indicator light for a switch

I have an electric motor that is used to open and close a chute. A switch is used to supply power to solenoids that run the motor. There are microswitches that cut the power to the solenoids from the control switch when the chute is fully open. I want to add an indicator light that shows when the chute is not fully closed and turns off when the chute is closed. Any ideas how to accomplish this? I was thinking using a latching relay is likely the simplest way but I do not have any of them, only some SPDT relays so if there is a way I can accomplish this with them is preferred.

Thanks

Is there any way you can mount a switch somewhere by the chute, and an actuator on the chute that will depress the button on the switch when the chute is closed?

So there is nothing to cut power when the chute is fully closed?

I'll try explaining this a little better with a diagram. I know the diagram is not of the complete circuit but I think it should be the part that is needed for figuring this out.



Everything that is shown after the switch should be included a second time for when the switch is held the opposite direction to open the chute. The microswitch is pushed when the chute reaches full closed to interrupt power to the solenoid to stop the motor. In terms off wiring the simplest idea I had to have a light on is another microswitch in the exact same place as the one that is already there and connect the battery to NC and the light to com, but I do not have room to do this here.

There was a wire connected to the microswitch at NO that somehow turned a light on when the microswitch was pushed. Unfortunately I do not have any of the components that were connected to that wire anymore to know how it was done. If I had that I know it is just a matter of using a relay to turn the light off instead of on.

I had also thought of the microswitch being activated somehow off of the chute but this is on the bottom of a semi trailer so exposure to the elements is an issue.

the switch in the diagram needs to be held to open and close the chute otherwise I would have reversed the wires at the microswitch to put the switch on the common side and the solenoid at NC and then power a relay off of NO to turn off the light.

The point is that if there is open and close position switching, then it should be easy.

In your OP you mention only the fully open switches (hence can have a light when fully open or NOT fully open) but it's the fully closed that was the problem - ie, how to sense that for a light when fully closed or NOT fully closed.

If you run a wire from NO terminal of the microswitch you can use that as a (-) switch, which goes to ground when the chute hits the limit.

If you run a small SPDT relay with the coil connected to the (+) output from the switch and the NO contact of the microswitch (or basically between the NC and NO contacts), you can use that to turn on your light, using the power from the switch for the lamp (+) and the NC contact of the added relay for the lamp (-)
(Connect the COM of the added relay to ground).

This assumes your added relay is low current relative to your solenoid, so that the solenoid can act as a virtual ground. If you have a very low current solenoid, (probably not the case), just find a lower current relay or use solid state components.

You can do the same for the other side, so you'll have indicators for both opening and closing operation-in-progress.

dmaddess wrote:

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There was a wire connected to the microswitch at NO that somehow turned a light on when the microswitch was pushed. Unfortunately I do not have any of the components that were connected to that wire anymore to know how it was done. If I had that I know it is just a matter of using a relay to turn the light off instead of on.

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This description is the opposite of what you seemed to say you were looking for, by the way.

Did you want the light to come on when it hit the end of the travel (pushing the microswitch), or did you want the light to come on only when the motor was active and turn off after it gets to the stop?

yes I am looking for the opposite of what used to happen. The lights that used to be there wee in a box that got damaged and the lights did not work. Seeing as how we got by without the lights already I thought nothing of it. That change recently when about $500 of grain got dumped on the ground because the chute was not closed completely. The way it happened the original lights would not have stopped this from happening because the truck driver was in the truck when it got filled and would not have seen the lights. So I decided I wanted to wire in a light on the dash of the truck so it would be seen but after thinking about it I thought having a light on when the chute is closed would be distracting to the driver which is why I want it opposite to how it originally was. Because I knew there was a microswitch that got pushed when fully closed that turned on a light I was thinking the wire had power on it and all I needed was the relay to reverse it but when I actually paid attention to how things worked I found it was much different.

Using the solenoid as a virtual ground makes sense to me an is what I wondered if they had done before. I think the solenoid most likely is not low current because the motor that it runs is high torque and low speed with the power cables for the system being #4 protected by a 100 amp circuit breaker(two 50 amp breakers connected in parallel)

thanks for the help as I generally know just enough to be dangerous

Well, if you're sufficiently dangerous now, you can give the relay a try then.

I'm pretty sure the solenoid will be more than enough to act as a virtual ground for any standard relay, from the sound of it.  Only thing I wonder is that the microswitch you're using must be a fairly plus sized micro, since it's passing the current for it.  I think of microswitches as the tiny little jobs that you can poke with a pinky-

Just hook it up between the microswitch contacts (NO and NC) and see if the relay switches when you have the power switch turned on and push the microswitch.  If it does then it's simple enough to use the relay contacts to activate your indicator light.