Timer and drop bolt question

Thread Starter

Jlames

Joined May 19, 2017
12
Please forgive my ignorance but I’m retired and truly a complete noob. I’m looking to find and match a battery-operated, 12v digital or analog timer with a simple drop bolt lock, like a door bolt, such that a time may be set to send a signal to the drop bolt to open at that time. It may be as simple as a pool timer but again, I‘m a novice in electronics. I was thinking of something like a landscaping transformer but I think that provides a continuous electrical flow to the lock for a specified time and I don’t think that’s what I need. I believe I need a device that sends something like a .5 or 1 second pulse to trigger the bolt to recede or “open” and then return to its original “closed” state.
 

MrChips

Joined Oct 2, 2009
21,666
In order to understand your question let us try to break it down into its components.

1) You need an electrically operated dead bolt, what we would call a solenoid. You need to source the dead bolt and tell us the voltage and current needed to operate the solenoid.

2) You need a "one-shot" circuit that will apply power to the solenoid for 1 second.

3) You need a time-of-day timer that the user can set so that it will open the bolt at a preset time of the day, once every 24 hours.

Am I on the right track?
 

Thread Starter

Jlames

Joined May 19, 2017
12
Yes, you are correct. I need a way to set a simple timer to trigger a simple door lock to open every day at, say, 0800. I’ve looked online for possible, existing pairs but can’t find anything. And thank you for your response.
 

MrChips

Joined Oct 2, 2009
21,666
I would first look at acquiring item (3) a battery operated irrigation timer which can be repurposed for your application.
The next would be item (1) the dead bolt and solenoid and figure out how you are going to power it.

The alternative is to search for a ready-made solution.
 

Thread Starter

Jlames

Joined May 19, 2017
12
The chicken coop solution looks close but, unless I missed something, it involves a photocell. Is there a timer device that would simply deliver a pulse To trigger a solenoid? My intended purpose is to set the timer to actuate a solenoid that releases a trap door in a chute to drop a flake of alfalfa into a feeder for my horses. And thanks for all your work in responding.
 

Thread Starter

Jlames

Joined May 19, 2017
12
Well, yes except this tells me that I can set, either at P1 P2 or P3, a timed event for on and off however each event has to be at least one minute. This would be great if I could set it to one second. There has to be a way to do this either on a 24 hour clock or an a.m. p.m. clock that allows me to set a timed event for 1 second duration; perhaps a time delay relay with a potentiometer in the relay that can be set for 1 or 2 Le ever 3 seconds. I’m convinced there has to be a way to do this; that somebody has figured out. I just don’t have the electronics smarts to do it. Maybe replace the relay in your video with something like the time delay relay here. What do you think? Again, thanks so much for your help.
 

Thread Starter

Jlames

Joined May 19, 2017
12
Well, I just tried an irrigation timer and it’s constant for a specified time period and I need a 1sec pulse.
 

MrChips

Joined Oct 2, 2009
21,666
Don't be totally obsessed in saying "I’m convinced there has to be a way to do this; that somebody has figured out. "

This is not rocket science. Most of the regulars here on AAC can do this in their sleep. Sure there is a solution. It is a matter of finding the easy and right solution for your situation.

1) First solution is to find an off-the-shelf solution that you can buy and connect on your own.

2) Second option is to buy an off-the-shelf timer that you can repurpose for your application. No one here is going to be in a position to come and install the unit for you.

3) Many regulars here have the know-how on how to program an Arduino microcontroller to accomplish what you want to do. We understand that you are not in such a position and therefore anyone of us would be reluctant to undertake a long distance project with someone new to electronics.

Assuming that option (1) is not available, the next best solution is to purchase a battery operated irrigation timer. Every such timer I have examined will allow you to activate a water valve for a minimum if 1 minute. If you can work with that then that is your solution.

If you must have a 1-second activation, then there is a simple 555-timer circuit that will output the desired 1-second pulse. If you dare to choose this route then you will have to do some electronics construction on your own, or get someone with experience in this area to assist you.
 

