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Also you have to consider safety when power fails or solenoid fails. otherwise some one is going to be trapped inside the lift.
Fail safe configuration is to use energized solenoids to keep it locked.
The terminals actually have real circuit numbers and therefore have "suggested" polarities. Some relays have a built in diode to absorb the collapse of the coil when you drive it with mosfets or transitors. You can solder a 1n400x (50 v or greater PIV) reversed biased at the relay.
It's easy to figure out how it's wired or works. The Common of each relay goes to the actuator. The NC (Normally Closed) contact goes to ground.
At this point or the rest position, both sides of the actuator are grounded, so nothing happens. Well, acttually something does. If the DC motor is moving and unloaded, it's generating a voltage, but it isn;t so it's generating a voltage into a short for a short time. This has the effect of instantly stopping the motor.
Now, let's connect one of the NO (Normally open) contacts to +12. If we energize that relay, there will be a motor connection from + to ground.
So, let's connect the other NO contact to +. If we energize this relay, there will be a motor connection from + to ground, but in the opposite direction.
With BOTH relays activated there will be +12 on both sides of the motor or 0V across the motor, so the motor doesn't move.
You can interchange +12's and grounds and get the same "effective" result. Movement and braking.
==
Relay activation. In the real documentation somewhere the numbers on the terminals refer to a circuit and therefore have meanings. I can dig up the info.
So, your choice is whether you want a contact closure to ground or one to +12 for activation. The coil has a suggested polarity because some relays have a built in diode across the coil to absorb the back EMF.
==
Aside: When you do motors, your typically using a limit switch that is not rated for the motor current and therefore we have to do additional things. If you used limit switches you can arrange things so continuous LOCK or UNLOCK signals can be used and no power is used when at either position.
Searching for "chicken coop doors" will bring up interesting threads here and elsewhere.
With the motor actuators, you can have a string or wire that when pulled can release or activate the lock. You just don;t want them t get stuck on. I never tried to size a PTC thermal motor protector for one.
I did buy a couple of them, but I used a huge solenoid in a car I had. Door unlocking was useful when i had an alarm system and no OEM electric locks. I added a switch that would optionally not open the passenger door.
The terminals actually have real circuit numbers and therefore have "suggested" polarities. Some relays have a built in diode to absorb the collapse of the coil when you drive it with mosfets or transitors. You can solder a 1n400x (50 v or greater PIV) reversed biased at the relay.
It's easy to figure out how it's wired or works. The Common of each relay goes to the actuator. The NC (Normally Closed) contact goes to ground.
At this point or the rest position, both sides of the actuator are grounded, so nothing happens. Well, acttually something does. If the DC motor is moving and unloaded, it's generating a voltage, but it isn;t so it's generating a voltage into a short for a short time. This has the effect of instantly stopping the motor.
Now, let's connect one of the NO (Normally open) contacts to +12. If we energize that relay, there will be a motor connection from + to ground.
So, let's connect the other NO contact to +. If we energize this relay, there will be a motor connection from + to ground, but in the opposite direction.
With BOTH relays activated there will be +12 on both sides of the motor or 0V across the motor, so the motor doesn't move.
You can interchange +12's and grounds and get the same "effective" result. Movement and braking.
==
Relay activation. In the real documentation somewhere the numbers on the terminals refer to a circuit and therefore have meanings. I can dig up the info.
So, your choice is whether you want a contact closure to ground or one to +12 for activation. The coil has a suggested polarity because some relays have a built in diode across the coil to absorb the back EMF.
==
Aside: When you do motors, your typically using a limit switch that is not rated for the motor current and therefore we have to do additional things. If you used limit switches you can arrange things so continuous LOCK or UNLOCK signals can be used and no power is used when at either position.
Searching for "chicken coop doors" will bring up interesting threads here and elsewhere.
With the motor actuators, you can have a string or wire that when pulled can release or activate the lock. You just don;t want them t get stuck on. I never tried to size a PTC thermal motor protector for one.
