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Its true that the SPDT switch is momentary contact but it is an auxiliary to the RF switch. I don't think that the relays are latching as one needs to maintain contact with the SPDT swicth for the lift to move in either direction. When using the RF switch, momentary contact with the transmitter button will activate the lift to travel its full range. Also, with the RF switch it takes two contacts in the opposite direction to start movement in the opposite direction. I'm guessing the first contact releases the relay in the current direction and the second engages the relay in the new direction.You say the lift controller SPDT switch is momentary contact, so presumably the up/down relays in the controller are latching types .
Could be. Or perhaps it's a safety feature to prevent an accidental single press from actuating the mechanism?I'm guessing the first contact releases the relay in the current direction and the second engages the relay in the new direction
Could be. Or perhaps it's a safety feature to prevent an accidental single press from actuating the mechanism?
Understood. That would make a practical 'emergency stop'.
Piggyback Do you mean physically mount them on top? Do you have any particular relays in mind? Spec?
Am I correct, that one mechanism has to operate the other?
e.g. (OPEN)
Door #1 is asked to open
Door #1 opens
Once door #1, activates switch Sc, door #2 is commanded to open.
Door #2 stops on it's own when it reaches a limit.
Door #1 stops on it's own when it reaches a limit
e.g. (CLOSE)
System is asked to close
Door #2 starts to close.
Once door #2 releases switch Sx, then door #1 is asked to close
Door #1 and Door #2 stop at their own limits.
Thus the logic could be broken down as follows:
1. Lock out the remote and manual switches if moving.
2. On rising edge of Sx activate OPEN on door #2
3. On falling edge of Sx activate CLOSE on door #1
If this LOGIC will work, there may be a way to accommodate stopping and starting in mid-stream.
Note: I did not cover how to detect a Rising or Falling Edge or generating the OPEN or CLOSE. I just want to get the logic right. The output from the IR detector could be turned off when needed too.
Sounds like the only way to stop it before a limit switch. Say if you only wanted it half way open or closed.if the lift is stationary and the rf switch is pressed in say the up direction, a relay audibly engages and the lift starts moving. if the down button is pressed a relay audibly clicks (disengaging?) and the lift stops. when the down button is pressed again a relay engages and the lift starts moving down
For when you're only half watching TV and have your mind on other things?Say if you only wanted it half way open or closed.