AVR-Chat

> -----Original Message-----
> From: JoeT [mailto:joet@attg.net] 
> Sent: Wednesday, 11 February 2004 1:14 AM
> To: AVR-Chat@yahoogroups.com
> Subject: RE: [AVR-Chat] Relay Control
> 
> 
> I was going to go for the PCB shielding next. It does not 
> have a ground plane. I used a 10k a pull up resistor on int0, 
> I'll try 1k. What is a "a snubber network on the contactor" ?
> 
> Thanx
> JoeT

The opto isolator *should* provide the isolation from spikes, so the 10K
is probably fine. I would suggest the problem is the EMI from the
Contactors getting into the processor and triggering the Int0.

A snubber network is a cap and resistor placed across the contacts of
the contactor (and also the drive relay) the function is to quench the
arc drawn as the contacts open, this is achieved by the resistor and
capacitor providing a path for the current to flow as the contacts open,
the leakage current is not high, so the device being driven does not
operate.

Any good electrical shop (industrial) should be able to sell you a
snubber network in a signal package with two leads hanging out. IT will
need to be selected to suit the load, but they may be able to help you.

Remember young Jedi ;o) google is your friend.

Regards,

Kat.

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