Cool push button switch

[RandyT0001]

So let me get this straight. This push button illuminates itself for a brief time while it completes the circuit as your opaque thumb depresses it? Why?
:confused2:

 

[luke strawwalker]

So let me get this straight. This push button illuminates itself for a brief time while it completes the circuit as your opaque thumb depresses it? Why?
:confused2:

Yeah, is that what it does?? I thought I was just reading it wrong! :caffeine:

Would be rather pointless if that's all it does... who's going to watch their finger pressing the button when a ROCKET IS LIFTING OFF?? :blush::confused2:

Now, if you could wire it so the "launch" button lights up when you have continuity and insert the key... THAT would be way cool!

Later! OL JR

 

[Bazookadale]

:

Now, if you could wire it so the "launch" button lights up when you have continuity and insert the key... THAT would be way cool!
Later! OL JR

That is what I thought he meant and I believe it could be wired that way

 

[Trident]

So let me get this straight. This push button illuminates itself for a brief time while it completes the circuit as your opaque thumb depresses it? Why?
:confused2:

The third little icon on the website shows the schematic of that push button switch. The LED has its own contacts -- it is not tied into the switch circuit, so it can be wired just like any other lamp you would put into a launch controller.

Also, the switch is DPDT, two separate circuits, with Normally Open, and Normally Closed contacts. For anyone wanting a little more inforamtion on what that actually buys you, do a Wiki on "DPDT switch". A DPDT switch is more than needed for a launch controller, but good to have options on switches like this for other applications. For a launch button, you would use either switch 1 or 2 -- let's just say to use switch 1. Do your wiring to the Common terminal 1, and the Normally Open terminal 1. That means the igniter would be fired when you push the button, to "close" the circuit -- it is "normally open". (The Normally Closed terminal keeps that circuit thru the Common terminal "closed" when the switch is not pressed, and "opens" the circuit when you press the button.)

 

[MarkII]

Ok. I'm about overdue for another dumb electronics question so here is one I don't have and handle on yet.

I understand the purpose of the limiting resistor and why they are needed.
How are they generally mounted"

I mean do you solder/crimp your wire to one end of the resistor and then lead another wire from the other end to the LED?

Do you make a little circuit board with resistors on them and terminals at either end so that the wiring can be attached?

Do you just toss the resistor into the enclosure and hope that it will accidently short across the right points?

I really am this clueless when electrons start moving around.

Great question and great answers. Your third scenario would have been my guess. Aren't all electronic devices built that way?

 

[JAL3]

Aren't all electronic devices built that way?

I don't know about "all" but its a fairly common practice with me.:confused2:

 

[RimfireJim]

Forgive my ignorance.

Resistor Array? I saw the pictures. They jsut don't mean anything to me.

It is a package containing 8 (or some other quantity) of resistors. I think they may be all of the same value, but not sure about that. It's not what you originally asked about, though - it's not a circuit board. In fact, they are designed to go onto a circuit board.

Needing a resistor here or there, whether for current-limiting an LED or pulling an input up or down, is pretty common in industrial controls. Typically, one lead of the resistor is inserted into a terminal block which is just one of many on a panel, and the other lead is soldered and shrink-tubed to the wire lead for the circuit. A 1/2W resistor is so small that it doesn't have enough mass to require any more support than that.

 

[Bone Daddy]

Hey JAL3, printed circuit boards (pcbs) are used in just about everything these days because machines do all the work. Google pick and place machines and wave soldering to get an idea of what robots can do. Also just about everything is going to surface mount devices which require printed circuit boards.

You don't see printed circuit boards (pcb) in our simple launch controller circuits because they have no advantage - and many disadvantages - over point to point wiring.

Point to point is the most flexible as far as panel design is concerned. You can drill a hole anywhere in your project box and mount a switch or an LED. With a circuit board, you have to worry about aligning each and every LED and switch mounted to the board with a specific hole in the project box. Not that easy to do.

I'm working on a launch controller that is based on two microcontrollers, one in a relay box at the launch pad and the other in a launch control box. It will be a mix of point to point wiring and pcbs. Here's what the pcb for armed/continuity circuit looks like. It uses both through hole and smd resistors. I etched and drilled it at home.

The other pics are of a mock up the front panel of the launch control box.
Note that the switches are all point to point wired and that this daughter board will be connected to the main board with point to point wiring. The prototype (wow, that sounds technical) is for 2 pads, but the goal is 4. The microcontroller I'm using could easily handle 8 or more pads.

I'll start a thread on this sometime. It's really an amalgamation of two hobbies: robots and rockets. The goal is to eliminate wires between the control table and the launch pad and to make it impossible for a high school kid to accidentally launch a rocket before it's time has come.

 

[cwilliams]

Bone Daddy -

Does the abort switch destroy the launch vehicle in case of a cato?





...because it would be cool if it did. Just sayin!




Really, I am curious as to what it does. You have an LCD there. Possibly a countdown timer?

 

[Bone Daddy]

Actually, it aborts the future growth of the rocketteer that caused the situation requiring an abort. It also wirelessly send condolences to their parents.

 

[cwilliams]

:roll:

 

[Bone Daddy]

Here's the serious part.

The abort switch resets the active launch pad to an unarmed state. The display will flash AA indicating the launch system is in abort mode. There will be a series of steps that must be taken before it can be rearmed. There will be a set of parameters that indicate when the launch should be aborted.

It has a built in automatic 10 second countdown.

Pushing the launch button starts the countdown. After it reaches zero, the launch switch must be pressed again. If not pressed within 5 secs, it automatically enters abort mode.

This is all very preliminary. The goal is to have the students follow a series of checklists with the goal to emphasize how following procedures reduces the risk of an accident.

This is what abort mode looks like.

AA indicates abort mode.

Pad 1 has continuity, not armed (continuity LED is green, armed is red)

Pad2 has no continuity and is not armed (both LEDs are red)

 

[cwilliams]

Very cool! It's not something I've personally seen on a launch controller before and just had to ask. How old are the fliers that are going to be using this system?

 

[Bone Daddy]

High School.

 

[RocketsNorth]

Now this is cool and looks far better than a jack..
https://www.thecustomsabershop.com/Power-jack-kill-plug-P242.aspx

 

[cwilliams]

Now this is cool and looks far better than a jack..
https://www.thecustomsabershop.com/Power-jack-kill-plug-P242.aspx

I like it, but I wouldn't want to lose it for that price. 1/8" jacks are more readily available.

My solution as seen in my photo -