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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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