Question: I'm currently learning electronics and right now, I'm trying to use a relays... without success. Here is a picture of my circuit:

[![enter image description here](https://i.stack.imgur.com/VLzbL.jpg)](https://i.stack.imgur.com/VLzbL.jpg)

First of all, don't mind the 2 cables on the top right and the relay on the bottom right, they are not used.

So, from what I understood about relays, here are my thoughts about this circuit.

When the button is not pressed, the relay does not receive any tension, so the pins connected to the lightning LED are active, which is why the LED on the top is lightning... That I get...

Now, when I press the button, a 12V DC tension is going inside the relay, so I was kind of hoping that it would make it switch and then the second LED would be lightning but... no...

The relay is an AXICOM IM26, you can find the datasheet of this one in here: <http://www.te.com/commerce/DocumentDelivery/DDEController?Action=showdoc&DocId=Specification+Or+Standard%7F108-98001%7FV%7Fpdf%7FEnglish%7FENG_SS_108-98001_V_IM_0614_v1.pdf%7F4-1462039-1>

However, a friend made me notice that this datasheet "talks about" a switching current of 2/5A but I have trouble to imagine that this small relay really requires that amount of current to switch, especially because it is writing "12 V DC" on it, which, for me, tend to indicate that it switches at 12V. But it would explain why it is not switching when I press the button.

Can someone explain me what is wrong with my circuit ?

Thanks

Answer: 
Your relay has an 'ultra high sensitive coil' which suggests it is biased with a permanent magnet. If this is the case then you must apply voltage to the coil with the correct polarity, otherwise the coil will cancel out the bias magnet's force instead of adding to it, and the relay won't operate. 

If the white stripe on your power supply cable is positive then it appears you have the polarity reversed (positive should go to pin 1 of the relay, and negative to pin 8).

> 
> this datasheet "talks about" a switching current of 2/5A but I have
>  trouble to imagine that this small relay really requires that amount
>  of current to switch
> 
> 
> 

That is the rating of the contacts, ie. how much current it can *switch*. The coil requires 10.2V DC and has a resistance of 2880Ω, so it needs at least 10.2/2880 = 3.5mA to operate. At 12V the coil should draw 12/2880 = 4.2mA.
AM26 is rated for 12V at 50mW 

It comes in 3 ranges of sensitivity, this being most sensitive.
If coil Power = 50mW @ 12V then current is 50mW/12 ~ 4mA 

This is pretty easy to drive and you might be able to make it click with the 9V battery across the coil with + on pin 1. Although due to hystereis, the guaranteed or MUST SWITCH threshold is 10.20V and the MUST release threshold is 1.20V but it MAY switch in between.

FYI
The lowest contact rating is 2A resistive. So this relay has a net switch gain at max load of 2A/4mA = 500 or you could say a a coil sensitivity of 0.2% or rated current for a 12V coil.