Thread Starter

Jlames

Joined May 19, 2017
12
Thank you. I meant no disrespect. Perhaps I’m simply not explaining it correctly. I’m trying to figure this out on my own and thus trying to learn how to do it without buying an off the shelf solution; just the right off the shelf parts. And when I say, “I’m convinced there has to be a way to do this; that somebody has figured out.” that was only my way of saying, with more than a degree of frustration, “This can’t be rocket science. What am I not getting? I’m not an idiot.” Again, I’m probably not explaining myself well using a poor choice of words. I’m a retired, 32-year federal law enforcement pilot with 49-collective years in a cockpit including military, commercial and instructional work with students and possessed of a fairly good grasp of understanding instruction. I simply need some direction which is why I’m visiting the various boards. I don’t expect anyone to come to my rescue or enter into a long distance project with me. I‘m simply trying to explain what I’m trying to accomplish and understand where I might find the device or devices that will help me effect that result. So far, I’m finding something like this
https://www.mpja.com/Time-Delay-Module-Adj-0-10Sec-Delay-on-Make-12VDC/productinfo/33421+RL/
to pair with some sort of a timer to effect my solution; but I’ve learned that this in my limited understanding, is close to but not exactly what I need. So, all I’m looking for is a little patience and direction. Again, I’m a “noob” to electronics only; not a lazy, teenage troll looking for a quick-fix. I’m just a fairly intelligent, truly appreciative individual looking for a hand in helping me understand how I can effect a solution to my dilemma. If I’ve offended you or somehow led you to believe that I’m looking for something else, then I apologize. And again, thank you for all your responses thus far.
 

Thread Starter

Jlames

Joined May 19, 2017
12
Also, I thought of the irrigation timer, even a garden light transformer, but both of those deliver a stream of current for a specified amount of time beginning with 1-minute. That type of a continuous current would, I believe, burn a solenoid out, hence my 1-second requirement just to retract and quickly release a bolt or solenoid. If either of those timers work, my problem would be settled. But, as I said, I’m looking to be able to understand the problem and then solve it. If I can understand how the electronics work, then I could develop a solution. I’m assuming an Arduino is similar to a Rasberry Pi that I’m trying to understand now.
 

MrChips

Joined Oct 2, 2009
21,666
No offense committed.

The nice thing about AAC forums is that there are many members chiming in and someone will come up with some leads or bright ideas.

So before we go off the track here are some things you need to consider.

1) What solenoid have you selected? What are the voltage and current requirements of that solenoid.
A solenoid will not burn out if you leave it on forever. They are designed to accept the power stated in the datasheet.

2) How are you going to power the electronics and the solenoid? If you have 120VAC available then it would be nice to know that.

As I alluded to above, someone has given you some leads, example, MPJA - Marlin P. Jones and Associates.
Now you know of one U.S. based source where you can buy an electronic timer module and a 555-timer relay module. Put the two together and you may have found your solution.

Another electronics parts supplier is Jameco in California. You can search for solenoids there.

Here is an adjustable timer that can turn on a relay for 1 second.
https://www.jameco.com/z/MK111-Velleman-Adjustable-Interval-Timer-Kit_2265311.html?CID=MERCH

Thus, there are ready-made solutions for energizing a solenoid for 1 second or any length of time you choose.
 

Thread Starter

Jlames

Joined May 19, 2017
12
Thank you. I’ve been going through the various MPJA videos in my search, and from those I’m starting to get the idea. I haven’t settled on a solenoid nor a voltage. Relative to 110v, yes it’s available but it seems to me that, just needing to trigger a trap door’s latch to retract for a second allowing that trap door, weighing in at only a pound or two, to open dropping some feed into our horses’ feed bin, that perhaps 110v might be overkill. Of course, I have no idea what “overkill“ would be but I would think, with the trap door’s weight not creating an inordinate amount of retention friction, that a simple 12v power supply to the timer to the relay to the latch would be sufficient. It’s going to look like a Rube Goldberg rendering but this is what I’m trying to do.
 

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MrChips

Joined Oct 2, 2009
21,666
If you want to open and close a trap door then using a solenoid is not the best way to do it. A motorized mechanism uses less power and is more reliable. There are low voltage motors (6VDC for example) which can turn an arm to open and close a door. There is no need to reverse the direction of the motor.
 
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