I did buy a couple of them, but I used a huge solenoid in a car I had. Door unlocking was useful when i had an alarm system and no OEM electric locks. I added a switch that would optionally not open the passenger door.
Great explanation thanks!
I guess I was thinking of a "normal" type of relay rather than automotive purely for mounting method and aesthetics as they will be going on this board and looks like I will need 4 in total
That looks nice. You may not know about a control panel construction method that generally uses a 1/4" aluminum plate that comes with the enclosure. You tap holes and mount some items, but most of the items mount on a DIN rail. Then you place wire duct inside the enclosures which gives you a plastic duct with a cover with slots for wires to exit.
It might be hard to understand terminals at first. A terminal block usually has at least one open side. You can stack them end to end and tehn finish with a cover. You can also use separators which are larger covers to group terminals.
You then position each set
Your black relay sockets look like they are DIN rail moutable. There should be like a 35mm milled region on the bottom of the relay and something that might look like a clip that can be moved with a screwdriver.
A couple of comments that I have regarding the technique are:
1. I used 18 AWG stranded but with few strands so that the wire is "stranded", but generally stays in place.
2. Make terminals for the external connections to the enclosure.
3. Keep signal and power as separate feedthroughs.
4. "communication" to other related panels was done with dry contact closures.
5. I made a rule that if I wanted to turn on an indicator in a panel in another room, power for that indicator must come from the local panel. I used relays with 24 VAC/VDC coils (the voltage can be either). These relays take up about as much space as a terminal and were about $20 USD each.
You can effectively wire something and drop it in place sometimes. I had to maintain firestop integrity and integrate with the fire alarm panel.
I'll see if I can find a nice suitable "pretty" relay.
I see you used wire ferrules too. That's not seen too often in the US anyway.
I had an impatient chemical engineer ask "Why does the wiring have to be neat?"
It's probably the same reason why all the wires should not be yellow and unmarked.
i forgot to mention that with "normal relays", you have "check button" and "LED" options. The "check button" allows you to manually mechanically move the contacts with your fingers. The LED option gives you a visual indication that the coil is energized.
Edit: Some aren't even LED. They have a mechanical flag.
That looks nice. You may not know about a control panel construction method that generally uses a 1/4" aluminum plate that comes with the enclosure. You tap holes and mount some items, but most of the items mount on a DIN rail. Then you place wire duct inside the enclosures which gives you a plastic duct with a cover with slots for wires to exit.
It might be hard to understand terminals at first. A terminal block usually has at least one open side. You can stack them end to end and tehn finish with a cover. You can also use separators which are larger covers to group terminals.
You then position each set
Your black relay sockets look like they are DIN rail moutable. There should be like a 35mm milled region on the bottom of the relay and something that might look like a clip that can be moved with a screwdriver.
A couple of comments that I have regarding the technique are:
1. I used 18 AWG stranded but with few strands so that the wire is "stranded", but generally stays in place.
2. Make terminals for the external connections to the enclosure.
3. Keep signal and power as separate feedthroughs.
4. "communication" to other related panels was done with dry contact closures.
5. I made a rule that if I wanted to turn on an indicator in a panel in another room, power for that indicator must come from the local panel. I used relays with 24 VAC/VDC coils (the voltage can be either). These relays take up about as much space as a terminal and were about $20 USD each.
You can effectively wire something and drop it in place sometimes. I had to maintain firestop integrity and integrate with the fire alarm panel.
I'll see if I can find a nice suitable "pretty" relay.
I see you used wire ferrules too. That's not seen too often in the US anyway.
I had an impatient chemical engineer ask "Why does the wiring have to be neat?"
It's probably the same reason why all the wires should not be yellow and unmarked.
Thanks for the encouragement! I build kitchens for a living so well out of my comfort zone.
The control panel I built myself using material I had and considered the din rail (actually bought a length then took it back), then realised only the 2 relay mounts and the circuit breaker were rail mountable so didnt bother.
