Hi, all I'm Chris. I'm new here and new to electronics.

I'm a carpenter by trade and have been asked to design a hidden door.

The hidden door mechanics took me a while, but I sorted it out. I've built many hidden doors, but never one that was electrically actuated.

After months of on and off research, I finally managed to figure out a wiring schematic that seems to work.

But I would sure appreciate some input to fine tune it.

I've searched and read many posts that seemed to be relevant to my project, but couldn't quite find what I'm looking for.

I'll start by adding a PDF of my schematic (see below I guess).

Here are a few links as to how the door works.
https://www.flickr.com/photos/c_j_ryan/29142911852/in/dateposted-public/
https://www.flickr.com/photos/c_j_ryan/29188845702/in/dateposted-public/
https://www.flickr.com/photos/c_j_ryan/29172640271/in/dateposted-public/

I'm not sure what else to add, parts list maybe?
Power Supplies:
VCDHS DC 12V 10 A https://www.amazon.com/gp/product/B019OIGY4O/ref=oh_aui_detailpage_o07_s01?ie=UTF8&psc=1
VCDHS DC 24V 8 A https://www.amazon.com/gp/product/B019OOTL7A/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
Relays:
http://www.relay-rayex.com/proimages/LB_SERIES.pdf
http://datasheet.octopart.com/S89R11APP1-120-Tyco-Electronics-datasheet-7084775.pdf
Actuators:
https://www.firgelliauto.com/products/feedback-rod-actuator
https://www.firgelliauto.com/products/heavy-duty-track-actuator

So... do I need diodes on the relays? Do I need to fuse this? What am I missing?

As I said in my opening, I am a carpenter. Not a candidate for a degree in EE.

Thanks,

Chris

 

This is not really electronics as the system is just DC power, relay/limit/control switches and DC motors so rest easy. At a minimum you need current protection on the AC power line input to the DC power supplies. I recommend a separate protection on each motor drive circuit with maybe a slow-blow circuit breaker in the case of a track stall and another 'fuse' for the switching control circuit to protect the wiring and switching in case of a short.

Yes, you should use have diodes on the normal relay coils. You can also buy DC relays with built-in coil diodes.

 

Thank you nsaspook,
I really appreciate your response.
As I stated, I'm just a carpenter. Could you expound upon your statement "This is not really electronics" as the system is just DC power?
What type of current protection on the AC power line input to the DC power supplies do you suggest I need?

If I fuse the motor drive circuits, what criteria should I use for amp rating?

I've looked for DC relays with built-in diodes, with no success. Could you recommend some (or one) that suits my voltage and amperage situation? And has a, ok I'm stumped, a footprint like an eight pin connector? Sorry, I just don't know all the jargon.

This is what I've got so far. (see attachment)

 

1. Do you have any problems with motor over run? We can fix that.

2. Is the hidden switch contacts rated for 260 mA or greater.

3. Call the "latching relay" an "impulse relay".

4, You should put a diode across the impulse relay.

5. The DC supply could just be a box and not transformer-like.

6. A breaker to protect against for a failed limit switch.

It seems like you have some sort of double motion.

I put a blurb together here: https://forum.allaboutcircuits.com/...oof-window-control.134958/page-2#post-1131056

 

"This is not really electronics" means it is Electromechanics.

The circuit will run without the diodes for testing but for long term reliability of the switch contacts (they reduce contact arcing) it's a good idea. You can install the diodes on the relay socket screw terminals. Connect the band end of the diode to the + wire coil terminal (7 on your diagram) and the other end to 8.

As for AC fusing, check the power supplies, they might already have internal fuses so you might not need extras.

The motor specs have the 12vdc motor with a max draw of 5 amps and the 24vdc motor at 3 amps so use 150% to 175% of those values for DC motor fuses.

 

What is not clear from the schematic is what you want the system to do. If the task is to open and close a door, the schematic seems a bit complicated. If the motors are DC, are they reversible? If so, why are there two motors for only one door?

ak

 

What is not clear from the schematic is what you want the system to do. If the task is to open and close a door, the schematic seems a bit complicated. If the motors are DC, are they reversible? If so, why are there two motors for only one door?

ak

He's using a bistable impulse latch relay to reverse directions with limit switch logic to sequence. One motor seals/unseals the rack to frame forward/back and the other to moves the door in/out on the track. Fairly standard for old school sliding hidden door applications.

 

1. Do you have any problems with motor over run? We can fix that.

2. Is the hidden switch contacts rated for 260 mA or greater.

3. Call the "latching relay" an "impulse relay".

4, You should put a diode across the impulse relay.

5. The DC supply could just be a box and not transformer-like.

6. A breaker to protect against for a failed limit switch.

It seems like you have some sort of double motion.

I put a blurb together here: https://forum.allaboutcircuits.com/...oof-window-control.134958/page-2#post-1131056

 

What is not clear from the schematic is what you want the system to do. If the task is to open and close a door, the schematic seems a bit complicated. If the motors are DC, are they reversible? If so, why are there two motors for only one door?

ak

Watch his video, first link in post #1.

