Questions about relay with power-on delay and power-off delay
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As is known about ordinary relays, for example a NO-type relay, when the coil is not energized, the contacts are open; when the coil is energized, the contacts close instantaneously. However, for a NO-type relay with delayed closure upon power application, assuming a delay time of 3 seconds, the contacts close only after the coil has been energized for 3 seconds. My question is whether the contacts will close if the coil is powered for only 1 second. Similarly, for the power-off delay type as well, when the coil is powered off for 1 second and then powered on again, will the coil be disconnected? We know that there are non-latching and latching types in PLCs; we wonder if this functionality also exists in actual relays This post was last edited by we11we11 on 2009-3-30 21:58.]
For the power-off delay type, when the coil loses power and is powered on again after 1 second, the coil will not close; actual relays also have this function.
My personal understanding is that as long as the delay time has not passed, the contact will not move, regardless of whether the coil is powered or not. I don’t know how an actual relay is implemented; someone please explain its principle.
I think the state when powered for 1 second shouldn’t change, since the required time has not yet passed. In fact, the simplest way to find out is to try using a relay!
In fact, for ordinary time-delay relays, those available on the market are all non-latching types; only intelligent relays can achieve latching functionality, and a controller is required for that. For the relay with a power-on delay, set it to 3 seconds; when power is applied for 1 second, the normally open contact remains closed. For the relay with a power-off delay, set it to 3 seconds – when power is cut off for 1 second and then restored, the normally open contact stays in its closed state ； The normally closed contact also remains unchanged, in the open state
For a relay with a power-on delay, set it to 3 seconds; when power is applied for 1 second, the normally open contacts remain closed. For a relay with a power-off delay, also set it to 3 seconds – when power is cut off for 1 second and then restored, the normally open contacts close, but they should be open again when power is cut off
For a relay with a power-on delay, set it to 3 seconds; when power is applied for 1 second, the normally open contacts remain closed. For a relay with a power-off delay, also set it to 3 seconds – when power is cut off for 1 second and then restored, the normally open contacts close, but they should be open again when power is cut off