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Does the coil on a 12v spst relay consume power from my battery when active?

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Jeffrey Screen

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Does the coil on a 12v spst relay consume power? If so how much each hour? I assume it would, I just don’t know how much. Also how much does the coil consume on a 12v dpdt relay?
Thanks

Spst :

• Initial contact resistance (at 6VDC 1A): 50mΩ Max.
• Operate time (at nominal volt.): 10 msec. Max.
• Release time (at nominal volt.): 5 msec Max.
• Initial insulation resistance: 100MΩ Min. (DC500V)
• Initial dielectric strength:
- Between open contacts: AC500V, 50/60 Hz 1Min.
- Between coil and contact: AC500V, 50/60 Hz 1Min.
• Vibration resistance:
- Functional: 10 ~ 55Hz at double amplitude of 1.5 mm
- Destructive: 10 ~ 55Hz at double amplitude of 1.5 mm
• Shock resistance:
- Functional: 20G Min.
- Destructive: 100G Min.
• Endurance (operations):
- Mechanical (at 7,200 ops./h): 10,000,000
- Electrical (at 600 ops./h): 100,000
• Ambient Temperature: -40°C ~ +125°C (no condensation)

Dpdt:
  • Product Name : Relay with Socket;Relay Model No. : JQX-13F;Socket Model No. : PTF08A
  • Coil Voltage : DC 12V;Contact Capacity : 10A, 240VAC;10A, 28VDC : 10A, 28VDC
 
Last edited:

Nigel Goodwin

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Obviously it does, the actual amount depends on the specific relay (which you haven't mentioned) - the details are usually printed on the relay, the voltage and the coil resistance, simple ohms law gives you the current.
 

Jeffrey Screen

New Member
I updated my thread with more information. I am building an auto magic chicken coop door. I want to minimize the energy use to save on my battery.
 

dknguyen

Well-Known Member
Most Helpful Member
Use a relay that latches both ways then. Only requires a pulse of power to the coils to change states (though power is still consumed by the main thing which usually dwarfs the coils power).

what is the relay powering and what is it being controlled from?
 

alec_t

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Search the site for threads about chicken coop doors. It's a popular topic.
 

Reloadron

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This is your data sheet which JonSea was kind enough to look up. Find your exact relay based on the dash number of the full part number. JonSea was also kind enough to hilight the coil power consumption. Divide your coil voltage into the coil power to get the coil current. For example 0.9 / 12 = 7.5 mA, 1.4 / 12 = 117 mA and 1.5 / 12 = 125 mA.

Ron
 

Jeffrey Screen

New Member
Well thank you All for being so helpful. My mind is still blown! But at least you tried!
Use a relay that latches both ways then. Only requires a pulse of power to the coils to change states (though power is still consumed by the main thing which usually dwarfs the coils power).

what is the relay powering and what is it being controlled from?
What relay are you referring to. How would I look one up. Thank you. If this is really an option it may just fix all my issues
 

dougy83

Well-Known Member
What relay are you referring to. How would I look one up. Thank you. If this is really an option it may just fix all my issues
As mentioned above, your motor would generally use much more power than your relay, to the point of the relay power consumption being negligible. A relay coil doesn't use any power when it's not energised. Using a latching relay will just make things more complicated.
 

crutschow

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The best way to use as little power as possible is to not use mechanical relays but instead use a MOSFET switch or DC output solid-state-relay (SSR) to control the actuator.
 

Reloadron

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With the relays used in the link power is applied to each relay coil for about 1 min. which is one min open and one min close. I would guess limit switches are not required based on the timing for open and close. Once a door is opened or closed there is not power drain other than the timers which are independently battery powered. Chicken coop door open and close schemes are just about endless depending on features wanted and needed. The link seems a simple and viable approach.

Last year a neighbor with several chickens asked me to feed and tend to them when he was out of town. So day one I walk over bright and early, open the coop door and out they all come and start eating the feed I put out. Works for me. That evening I walk over and the chickens are out in their area doing what chickens do but they weren't in the coop! So I wait and as soon as it began to get dark they all went back in and I closed the door. Next day all I did was repeat. Other knowing chickens lay fresh eggs and taste good that was the extent of my chicken knowledge base. Now I know that at dark they return to their coop. Since dawn and dark (hours of daylight) change day to day like street lights the door opening and closing will not be the same day to day. I doubt it would do much good to close a door before the chickens went back in their coop.

Ron
 

Jeffrey Screen

New Member
With the relays used in the link power is applied to each relay coil for about 1 min. which is one min open and one min close. I would guess limit switches are not required based on the timing for open and close. Once a door is opened or closed there is not power drain other than the timers which are independently battery powered. Chicken coop door open and close schemes are just about endless depending on features wanted and needed. The link seems a simple and viable approach.

Last year a neighbor with several chickens asked me to feed and tend to them when he was out of town. So day one I walk over bright and early, open the coop door and out they all come and start eating the feed I put out. Works for me. That evening I walk over and the chickens are out in their area doing what chickens do but they weren't in the coop! So I wait and as soon as it began to get dark they all went back in and I closed the door. Next day all I did was repeat. Other knowing chickens lay fresh eggs and taste good that was the extent of my chicken knowledge base. Now I know that at dark they return to their coop. Since dawn and dark (hours of daylight) change day to day like street lights the door opening and closing will not be the same day to day. I doubt it would do much good to close a door before the chickens went back in their coop.

Ron
The actuator has built-in limit switches
 

Jeffrey Screen

New Member
The best way to use as little power as possible is to not use mechanical relays but instead use a MOSFET switch or DC output solid-state-relay (SSR) to control the actuator.
Can you point me in the direction of a simple wiring Diagram like the one I posted that uses your theory to save power
 

ronsimpson

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As mentioned above, your motor would generally use much more power than your relay, to the point of the relay power consumption being negligible.
The motor is on for 5 seconds to go up and 5 seconds to go down. This only happens once a day.
Depending on how you built the control circuit; the relay might be on 12 hours a day. In this mode the relay might eat more battery than the motor.
If the control circuit turned on the relay(s) for 20 seconds then back off, then the relay coil current becomes of no count.

Most of the Linear Actuators I see on the market are too strong. (250 pounds) I did find a 11 pound one at ServoSity or one of the robot sights. Same price. LOL
I have some linear actuators from reclining chairs and adjustable beds. The chairs get thrown away then dirty. They are 24 volt but come with a power supply. I think they are 250 pound when operated at 10% duty cycle. Where I live used reclining chairs are free.
 

crutschow

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Can you point me in the direction of a simple wiring Diagram like the one I posted that uses your theory to save power
Is that from your #12 post?
If so I really need a schematic, not a wiring diagram, which is specific to that relay module.
 

Jeffrey Screen

New Member
Is that from your #12 post?
If so I really need a schematic, not a wiring diagram, which is specific to that relay module.
He has all the spec listed and links to where he bought the items. Now I feel I’m asking for to much. Thank you for all the help. Have a great day
 
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