 

Thanks all, I'm just learning your forum also. Just spent 20 minutes replying to Keep It Simple Stupid, and when I went to post discovered the 10-minute edit limit and lost it all! LMAO! Forgive me I'll know better next time! OK, Back to recomposing my responses!

Chris

 

On this forum, it will usually come back. You just have to navigate back to where you started to compose, initially the text will be there greyed until you click on it.

Sometimes you have to go through some hoops to get there especially when replying to a post the first time, because you have to navigate back to the thread.

BTW KISS works for KeepItSimpleStupid unless you want to "tag" me.

 

I have a question / suggestion. What happens in the event of power failure? Since I don't know your geographical location and the reliability of AC mains supplying your 12 and 24 VDC power supplies I was just wondering what happens during a power failure? If you don't need a provision for that it's cool but I was just curious. I believe everything else has been addressed and it seems to run and work just fine. Pretty cool door.

Ron

 

I have a question / suggestion. What happens in the event of power failure?

Ron

A cheap UPS should handle that problem but if the power fails without one then the orgy behind the door just continues in the dark.

 

Gee, I thought it might be the dungeon?

 

Gee, I thought it might be the dungeon?

Orgy in the dungeon behind the 'Green' door.

 

Orgy in the dungeon behind the 'Green' door.

Classic stuff.

Ron

 

1. Do you have any problems with motor over run? We can fix that.

2. Is the hidden switch contacts rated for 260 mA or greater.

3. Call the "latching relay" an "impulse relay".

4, You should put a diode across the impulse relay.

5. The DC supply could just be a box and not transformer-like.

6. A breaker to protect against for a failed limit switch.

It seems like you have some sort of double motion.

I put a blurb together here: https://forum.allaboutcircuits.com/...oof-window-control.134958/page-2#post-1131056

Ok KISS,
I will start again.

1. I shouldn't have overrun problems as the linear actuators have built in limit switches and I designed the mechanical portion of the system to have enough adjustment to allow for full extension and retraction of them.

2. That's a very good question. I have no idea what the switches are rated at. There are three by the way. A momentary contact switch, a reed switch and a keyfob type remote. They are all basically momentary contact switches. 260 mA, is a fairly small draw, or so it would seem. How did you determine that number?

3. Yes, it is am impulse relay, sorry. I started out with the idea of using a latching relay but it just added more relays, and I'm trying to keep it simple.

4. Good point I hadn't considered "flyback" from that. So you think there will be a chance there, and I need a diode? How should that rating be determined?

5. I already have those transformers, am I missing something? Other than being a bit more expensive than "a box" as you call it, do you see an issue with their use?

6. I have some automotive type fuse holders that I was going to install in line on the actuators, I hadn't even thought about breakers, which would be much more convenient. I'll have to look at some.

Yes, you are correct, it is double motion.

I've glanced at you "blurb", but haven't had the time to fully understand it all.

Thank you for your response,

Chris

 

"This is not really electronics" means it is Electromechanics.

The circuit will run without the diodes for testing but for long term reliability of the switch contacts (they reduce contact arcing) it's a good idea. You can install the diodes on the relay socket screw terminals. Connect the band end of the diode to the + wire coil terminal (7 on your diagram) and the other end to 8.

As for AC fusing, check the power supplies, they might already have internal fuses so you might not need extras.

The motor specs have the 12vdc motor with a max draw of 5 amps and the 24vdc motor at 3 amps so use 150% to 175% of those values for DC motor fuses.

Thanks for the follow-up post nsaspook,

I appreciate the advice as to the diode hookup.

I will do some research as to my power supplies having internal fuses.

One thing that was not clear on my schematic is the there are two 12vdc motors, there is a lower and upper mechanism. I have checked the operating amperage and although I'm sure it's higher at the start up I've never seen more than 3 amps once per motor during "normal" running. I do not have a top of the line multimeters, but that's what I'm getting. Do you have a change in opinion on the fusing with that additional knowledge? I could fuse them individually, but I'd rather the both stop if there was an issue.

As to not add as an extra post, I did get a chuckle from your "old school sliding hidden door applications", although I know I'm not re-inventing the wheel, I'm curious as to what a "new school" technique would be?

And thank you all for your time and patience with a new poster that doesn't even know the difference between "electronics" and "electro-mechanics" *wink*. If you guys ever need help with carpentry...just holler!

 

I don't see a problem with a single fuse of the correct amperage for both motors

I've worked on lots of older seal door systems where there are separate actuators for seal/unseal and open/close. Most modern systems use a cam-over or auto-lock pressure seal operated from one actuator.

Great job on that woodwork.

 

I have a question / suggestion. What happens in the event of power failure? Since I don't know your geographical location and the reliability of AC mains supplying your 12 and 24 VDC power supplies I was just wondering what happens during a power failure? If you don't need a provision for that it's cool but I was just curious. I believe everything else has been addressed and it seems to run and work just fine. Pretty cool door.

Ron

Shouldn't be a problem, they have a 200 Kw back up generator.