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industrial applicaion for pic

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scorpionss22

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hi all i need power supply for pic
i found problem with pic in industrial application
so i want working power supply with industrial application
for pic



thanks
 

you use a switching power supply
 

use a switching power supply
Design PCB reduce EMF
ground vcc line larg for use current
 

Hello

You better go to Atmel AVRs family, as they don't suffer from this problem at all.

Instead of wasting time for designing a switching power supply for PIC, the Atmel AVR will be happy with the conventional small transformer, bridge rectifier, smoothing capacitor, and 7805 regulator. For sure, I can guarantee you that it will work with non of problems mentioned above.


Kind day
 

thanks i know switching power supply is the solution

but i need practical schematics

thanks
 

Hello

Is the only possible solution is switching power supplies, what about LM317, does it solve this problem.

Regards
 

metal said:
Hello

Is the only possible solution is switching power supplies, what about LM317, does it solve this problem.

Regards
Click to expand...

i dont quite understand your question. the LM317 can be used as a linear regulator as well as a switching regulator. look in the datasheet for application hints.

and i have told you before that it doesnt depend on which type of power supply you are using but it depends on the quality of the power supply. a quality built linear power supply, be it a LM317 or anything like that, will have no problems for the PIC.
 

Salam

Take it easy samcheetah, no need to get so upset :)

I meant, if I want to use PIC in a car project, is it enough to go with 7805 or LM317, with some capacitors, 1st Solution.

The second, Is it better to use SMPS, or just the 1st solution solves the problems of power supply disturbances.

If the 1st solution really works for a car project without any problems, then I will have lots of mind relief :) Please guys, tell me about your experiences

Thanks
 

first of all i didnt mean to be rude. ill be careful with selection of the words next time.

well, i havent really designed a PIC project for a real type of industrial application in which there are alot of spikes and transients on the power line (like automotive applications as you said). most of my projects work well with the usual fixed and variable voltage regulators with proper capacitors according to the datasheet.

i cant comment on SMPS being a solution to this problem. but if someone who has really experienced that SMPS solves the problem of PIC resetting itself then please share your experience.
 

Hello

Tonight I will try to build a small circuit for the PIC to work in the car, lighting some LEDs in specific time dependent sequence to see whethere the PIC resets or not, just for test purposes, and I will use LM7805 regulator to see if it works, if not I will try to have an SMPS, and see what happens.

Kind day
 

hi all ,

be sure it will work in car , there are many circuits working in a car like alarm syetem and .... , if they wanted to use switching power supply then it's cost wouldn't be good ... !

using 7805 and some caps would solve the problem and if the circuit doesn't work well , it has another problem exept power supply !

regards .
 

what about u all i ask for switching power supply
and u all talking in another things like car
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


thanks for cooperation
 

scorpionss22 said:
what about u all i ask for switching power supply
and u all talking in another things like car
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Click to expand...

first of all i apologize for going off topic.

and secondly i would like you to be specific. you have said that you want see a schematic of a switching power supply. that is like saying that you want to bake a cake :D you should also tell which type of cake, should it be round or square, a chocolate cake or a pineapple cake? etc.

so you should tell us what are your power requirements. but be warned that switching power supply design is a bit harder than linear power supply design. and switching power supplies are noisy and they produce interference with analog circuits.

but anyway go to **broken link removed** there you can find alot of tools that will help you in building your power supply

i hope that helps
 

Hello

Last night I built a circuit consisting of PIC16F84A, 7 segment display, some resistors, LM7805, and some capacitors.I used the ordinary transformer, bridge, and smoothing capacitor. The circuit simply counts from 0 to 9 continuesly.

To make a noisy environment, I have connected three motors on the same mains outlet from which I am feeding the transformer for PIC circuit, also connected some neon lamps.

I started every thing, trying to make disturbance, I also connected some fans on the power supply of the PIC, before the regulator.

The results were amazing, I had no problems at all, the PIC never reset, even when I switch on/off the big motors, or neon lamps, the PIC never reset.

I will try the circuit in the car today, and when I finish, I will draw the schematic, and provide a table with all results I had.

Last thing to say, according to the results I have achieved untill now, I don't think the SMPS is necessary even in a noisy environment such as industrial, well designed linear power supply will do the job, and the I apologise for my previous answer regarding AVRs, as I thought they may be a better solution instead of a PIC in a noisy environment, as I have never tested the PIC in a noisy environment, but I was wrong, the PIC behaved exactly like the AVR, never reset during my experiments.

Kind day
 

Some things to consider for PIC users:

**broken link removed**

**broken link removed**
 

Don't use too big a value on the reset line pull up resistor. This is a common mistake. The maximum value is about 39K as the mclr line has a typical leakage of 5uA. 10K is a good value to use. some people just wak a 100K on it and then wonder why it keeps resetting!
 

Hello


CHEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEER UP guys :)

I have tested the PIC in my father's car today, no single reset problem appeared at all, I have connected the circuit to a lamp, switched it on, and started counting,0, 1, 2,...9, 0, .....9. Then I started the car engine to see what happens, in deed the PIC did not have any problem at all.

btbass I have used many resistors for MCLR, starting form 1K to 470K, while testing in car, also I had no problems at all resistors values, but as you said it must be 10K or lower may be better :)

Kind day guys

The victory day ;)
 

I managed to reduce such noises with switching regulators like LM2574 .
The LM2574 contains all of the active circuitry necessary to construct a stepdown (buck) switching regulator and requires a minimum of external components.
 

ZeleC said:
I managed to reduce such noises with switching regulators like LM2574 .
The LM2574 contains all of the active circuitry necessary to construct a stepdown (buck) switching regulator and requires a minimum of external components.
Click to expand...

Good solution for stepdown (or stepup) switching regulator up to 1.5A is MC34063
www.onsemi.com/pub/Collateral/MC34063A-D.PDF
 

hi metal ,

as you have tried a lot , it's good that now you test your circuit with AVR and 8051 to compare them in the same coditions ,

regards .
 

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