if you post a .pdf or .jpg of your schematic we can comment on it. Note support may be rather sketchy for the next 2 weeks with the holidays.
I also recommend you get a flowmeter on your desk you can spin with your finger or breath and if possible an oscilloscope so you can see how the signals look. _________________ The search for better is endless. Instead simply find very good and get the job done. |
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