Re: Novel switch solution?
Posted: Fri Dec 18, 2015 1:55 pm
Hi Rob
It depends on what your switching (power/amps) to determine relay size.
A six volt relay in my experience will normally work between 4v and 8v dc and then you just have to look at what power your switching .
I think a 6v mini relay will handle 10amp dc and a standard 6v relay will go up to about 20amp dc, this is only a guide from my experiences over the years. Most relays will have their switching loads marked on them.
A 12v relay generally operates from 8v dc to 15v dc but will be bigger physically, but will also handle larger loads.
The beauty of using this circuit is that if you forget to switch off your tank once the battery voltage drops below 4v (6v relay) the voltage is not strong enough to hold the relay coil on and so the relay drops out and hence kills the power.
Thus your battery is never going to get totally di- charged and maybe damaged. When I did rc power boats I always used this circuit to prevent my batteries getting damaged.
denzil
It depends on what your switching (power/amps) to determine relay size.
A six volt relay in my experience will normally work between 4v and 8v dc and then you just have to look at what power your switching .
I think a 6v mini relay will handle 10amp dc and a standard 6v relay will go up to about 20amp dc, this is only a guide from my experiences over the years. Most relays will have their switching loads marked on them.
A 12v relay generally operates from 8v dc to 15v dc but will be bigger physically, but will also handle larger loads.
The beauty of using this circuit is that if you forget to switch off your tank once the battery voltage drops below 4v (6v relay) the voltage is not strong enough to hold the relay coil on and so the relay drops out and hence kills the power.
Thus your battery is never going to get totally di- charged and maybe damaged. When I did rc power boats I always used this circuit to prevent my batteries getting damaged.
denzil
. Don't forget this circuit can be to operate something as well as just switch power. ie a reed switch at the end of the travel of a piston would act as limit switch. or a servo with a magntic on it could operate numerous reed's to switch on and off accessories ( a magnet can be a lot smaller than micro switches. the possibilities is up to the imagination of the modellor 
.