Low voltage protection

[kenkelso]

I have fitted a REUK low voltage protection circuit to my leasure battery setup, this triggers a 30A relay. Obviously the relay takes some power to hold it closed which will help to deplete the leasure batteries. I know it is possible to reduce the voltage required to maintain the relay in the closed position using a capacitor and resistor (REUK mentions this on it's site)
Has anyone used this technique and does it work OK ?

Ken

[Oldiebut goodie]

Just use a latching relay, it then takes no power.
Theses are mine - 100A and 120A:

[keytouch]

How does the latching relay work? If it uses no power, how does it disconnect when the power to it is turned off by the LVD?

[Oldiebut goodie]

I don't believe that the question has been put! The module excites the relay which latches the relay off disconnecting the power. There is still the battery voltage sense connected of course.
The power through it is disconnected by the voltage sensing circuits in the electronic module. On mine I have just connected push buttons to reset them although some will automatically reset when the voltage rises again. Not cheap devices though. The low voltage is sensed at the battery side of the relay which then causes the module to send the signal to the relay to latch it off.
If you look at the relay on the left you can see a green wire which is the sense. The blue and black are the switching power to the relay, I can't remember what the transistor was for offhand - I knew at the time of fitting it! The 2 yellows go to the reset button.

[kenkelso]

Thanks Oldie, I had thought of a latching relay but didn't want to go to the expense of one.

Ken