My questions about this particular DPDT 5V relay:

a) Specs for AC and DC do not look very consistent. Why?

b) What if I use it to switch a load on 30V DC with 850 mA (maximum)?

c) I come from reading Wikipedia but I am not sure about this:

NC (normally closed) is the contact that stays closed when the coils is NOT energized?
NO (normall open) is the contact that stays open when the coil is NOT energized?

Thanks for any help and the time you spent here.

 

Hello,

When you take a look in the datasheet this graph will show up:

I have also attached the full datasheet.

There are three contacts in a throw over switch
CO or COM or COMMON , in the drawing shown as C1 and C2 for the DPDT setup.
NC or Normal Closed, in the drawing shown as B1 and B2 for the DPDT setup.
NO or Normal Open, in the drawing shown as A1 and A1 for the DPDT setup.
This is the situation when the relays is NOT energized.
When the relays is energized, the contacts between C1 and B1 will be opened and C1 and A1 will be closed.
When the relays is energized, the contacts between C2 and B2 will be opened and C2 and A2 will be closed.

Bertus

 

My questions about this particular DPDT 5V relay:

a) Specs for AC and DC do not look very consistent. Why?
If a circuit carrying a substantial current is broken,an arc is created.
The arc is influenced by both the operating voltage, the current, the speed of operation & final gap of the relay contact.

AC waveforms return to zero once per cycle,so they are inherently capable of suppressing an arc.
Because of this,higher voltages can be used with AC.

As DC waveforms do not return to zero,they cannot suppress the arc,so the operating voltage rating needs to be reduced for a given current.

b) What if I use it to switch a load on 30V DC with 850 mA (maximum)?
From Bertus'graph,yes.
c) I come from reading Wikipedia but I am not sure about this:

NC (normally closed) is the contact that stays closed when the coils is NOT energized?Yes
NO (normall open) is the contact that stays open when the coil is NOT energized?Yes

Thanks for any help and the time you spent here.

I hope this helps.

 

Hola Bertus and vk,

Gracias. Clear enough!