I am building a board similar to the attached image for my employer and I can't seem to figure out how I should wire it. The 4 toggle switches will turn on a red or green light in each of the 4 zones but I need a master switch (keyed) that will disable the toggles so that the lights can not be changed by just anyone unless they have the key.

Thank you for any advice on this project.

 

Most P.B. manufacturers offer a key switch in some form or another such as Digikey stock
CKL13EFW01-002
Place in line with the feed for the other switches.
Similar to this

Max.

 

hi Max,
I think he wants the selected Red/Green lights to stay ON, when the key switch is OFF.?
E

 

If Eric is correct then do you have any experience with small micro's?
It should be a cinch doing it that way.
Max.

 

Yes....I do want the lights to remain on when master switch is off. The master switch is for disabling the toggles but the lights should remain on. No...I am a CNC machine operator and carpenter so I have no experience with micros. So my question really is.....can you have a switch that disables another switch and the thing that is turned on stays on?
Thank you everyone for your input.

 

I don't see it being done with a simple switch that will retain all the present states without some logic, and a hard wired version may get Very messy!
Max.

 

That's what I was afraid of.... So how could someone do it with logic? I'm a pretty sharp guy if I could get a diagram I could build it. Thanks again for your help.

 

Indus

That's what I was afraid of.... So how could someone do it with logic? I'm a pretty sharp guy if I could get a diagram I could build it. Thanks again for your help.

Industrial relays are not cheap, and this might be doable with ladder logic. How much can you spend? Hundreds? Thousands?

 

Is this a One Off or is this for a production item?
A Smart Relay would be one option, but not cheap.
Max.

 

I have to build about 10 of these for a production line. they don't want anybody change in the red lights to green without the proper authority. I guess I will just go to my fall-back position which is to make each one of the toggles a keyed toggle.
Thank you ever so much for your help you guys are awesome.

 

How about 4 SR flipflops using for example 2 CD4011 (Quad NAND gates). This is a very rough sketch of the idea showing just 2 of the 4 flipflops.



The master switch would disconnect the ground from commons of the 4 switches so that the toggle switches could not change the state of the flipflops. The LEDs could be driven using CD4049 or DC4050 buffers or small mosfets.

Les.

 

How about a simple lockable door over the toggles?

 

How about a simple lockable door over the toggles?

I Like that!
Max.

 

How about 4 SR flipflops using for example 2 CD4011 (Quad NAND gates). This is a very rough sketch of the idea showing just 2 of the 4 flipflops.
View attachment 169346


The master switch would disconnect the ground from commons of the 4 switches so that the toggle switches could not change the state of the flipflops. The LEDs could be driven using CD4049 or DC4050 buffers or small mosfets.

Les.

I like this idea....I will look into it. Thank you

 

How about a simple lockable door over the toggles?

That's an awesome idea... I will definitely include that in to the proposal to the company.

 

Here's another option for the logic :-

U1a is a clock oscillator which is enabled/disabled by the master switch. When enabled, outputs 1-4 take up the states of the other switches. U2 is an octal latch circuit to hold those states when the oscillator is disabled.

 

Here's another option for the logic :-
View attachment 169350
U1a is a clock oscillator which is enabled/disabled by the master switch. When enabled, outputs 1-4 take up the states of the other switches. U2 is an octal latch circuit to hold those states when the oscillator is disabled.

Wow....that's great. Thanks.

 

You guys have given me plenty to work with....thank you very much.