Battery life of a relay actuator
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Anyone has the relay node running off batteries? I have one that switch external lights on at sunset and off at sunrise but it is located in an awkward place and I am not sure I want to start re-wiring to get 220->5v plug in the box as well. Using Nano.
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Unless you use a very big battery, it's not going to work. I did some testing with a battery powered relay node (2 AA) and it lasted ~18hrs with 4 activations of the relay.
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Would this work with solid state relays? They should draw much less current.
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SSR uses less power but is not as efficient on the load side
If the relays are switching AC, you have the power there and I would recommend using it. I have used a charger like http://www.ebay.com/itm/321096550392?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT -> open case and use only the electronics.
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@FotoFieber hmmmm will do that. don't really like to get the 220v into the box but i guess thats life. would have been nice if the relays would work like the more advanced irrigation solenoids and "latch" in position so they take 0ma all the time other than a very short peak for flipping the relay and latching it in position.
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Latching relays do exist.
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@Jan-Gatzke yes, they do exist! silly of me to muse instead of googling. i see that they are all high voltage (12v-30v). is that why no one is using them? they seem to be perfect for relays that operate only once or twice a day. can Batteries produce such high voltage? I am sorry for the silly questions - I have very little understanding of electrical components
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Looks like Google and you are still not best friends.
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@Jan-Gatzke indeed. Sorry about that. I actually looked on aliexpress and things were either very very expensive or high voltage. will give this one a try... I guess I will need some kind of capacitor to allow it to have enough juice for the flip and latch. if it works it can be great, as I guess I am not the only one who tried to get as little 220v into the box. these little transformers also create a bit of heat.
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@Moshe-Livne You'll want to add a diode such as the 1N4001 in parallel with the relay coil to prevent damage to the Arduino when the relay is turned off, and a transistor between the Arduino pin and the relay to switch the power to the relay as the Arduino typically can't supply enough current for the relay coil.
Cheers
AlEDIT: Here's an example of a circuit: http://www.ecs.umass.edu/ece/m5/images/relay_circuit_schematic_L.jpg
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@Sparkman ended up ordering http://www.aliexpress.com/item/Passive-Bistable-Latching-DPDT-8-Amp-Power-Relay-Module-5V-Version-RT424F05/2003476647.html as form factor is not really an issue where these relays will be but convenience is. I think it includes the diodes but not the transistor. Thanks!!!!
