Help with time released lid

[markuk75]

Good afternoon all my first post,
I have done a lot with RC stuff in the way of electronics,
but i have been asked to make a Autofeed for a hay box,
so been thiking of an electro magnet that hols the lid down then with a timer it releses the lid sounds easy,
but its in a field so really only have max of a 9v battery really.

So question what sort of timer could i use its only for a once open a day the eveing the next day it will be reset for that eveing, so only need 12 hr max really but 24 could be good,
also as only 9v battery really need a way for it to not use to much power as dont want to be changing the battery every other day,

but with the electro magent holding down the lid the whole time that would use a lot of power, so may be a solinod instaed to relase a lock?
hope that makes sense and any sugestions would be very much apreciated

thanks
Mark

 

[ZipZapOuch]

Good afternoon all my first post,
I have done a lot with RC stuff in the way of electronics,
but i have been asked to make a Autofeed for a hay box,
so been thiking of an electro magnet that hols the lid down then with a timer it releses the lid sounds easy,
but its in a field so really only have max of a 9v battery really.

So question what sort of timer could i use its only for a once open a day the eveing the next day it will be reset for that eveing, so only need 12 hr max really but 24 could be good,
also as only 9v battery really need a way for it to not use to much power as dont want to be changing the battery every other day,

but with the electro magent holding down the lid the whole time that would use a lot of power, so may be a solinod instaed to relase a lock?
hope that makes sense and any sugestions would be very much apreciated

thanks
Mark

9v battery? How about a bank of lead-acid batteries and a solar panel to recharge? A latching solenoid.
What safety mechanisms/procedures would you use to prevent animals from starving if the unit fails?

 

[danadak]

Latching solenoids ?

The Basics of Latching Solenoids | TLX Technologies

What is a latching solenoid, how does it work, and what are its benefits? Learn the basics of the design, operation, and benefits of the latching solenoid.

www.tlxtech.com

Regards, Dana.

 

[markuk75]

9v battery? How about a bank of lead-acid batteries and a solar panel to recharge? A latching solenoid.
What safety mechanisms/procedures would you use to prevent animals from starving if the unit fails?

Hi Zip thanks for reply was thiking about solar but this is for horses so need to make it hard wearing really and cant think of a good way to have the solar panel with out it getting distroyed and dont really know much about solar,
and with safety mech its only for the evenings so if it doesnt open it isnt the end of the world,

Latching solenoid ? i assume works same way as latching relay you dont need power to keep it out or in ?
power to open and stays there power to shut and it will stay there ?
that is an option if can work out a mechanisum

thnaks
Mark

 

[danadak]

Latching solenoids -

A good way to drive use an H bridge that allows easy polarity reversal.

Operation of the Latching Solenoid

What is a latching solenoid? A solenoid is an electromechanical mechanism that moves a plunger in response to an application of an electric current. A latching solenoid provides the same linear motion; however, it includes a mechanism to hold the plunger in a fixed position independent of...

forum.digikey.com

H Bridge driving inductive loads :

H-Bridge with highly inductive load

I am trying to understand the H-bridge, I have edited the circuit and followed the advice in this thread. Is this a good H-bridge design for excitation of the magnetic core which is highly inductiv...

electronics.stackexchange.com

https://www.ti.com/lit/pdf/slva321a

Regards, Dana.

 

[ChrisP58]

I would suggest this type of latch.

It draws no power when holding. It will release with a pulse of less than a second.
Amazon link

 

[markuk75]

I would suggest this type of latch.

It draws no power when holding. It will release with a pulse of less than a second.
Amazon link

Hi Chris
that looks perfect for the job
greta find thanks for that.
Mark

 

[Pommie]

Note: the small (pp3) 9V batteries are only rated at 0.5Ah and can't supply much current (1.5A is a lot).

Mike.

 

[ZipZapOuch]

Note: the small (pp3) 9V batteries are only rated at 0.5Ah and can't supply much current (1.5A is a lot).

Mike.

An Energizer Ultimate Lithium 9v can handle 1A continuous and 3A pulses aren't a problem (but not specified).

https://energizer.com/wp-content/uploads/2023/12/l522-1119.pdf

 

[Pommie]

An Energizer Ultimate Lithium 9v can handle 1A continuous and 3A pulses aren't a problem (but not specified).

And an (insert any brand name) lithium battery is very expensive (Energizer PP3 being over USD10). I was talking about a normal (although still alkaline) battery. Do you really think the OP was specifying a Lithium battery? More likely a carbon zinc battery.

Mike.

 

[Nigel Goodwin]

And an (insert any brand name) lithium battery is very expensive (Energizer PP3 being over USD10). I was talking about a normal (although still alkaline) battery. Do you really think the OP was specifying a Lithium battery? More likely a carbon zinc battery.

Mike.

I suspect he had highly optimistic requirements

 

[markuk75]

so have got the latch now also tried to get a 24hr timer could do with a mechanicel time with a switch
but only need something to give the lock a pulse to open it,

any ideas what i could use for the timer
could use lithium batterys as well as there quite cheap in the uk, also could use solar to charge but not worked with solar before.
thanks everyone
mark