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.

Thank you, nsaspook, but what you are seeing is just a prototype mocked up in my shop for testing purposes. The real one hopefully will look better. And won't have all that harmonic vibration from the rubbing as the door retracts.

You've peaked my interest though. Do you have any convenient links to "cam-over or auto-lock pressure seal operated from one actuator", in that I'd have never heard of them when I was doing my initial research, they somehow escaped me. (Actually, I did sort of think I was re-inventing the wheel, sort of anyway). As I've done a dozen or so hidden doors, I was aware of those little things that give them away. Large gaps at the bottom, gaps between the frame and door/cabinet/ whatever moves.

Chris

 

1. Needs more devoted to answer, skip for now.

2. Coil resistance at the voltage of the relay coil from the datasheet. I=V/R. Relays are slightly inductive.
260 mA is small, but small reed switches are often rated for about 100 mA.

3. Update the diagram text.

4. The diode protects other stuff like the DC power supply. Use >= 2x the voltage of the solenoid and you can use the current of the solenoid as the other limit. So, a 1n4001 would be fine. So would just about any 1n400x diode. Just not 1000 PIV. In an older automotive environment use 400 PIV for other reasons.

4a. A reverse biased diode across the power supply would be helpful too. The motors act as generators.
A series diode will also help protect the supply, This would reduce the power supply voltage a little (0.2 to 0.6V) nd has to be rated 1.5X or higher than the motor current. Again, prevent the DC motor from backfeeding. That's where a discussion of #1 would help too and reduce the need for a series diode.

5. Just update the schematic. A "transformer" is AC in AC out. An inverter is DC in DC out and a power supply has traditionally been AC in DC out. So, the "cartoons" use din your drawing need updating.

6. A breaker probably. A polyswitch is sometimes used to protect motors. They have to be sized carefully. Search on the term.

You might consider, some "what if" situations like a limit switch fails etc. How does one fix the issue?


OK, Briefly for #1. Usually two SPDT relays are used to keep the motor shorted when it's off. You end up with a relay that controls OPEN and a RELAY that controls closed. Nothing happens if both relays are off or both relays are on. Your limit switches can then work on the coil current and not the motor voltage.

In a traditional design, the limit switch contacts would open the drive to the OPEN or CLOSED relay respectively.

As I said earlier, the DC motor acts a generator when turned off e.g. coasting. So, you short the winding of the DC motor when it reaches a limit and turns off. The motor will stop really fast.

The blurb on the other thread has some extra stuff in it and it's drawn in a hard to understand way.
The EXTRAS are a way to determine "fully open" and "fully closed" and a way to detect "moving".
It also uses an application of +12 to drive.

 

1. Needs more devoted to answer, skip for now.

2. Coil resistance at the voltage of the relay coil from the datasheet. I=V/R. Relays are slightly inductive.
260 mA is small, but small reed switches are often rated for about 100 mA.

3. Update the diagram text.

4. The diode protects other stuff like the DC power supply. Use >= 2x the voltage of the solenoid and you can use the current of the solenoid as the other limit. So, a 1n4001 would be fine. So would just about any 1n400x diode. Just not 1000 PIV. In an older automotive environment use 400 PIV for other reasons.

4a. A reverse biased diode across the power supply would be helpful too. The motors act as generators.
A series diode will also help protect the supply, This would reduce the power supply voltage a little (0.2 to 0.6V) nd has to be rated 1.5X or higher than the motor current. Again, prevent the DC motor from backfeeding. That's where a discussion of #1 would help too and reduce the need for a series diode.

5. Just update the schematic. A "transformer" is AC in AC out. An inverter is DC in DC out and a power supply has traditionally been AC in DC out. So, the "cartoons" use din your drawing need updating.

6. A breaker probably. A polyswitch is sometimes used to protect motors. They have to be sized carefully. Search on the term.

You might consider, some "what if" situations like a limit switch fails etc. How does one fix the issue?


OK, Briefly for #1. Usually two SPDT relays are used to keep the motor shorted when it's off. You end up with a relay that controls OPEN and a RELAY that controls closed. Nothing happens if both relays are off or both relays are on. Your limit switches can then work on the coil current and not the motor voltage.

In a traditional design, the limit switch contacts would open the drive to the OPEN or CLOSED relay respectively.

As I said earlier, the DC motor acts a generator when turned off e.g. coasting. So, you short the winding of the DC motor when it reaches a limit and turns off. The motor will stop really fast.

The blurb on the other thread has some extra stuff in it and it's drawn in a hard to understand way.
The EXTRAS are a way to determine "fully open" and "fully closed" and a way to detect "moving".
It also uses an application of +12 to drive.

Thank you!

I might have a better response tomorrow. I'll have to google half of your,recomendations. I get most of it, but again, just a carpenter lost in a new world for me!

Chris

 

Take a look at this note: http://blog.uk.tdk-lambda.com/uk/2014/07/18/when-should-external-diodes-be-used-with-a-power-supply/

And here:
http://dlcparts.com/images/BoschGuide.pdf#page=5 (modified URL to open to the page of the document)

Pretend the actuator is a motor which it is. It doesn't show the contacts and limit switches aren't used with automotive door lock motors.

 

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

That will work!

Ron

 

Bet your jealous?