Hello friends this is a newbie question. I am trying to use this industrial type push start switch in an arduino prototype but I can't get it to work.
It is not about code that I write because when I use classic arduino press button it works. I think it is an electrical issue.
Thanks for your valuable replies in advance.
It' a NC (normally closed) button, so maybe don't behave as you expect, but the opposite.
Ciao, Ale.
Under the part number, there's that little pictograph, with NC in parenthesis after it - the switch is normally closed, not normally open. Meaning, the two sides of the switch are connected to eachother when you're not pressing the button, instead of when you are pressing the button. Is this it?
Connect terminal 1 to GND and terminal 2 to your input pin, in setup(), set pinMode to INPUT_PULLUP, the pin will be HIGH when button is pressed.
Oh well, another old line company (Telemechanique), gone to chinkdom. >:(
It's not a "push start" button, but a push STOP button. It breaks a circuit, causing power through the start button to drop out.
The switch isn't designed for switching low level signals. I recommend providing more whetting current to help avoid contact oxidation. Try using any resistor from 1K to 2.2K to provide at least 2mA through the contacts.
Several ways to connect:
@dlloyd:
Good point.
@dlloyd can you explain a little bit more. And I know this is a stop button but I am trying it with a green start button. I just took a photo of the red one to show the type of button I use.
Any switch would have a minimum load it could reliably control. Unfortunately, this isn't usually specified. The material used for the contacts plays a role as to the range in current and voltage it can switch.
Your 6A/400V switch wouldn't have gold flashed contacts or similar to reliably switch low current at low voltage levels. For example, if you're only switching 50µA, the contacts could easily oxidize and fail and also be affected by humidity and fail. So to get higher reliability, need to switch more current.
I remember now, the "Square D digest" spec'd 10mA minimum for their low current duty "ice cube" relays.
I used to have a book with all the details. Seems a bit more difficult finding this stuff on the internet (they don't want to hurt product sales I guess), but I did find a few things:
From here (page 19): Contact Block Performance/Selection
"If the load to be switched is of a very low energy level, any contaminants or non-conducting films on the contacts may prevent a circuit from being established when the contacts are operated. If loads below 48V DC and 0.1 A, or below 24V AC and 0.4 A, are to be switched, the user must be cautious when selecting the contact materials."
There's a fantastic table here on page 4 providing details of various contact materials.
