Remote Control 12v relay

[Genner]

Hello everyone,


I'm planning on adding some sort of remote control function that can push and pull the locking latch mechanism(it's like a deadbolt) on my garage door. I am thinking an actuator with a 12volt remote controlled relay. I've seen some of these type of 12volt remote control relays on ebay and amazon.

However the only thing I cannot figure out is how to auto stop the actuator from continuing once the latch has been fully pushed or pulled. I would like the relay to stop powering the actuator automatically once the actuator encounters resistance from either pushing the locking latch to it's max and/or pulling all the way back when unlocking. The throw distance of the lock is about 2".
I know some of the 12 volt remote relay kits have momentary and latching features when you press the buttons on the remote keyfob and I think I am leaning towards the latching mode but some how have the relay circuit stop the actuator on it's own.
I don't prefer the momentary option because I won't be able to see the latch as it will be inside the garage when I pull up onto the driveway.

I've also seen some 12volt relays with a configurable timer on it that will keep the actuator on for that set time, but I'm not sure how this will work out in my scenario.
If anyone has any other ideas please help.

Thanks,
Genner

 

[large_ghostman]

Can you post a pic of what device you intend to use please, I cant give an answer without knowing exactly what you want to use. But it should be fairly straight forward once we have an idea what you are calling a actuator etc.

And welcome to the forum

 

[Genner]

Hello Little Ghostman,

Thanks for replying back to my post.

Here is a link to the 2 channel remote 12 volt relay with delay timer:

**broken link removed**

here is the actuator I was referring to:

http://www.amazon.com/Stroke-Actuat...id=1456046831&sr=8-3&keywords=12volt+actuator

I also saw these on amazon as well. It is just a multifunction timer relay but without the remote control:

http://www.amazon.com/Puuli-FRM01-1...&sr=8-1&keywords=12volt+2+channel+relay+timer


Sorry if the pictures are too large. Not sure how to resize them from a link.

Thanks for your help!

 

[alec_t]

However the only thing I cannot figure out is how to auto stop the actuator from continuing once the latch has been fully pushed or pulled.

According to the actuator spec it has built-in limit switches.

 

[Genner]

Hello Alec_t,

Good catch I never even saw that. With the limit switch, does it auto stop anywhere up to 2" if it encounters resistance once it cannot push or pull back the latch? Or is it like a manual adjustment where you set the limit of the actuator and once it reaches that setting anywhere up to 2" it will auto stop?
If the second scenario is the case, I'm assuming when i hook it up to the remote control module, I can use the latching method without a timer and the actuator will turn itself off. Then if I needed to reverse the latch will the actuator turn on?

 

[alec_t]

My guess is that they are non-adjustable and simply go open-circuit at either end of the stroke. I couldn't see any description of limit switch characteristics. Perhaps you could contact the maker/supplier?

 

[AnalogKid]

The actuator is a motor-driven lead screw or worm gear drive. It looks like there are only two power leads. There is a limit switch trick that requires two diodes that makes this work, and all of that probably is built in. Connect DC one way, motor runs until it hits one switch, then stops. It moves again only with the DC is reversed, when it runs until it hits the other limit switch. So, your control system needs to be able to reverse the DC polarity to the actuator to get it to move both ways.

If you want a push-push, auto reversing system, then you need a toggle flip flop function somewhere. If you want to wire up something, this can be a couple of transistors, or a single CMOS IC and some driver transistors. If you don't want to wire up something - what is wrong with you??? OK, seriously, you're in luck. An impulse relay does the toggle and power switching all in one part, no soldering.

If you want a more directed control system, with one lock button and one unlock button, that might be doable with the board in post #3.

*whap* ball's in your court.

ak

 

[MaxHeadRoom78]

For the retract use the internal L.S.
For the extend you could fabricate a spring loaded support at the rear end of the actuator, when the actuator strikes the door in the forward motion it compresses the spring and closes a L.S., normally those type of actuators do not back-feed so it should stay that way until retracted.
Max.

 

[Les Jones]

Hi Genner,
I have two suggestions.
1 Make the linkage between the actuator and the bolt using a pin engaging with a slot. This will mean that the actuator has to move further than the travel of the bolt. If you make the length of the slot adjustable with sliding plates at each end then you could use the internal limit switches.
2 If you want to stay with the overcurrent detection system you could use part of the circuit below.

You would just use the comparator circuit at the right of the schematic to detect the motor current. The 2.7 ohm resistor would need to be changed to suit the current taken by your actuator. If you wanted the same current limit in both directions you would only need one comparator. (An LM393 would be OK - I only use the LM339 as I had it in stock.) The reversing is done with two single pole change over relays. One for each direction. If you wanted to use two comparators to give different current limits for each direction then you would put a sense resitor in the negative supply to each relay. The capacitor on the input of the comparator is to prevent the motor starting current from triggering the comparitor. The output of the comparator would drive a transistor that provided power to the motor. Note these comparators require a pull up resistor on the output. (They are open collector outputs.)

Les.

 

[KeepItSimpleStupid]

You can arrange 2 relays so one is lock and the other unlock. If the pulse is long enough the motor will stall.

What you can do is monitor the mechanism for say 30s after a command is send and indicate the status. Say red/green or just green.

Red/grn would indicate a jam if it's not in the full position.

A polyswitch mounted to the motor and sized properly would protect against overloads.

Be aware of fail safe and fail secure and how you would enter without power or stuck (both lights off).

So Im suggesting state visibility for a short time after actuation.

 

[KeepItSimpleStupid]

You can arrange 2 relays so one is lock and the other unlock. If the pulse is long enough the motor will stall.

What you can do is monitor the mechanism for say 30s after a command is send and indicate the status. Say red/green or just green.

Red/grn would indicate a jam if it's not in the full position.

A polyswitch mounted to the motor and sized properly would protect against overloads.

Be aware of fail safe and fail secure and how you would enter without power or stuck (both lights off).

So Im suggesting state visibility for a short time after actuation.

 

[KeepItSimpleStupid]

ps. I was thinking along the lines of a power door lock actuator which is typically a motor and a rack.

Lineear actuators either use a pulse system, non-adj limits or potentiometer feedback.

 

[MaxHeadRoom78]

I never like stalling motors to detect and end stop, I think the L.S. is a better solution.
Max.

 

[AnalogKid]

Trading electronic effort for mechanical effort, one approach is to adjust the external mechanical environment so the actuator's internal limit switches engage at the necessary positions.

ak

 

[KeepItSimpleStupid]

Linear actuators are just plain weird. They are way too powerful, bt don;t have easily adjustable limits.

A power door lock linear actuator is a different beast altogether. And really cheap. e.g. https://www.amazon.com/High-Power-Door-Lock-Actuator/dp/B0088YE6YQ

It's also easily moved by the motor and the by pushing on the mechanism unlike the leadscrew.

 

[large_ghostman]

This never popped up on my answer list!! sorry about that!! I have only just seen it.

 

[4pyros]

Use channel A to open and B to close. Both on monetary.
Use latching relays that will unlatch with the limit switches.