I drilled holes in the white cable duct (that I had) to bring the wire connections through and used bootlace ferrules to make it look pretty lol. Someone on here suggested to leave room for expansion and there is enough room for another row if needed.
In the US, the NEC has certain classes of wiring. Like Class 1, Class 2 and class 3. Class 2 would be for, say a doorbell or HVAC thermostat circuit. I know your not in the US.
In the system I used a large conduit for he low voltage stuff and I put a junction box above the suspended ceiling. It was there, I put similar strain reliefs that you used and then used fire alarm cable (Teflon insulated) to connect to my stuff.
There are plenum rated cables that are used for air spaces and they prevent fires from going from floor to floor. The cabes don;t give off noxious fumes when they burn.
Hello punters, still dodging along with this project as time allows!
Am hoping someone has good suggestions for a switch. I have wired up the actuators using 2 car horn relays to confirm all working ok before trying to nut out the panel mount relay. Everything is working well and am using a SPDT rocker switch to control the actuators. What I need to do is set up a switch so the lift carriage passes by and controls the actuators. So when the carriage goes up (maybe 300mm off the ground) it will lock the lower door. When it returns to the lower floor the switch will unlock the door. Same applies for the top floor. What type of switch can I use that the carriage can activate on the way past up & down? Switch needs to return to centre after the lift passes. So a momentary on/off/on SPDT . Is there a limit switch type of switch with a lever that can do this?
Thanks!
I think they are an on/off switch? Needs to be momentary on but double throw, on/off/on, and be able to be activated as the lift passes upwards or downwards, that's why I was thinking of a limit switch type of roller lever that resets to off after the lift passes
As a pin ot protrusion on the lift car moved past, it engages between the rollers and moves the switch.
There should be two contacts, one operated either side and both on or both off when in the centre position - the lift aligned with the floor.
The switch stays at whichever side of its travel it's last pushed to.
As a pin ot protrusion on the lift car moved past, it engages between the rollers and moves the switch.
There should be two contacts, one operated either side and both on or both off when in the centre position - the lift aligned with the floor.
The switch stays at whichever side of its travel it's last pushed to.
Nearly perfect! Now it just needs to be non-latching with a spring return to off and single lever so the pin protrusion on the lift can operate it either way
Here is the wiring diagram for the switch, one throw direction extends the lock mechanism, the opposite throw retracts it. A rocker switch works perfectly but not possible to actuate the switch with the lift
The purple & green trim wire go to the door lock actuator
The type I listed are suitable for determining if the platform is already at the requested level (so the door can open), or needs to run up or down to reach the level. They "remember" which way the lift is in relation to each switch.
That's what I thought you wanted after the mention of it operating with the lift passing up or down.
To operate purely at a single point position and not have any direction sensitivity, a simple "roller plunger" switch can work with a rounded or tapered cam striker.
eg.
**broken link removed**
**broken link removed**
The type I listed are suitable for determining if the platform is already at the requested level (so the door can open), or needs to run up or down to reach the level. They "remember" which way the lift is in relation to each switch.
That's what I thought you wanted after the mention of it operating with the lift passing up or down.
To operate purely at a single point position and not have any direction sensitivity, a simple "roller plunger" switch can work with a rounded or tapered cam striker.
eg.
**broken link removed**
**broken link removed**
The actuators work with just a "pulse" signal. I have thought about just using a plunge or roller type limit switch but I would need 2 for each floor? One to detect the down motion of the lift and one for the up motion. With the ground(-) and switch wire (from 85 or 86) connected to the NO contacts. Was hoping to use a single limit switch to detect both directions. So the switch needs to be on/off/on (the 2 "ons" are the two different directions) Hard to explain!
Once the lift / platform is away from the switches, you cannot tell which way it moved unless there is a mechanical latch or toggle of some sort to indicate that; that's why the double-roller type are used in positioning applications.
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