how do i hook up a spdt?

Thread Starter

ShockBoy

Joined Oct 27, 2009
186
my schematic shows nc/no output, along with it's input;;that's three connection points. then i have the two connection points straddled by a diode. That makes 5 connection points. My relay has 7. I remind you all that I am new to electronics. how do i hook this up?

Thanks for the assistance.
 

Paulo540

Joined Nov 23, 2009
191
Does the relay have a remote switch terminal pair? Maybe that's the other two. Or, it might have a second set of contacts which is possible.

Anyways, the two pins 'straddled' by the diode are the coil make sure to observe proper polarity. If there is a symbol on the top or side of the relay, you will see which pin goes where. There will be a common and it will be touching another contact while spaced away from the other in the diagram. The one it is touching will be the NC and the one it is spaced from will be NO.

Its hard for me to describe in pure words but I hope this makes sense.
 

VoodooMojo

Joined Nov 28, 2009
505
my schematic shows nc/no output, along with it's input;;that's three connection points. then i have the two connection points straddled by a diode. That makes 5 connection points. My relay has 7. I remind you all that I am new to electronics. how do i hook this up?

Thanks for the assistance.
SB,
can you post your schematic or perhaps the relay part # ?
 

Thread Starter

ShockBoy

Joined Oct 27, 2009
186
Does the relay have a remote switch terminal pair? Maybe that's the other two. Or, it might have a second set of contacts which is possible.
Ya, the two small 'mounting looking posts'. I am confused. look at my pic post of what i've got.
 

SgtWookie

Joined Jul 17, 2007
22,230
Here, I drew the coil and contacts into what it should look like:



Try using a meter set to measure Ohms between the two coil pins, and then between the two COM pins and the NC pin. You should read nearly 0 Ohms between the two COM pins (connected by red) and the NC pin. You might measure a couple hundred Ohms between the coil pins.
 

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SgtWookie

Joined Jul 17, 2007
22,230
As long as you have at least one of the COM terminals/pins connected, you're fine.

There are a couple of COM pins to give board designers flexibility in where they can connect the COM signal. The basic layout is similar to an industry standard relay design.
 
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