Constant voltage on latching relay?

[Foulkesey]

Hi guys,
Hope you can help me. Forgive me, i am an electrician i can follow diagrams but i have trouble designing anything ELV. I will start with what i have and want, then what i think i need but wether it will work i have no idea!

I am trying to have my wing mirrors fold automatically and have bought a plug and play module for this.

I have an existing 3 postion switch, fold, auto and unfold however the module i have got does not leave the mirrors in the outward position as the module uses the central locking trigger to always fold the mirrors. The switch does not have voltage once ignition is off hence the latching relay.

My plan is to install a dual coil latching relay. S1 to be activated by 12 volts from unfold position and s2 to be activated by 12 v from auto position. The trigger cable would then be in NC contacts. So when the switch is in unfold position the trigger is interrupted.

My initial thought was to use a timer delay but if i hit the switch by accident i cannot reset untill the timer has run its course.

My question with this is that the switch has voltage at all times when the ignition is on. But i need the latching relay to continue its operation once the ignition is off. Will a latching relay handle constant voltage 98% of its life?

I'd be greatful for your help and any other ideas you have.
Cheers guys
Joe

 

[riccardo]

Do you have a part number for the relay?
Typically it would be OK to supply power to the switching coil continuously as with most relays they are designed to allow that.

 

[Foulkesey]

Do you have a part number for the relay?
Typically it would be OK to supply power to the switching coil continuously as with most relays they are designed to allow that.[/QUOTE ]

Something like this

 

[riccardo]

Yes you can energise the coils on these all day long. It will only draw around 50mA to 70mA when applying 12V to the coil

 

[Foulkesey]

Yes you can energise the coils on these all day long. It will only draw around 50mA to 70mA when applying 12V to the coil

Thanks riccardo!! Saves alot of hassle ive been looking at 555's otherwise. Thanks for your help!

 

[Reloadron]

You may want to look at the data for your specific relay. While some will not be bothered by constant power, there are others that will. A coil which is not designed for continuous current but rather only pulsed momentary current can run hotter and burn up under continuous current. Additionally the magnetic body can have demagnetization occur in some situations. I am not saying any of this will happen to your specific relay but I would completely check the data sheet for your specific relay and maybe contact the manufacturer just to be sure.

Ron

 

[Foulkesey]

Cheers guys, am i better off using a 555 to create a pulse on power up?

 

[Reloadron]

Depends on the relay as mentioned. Find the data sheet for your specific relay and read it and see what it says about continous power to the coils.

Ron

 

[Foulkesey]

Depends on the relay as mentioned. Find the data sheet for your specific relay and read it and see what it says about continous power to the coils.

Ron

Didnt say anything specific all but that the temperature of the coil will increase 10•c if energised constantly, making the coil 23•c alltogether when energised which would have an effect of what the relay pulls. 23•c seems quite hot in an enclosed space? Cheers

 

[MikeMl]

10C rise is nothing. I would worry if it said 80+deg rise...

 

[Reloadron]

Didnt say anything specific all but that the temperature of the coil will increase 10•c if energised constantly, making the coil 23•c alltogether when energised which would have an effect of what the relay pulls. 23•c seems quite hot in an enclosed space? Cheers

Then go for it! There is not enough rise there to worry about.

Ron

 

[Foulkesey]

Ok cheers guys il pop a post in wen ive got it goin cheers for your help guys