7 successive relays to trigger themselves

does anyone know how to wire 7 relays, in order to have the first one turn on the second one, and the second to turn off the first and the third one on etc, because i heard that if you were to do this and repeat it seven times, the relays would hold enough power to continue to run off the left over electricity stored inside the coil to run for almost ten minutes or longer. i know its pointless but i wanted to know if there was a way to wire that, and if so how?

its been boggling my mind for some time and would really appreciate and answer.

Thank You.

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Knowing is Half the Battle

I don't see how this would be possible. Most relays are electromechanical devices. When you power the coil it creates a magnetic field that pulls the arm of a contact to the "close" position.

In order to wire up 7 relays to trigger themselves you would apply 12vdc to one side of the coil and ground to the other side of coil of the first relay. You would run 12vdc through pin 87 (NO) and out pin 30 (Common) to the second relay coil (and supply ground to the other side of that coil). You would then continue this setup until all seven relays are connected.

Here is the thing though, the coils, and their supposed energy, are never paralleled or connected together in any way as the magnetic aspect of the relays acts as an isolator.

Most automotive relays require about 160mA of current to stay activated. The coil would have to store up quite a bit of energy to keep even a single automotive relay energized for 10 minutes. On a much smaller relay where coil current is only a few mA it would obviously take much less stored energy but at the expense of having a much smaller coil and smaller contacts.

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Kevin Pierson

Depending on how the relays are "clocked" or triggered, maybe a CD4017 circuit is best - that's a 1 of 10 (output) counter which can be made to count (divide) from 2 to 10.

The problem is what do you use to keep a relay on, and then trigger then next to close (and hence open the others or last)?


As to relays holding enough power to hold another relay on - what bullsh! Coils are inductive and they release a fast spike, and they have negligible capacitance (that could hold voltage).

Besides, as KP wrote, there is no connection between the coil of one relay and the next, so how could they.

[ LOL - reminds me of when I see "of course I don't know what the spike from one relay coil will do to the next" wrt to spike damage. LOL - the spike's originating coil sees the same spike so it would damage itself, and since they don't... Besides, since they do not share the same connection... Yet another case of people thinking, but not thinking clearly. (Or a little knowledge can...) ]