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Topic: how to reduce the electrical noise (Read 2005 times) previous topic - next topic

paimpozhil

Hi All

My arduino standalone board that i soldered with voltage regulator for staircase lights automation seems to be restarting/flickering whenever i switch on my tubelight which flickers almost every time due to start issue or whatever.

Is there anyway to immunize the arduino from power glitches like this? like bigger caps for voltage regulation,etc?

Someone suggested keeping a lower value resistor for reset instead of 10k, how lower that should go?

Running the arduino from the batteries will fix?  or may introduce more problems than the fix?

retrolefty

Well without a complete wiring diagram including power source it's hard to give you specific advice, but yes proper filtering and bypass caps of appropriate size and applied correctly can generally deal with your problem, which sounds more like voltage sage due to load switching rather then just random circuit noise.

Lefty

paimpozhil

Ok I basically use the same version here

http://arduino.cc/en/Main/Standalone
2 10uF capacitors.
Without the PUSH button to reset and the in-circuit programming chips
with exactly same parts and wirings.. I have soldered them all in the solder board. I will take a photo very soon


Power source is my grid and wallwart 12V , I have used voltage regulation in the circuit using the 7805 .

paimpozhil

What is the next size of caps I can try instead of the 10uF?

Grumpy_Mike

Quote
Someone suggested keeping a lower value resistor for reset instead of 10k, how lower that should go?

Ignore him he knows not what he says.

Quote
2 10uF capacitors.

put 2 ceramic capacitors of 0.1uF in parallel with the ones you have. Mind you the capacitors shown on the link do not look like 10uF at all they look like 10nF.

Quote
I will take a photo very soon

Good.

Quote
I have used voltage regulation in the circuit using the 7805

Have you got capacitors on the input and output pins?

mixania

I think a pull-up resistor between a pin and VCC would help.
Arduino Uno R3
Mac OSX Lion

paimpozhil

Hey ,

Thank you for replying .

I will try the 0.1uF caps in parallel, but I have to buy them tomorrow to try.

I have capacitors on both sides of the 7805.



Quote
Someone suggested keeping a lower value resistor for reset instead of 10k, how lower that should go?

Ignore him he knows not what he says.

Quote
2 10uF capacitors.

put 2 ceramic capacitors of 0.1uF in parallel with the ones you have. Mind you the capacitors shown on the link do not look like 10uF at all they look like 10nF.

Quote
I will take a photo very soon

Good.

Quote
I have used voltage regulation in the circuit using the 7805

Have you got capacitors on the input and output pins?

paimpozhil


I think a pull-up resistor between a pin and VCC would help.



Which pin and VCC ? sorry im very new to arduino land.

mixania



I think a pull-up resistor between a pin and VCC would help.



Which pin and VCC ? sorry im very new to arduino land.


For example: If you are using a wire (you would actually be using at least two in this case) to communicate with another Arduino. And you would want to reduce the noise, consider connecting a part of the wire to the vcc through a pull-up resistor. Connect the end of the wire to the final destination.
Arduino Uno R3
Mac OSX Lion

SirNickity

I don't usually build a circuit with PSU rail caps less than 100uF.  Often, 470uF.

paimpozhil


I don't usually build a circuit with PSU rail caps less than 100uF.  Often, 470uF.


Now If i replace my 2 10uF with lets say 470uF, u think that would improve/help this ?

MarkT


Hi All

My arduino standalone board that i soldered with voltage regulator for staircase lights automation seems to be restarting/flickering whenever i switch on my tubelight which flickers almost every time due to start issue or whatever.

Is there anyway to immunize the arduino from power glitches like this? like bigger caps for voltage regulation,etc?

Someone suggested keeping a lower value resistor for reset instead of 10k, how lower that should go?

Running the arduino from the batteries will fix?  or may introduce more problems than the fix?


I think this thread has drifted off track rather - as I understand this there is a fluorescent light fitting that's creating
mains transients that are reseting the Arduino by some mechanism.

Likely things are:

1) inadequately protected power supply passing on the transient to the 5V rail
2) interference being picked up by cables between the Arduino and the staircase lights.

But I've a few questions:  What are these staircase lights?  Are they distinct from the fluorescent light
that is causing the problems?  How are the staircase lights controlled by the Arduino?  Are relevant
logic-level signal cables shielded and routed away from mains wiring?
[ I won't respond to messages, use the forum please ]

paimpozhil

Hi  MarkT,

Staircases are CFL lights  and yeah they are totally independent of the florescent

There are 6 of them and I have wired all of them to relay board which has 8 relays and an ULN2003.

I have ensured the digital wires and AC mains wire are separated out by few inches.



Grumpy_Mike

That dosn't matter. It is electromagnetic induction that couples the interference.

MarkT


Hi  MarkT,

Staircases are CFL lights  and yeah they are totally independent of the florescent

There are 6 of them and I have wired all of them to relay board which has 8 relays and an ULN2003.

I have ensured the digital wires and AC mains wire are separated out by few inches.





A few inches isn't great - route them completely away from each other.  sheided cable is good,
ferrite toroids can be good to reject common-mode transients.  You may also have a ground loop
which you need to think about - bring the mains to the relay board and Arduino PSU in one place
to avoid such a loop.
[ I won't respond to messages, use the forum please ]

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