hi everyone,,
i want to ask for a guidance for my project . The project basically use Temperature sensor (LM35) as input , PIC as "analyze" item and ac motor (output-speed change)..
here the problem is regarding 2 things
1. ADC problem-- LM35 interface pic
-either use PWM or sampling
2.the big one- how to interface PIC 16f877 and ac motor--can provide some code or diagramm..just for the guidance..
to be truth... i quite new in this area (microcontroller)....someone please...
wait for ur respond....
temperature sensor (LM35) + PIC16f877 + ac motor
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- Posts: 120
- Joined: 11 May 2008 18:47
Re: temperature sensor (LM35) + PIC16f877 + ac motor
Hi,
I don't know whether helps or not but...
There is a sample code for PIC and LM35 in the book called "ADVANCED PIC MICROCONTROLLER PROJECTS IN C".
I think that would be a good start.
Be successful.
I don't know whether helps or not but...
There is a sample code for PIC and LM35 in the book called "ADVANCED PIC MICROCONTROLLER PROJECTS IN C".
I think that would be a good start.
Be successful.
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- Posts: 4
- Joined: 13 Feb 2010 05:47
Re: temperature sensor (LM35) + PIC16f877 + ac motor
thanks for the info..really hope it function well for the project...
by the way, how about the interface with ac induction motor.. isn't been conclude in the book??
i hope for Ur opinion about that...
waiting for respond....
by the way, how about the interface with ac induction motor.. isn't been conclude in the book??
i hope for Ur opinion about that...
waiting for respond....
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- Posts: 120
- Joined: 11 May 2008 18:47
Re: temperature sensor (LM35) + PIC16f877 + ac motor
Hi,
No,not about motor,just for LM35 but the good point is the program is for Mikroc.
Be successful.
No,not about motor,just for LM35 but the good point is the program is for Mikroc.
Be successful.
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- Posts: 4
- Joined: 13 Feb 2010 05:47
Re: temperature sensor (LM35) + PIC16f877 + ac motor
i am really blur and confused right know...can anyone tell me on how to interface the PIC16f877 with ac induction motor ( speed)...--ceiling fan...
guide me please....
urgent...
guide me please....
urgent...
Re: temperature sensor (LM35) + PIC16f877 + ac motor
I don't know for sure, but I think one way to control the speed of the motor is to use the PIC as a frequency converter. That means you have to recreate the sinusoidal voltage at different frequencies. As for this I do not have any code nor I have any idea where you could find something to help you.
Is the ac motor a 3 phase motor? If by construction it gives you access at the rotor's coils you can change the speed by adding resistors like in this link: http://em.ucv.ro/elee/ro/realisations/m ... igure6.jpg
If it is not a 3 phase motor (you say it is a fan motor) than i guess the first part is the way to go.
Is the ac motor a 3 phase motor? If by construction it gives you access at the rotor's coils you can change the speed by adding resistors like in this link: http://em.ucv.ro/elee/ro/realisations/m ... igure6.jpg
If it is not a 3 phase motor (you say it is a fan motor) than i guess the first part is the way to go.
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- Posts: 4
- Joined: 13 Feb 2010 05:47
Re: temperature sensor (LM35) + PIC16f877 + ac motor
thanks for the reply
eventually, this project used the ceiling fan motor-single phase motor...
can u suggest something...?
totally need help...
eventually, this project used the ceiling fan motor-single phase motor...
can u suggest something...?
totally need help...
Re: temperature sensor (LM35) + PIC16f877 + ac motor
I've done a little reading and I have an idea. These motors can be controlled through variable voltage and fixed frequency or fixed voltage variable frequency.
I think it is easier to variate the voltage. You can use the PIC as a chopper. I believe the technique is called PWM-Pulse With Modulation. Of course you will need other components in order to support the motor's current and voltage. I haven't tried this yet so I don't really now how it works or if it works, but in theory does . The idea is to give pulses to a switch (relay transistor or anything that can act like a switch) in order to control an analog device (your motor in this case). the pulse is given by setting a pin to 1 and 0 at a chosen time rate. if you want these pulses to be faster you simply choose a shorter time rate.
create a few procedures and test them until you get the pulsing time you want.
For how to connect this to the motor I think there are a lot of methods on the internet.
Here: http://www.freescale.com/files/microcon ... AN3471.pdf is a solution using PWM for a ceiling fan.
Hope it helps.
I think it is easier to variate the voltage. You can use the PIC as a chopper. I believe the technique is called PWM-Pulse With Modulation. Of course you will need other components in order to support the motor's current and voltage. I haven't tried this yet so I don't really now how it works or if it works, but in theory does . The idea is to give pulses to a switch (relay transistor or anything that can act like a switch) in order to control an analog device (your motor in this case). the pulse is given by setting a pin to 1 and 0 at a chosen time rate. if you want these pulses to be faster you simply choose a shorter time rate.
create a few procedures and test them until you get the pulsing time you want.
For how to connect this to the motor I think there are a lot of methods on the internet.
Here: http://www.freescale.com/files/microcon ... AN3471.pdf is a solution using PWM for a ceiling fan.
Hope it helps.
Re: temperature sensor (LM35) + PIC16f877 + ac motor
The LM35 could give more output power or voltage in your ceiling fan motor. Anyway, it should be better that the thermocouples.
Re: temperature sensor (LM35) + PIC16f877 + ac motor
Our neighbor are doing electric fan repair. I heard that they also use LM35. As they said, LM35 gives more output voltage. It is the same with jennyfan.