• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Latching relay question.

Status
Not open for further replies.

alphacat

New Member
I have learned how a relay works, but doesnt quite understand how latching relay works.
In non-latching relay, the magnetic field creates a magetic force which keeps the armature (the COM pin) attached to the NO pin of the relay, correct?

In the case of lacthing relay, what keeps the armature attached to the NO pin, once the coil has been de-energized?

Thank you.

P.S.
I'm sorry for my behavior in the last thread.
I'll conduct myself in a proper manner.
 

ericgibbs

Well-Known Member
Most Helpful Member
I have learned how a relay works, but doesnt quite understand how latching relay works.
In non-latching relay, the magnetic field creates a magetic force which keeps the armature (the COM pin) attached to the NO pin of the relay, correct?

In the case of lacthing relay, what keeps the armature attached to the NO pin, once the coil has been de-energized?

Thank you.

P.S.
I'm sorry for my behavior in the last thread.
I'll conduct myself in a proper manner.
hi,:)
If you are interested in relay types, look here:
General-purpose Relays | Technical Guide | Singapore | Omron IA
 

Hero999

Banned
Hi omegamouse :D

It depends on the type of latching relay.

Some have two coils: one to turn the relay on and another to turn it off.

Some have one coil: connect the power to it in one direction, it turns on, reverse the power connections and it turns off.

Imagine you have a toggle switch with a steal lever and two large electromagnets placed either side of it: activate one and it turns on, activate the other and it turns off. This is a two coil latching relay.

Imagine you have a toggle switch with a permanent magnet fixed to its lever and a large electromagnet placed next to it: connect the power in one direction and the magnet will be drawn towards it, turning the switch on, connect the power in the other direction and it will be repelled causing it to turn off. This is how a single coil latching relay works and is similar to how the voice coil in a speaker moves back and forth.

A latching relay has a similar mechanism to both of the above but it's neatly integrated into an enclosure.
 

Externet

Active Member
Your ball pen has a mechanism that engages its tip on one push and disengages the next.
That same mechanism attached to a single coil solenoid would make a latching relay. One push connects, the next disconnects.
Replacing your finger with an electromagnet as in a relay, does the latching feature.
Miguel
 

alphacat

New Member
Thanks bro.

So the difference between non-latching relay and latching relay is that the latching relay has a permament magnet on its COM, while the non-latching relay doesnt have it?
 

k7elp60

Active Member
Thanks bro.

So the difference between non-latching relay and latching relay is that the latching relay has a permament magnet on its COM, while the non-latching relay doesnt have it?
No! Some latching relays have a mechanical latch like the aformentioned pens, while some use a permanent magnet for latching, and others use a second coil to unlatch the mechanical latch.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top