Boring old switches

Capacitive touch switch?

Oh -- and it's gotta be a traditional switch. This is to work with existing equipment, not something that can be done with circuitry.

Just a boring old switch -- of the right kind.

There used to be these Arrow Hart and Hegemann (sp??) switches that had a spring-toggle mechanism inside, and needed at least a pound of force to activate them. Standard 3/8" and 1/2" threaded panel bushing. I doubt AH&H are still around, but there must be something made for industrial control panels that requires a firm push to activate.

Jon

I've used these many times. Good stuff.

mini Toggle with boot?

Cheers

Generally if you want to make sure something doesn't go off accidentally, but want push button speed, you use two push buttons. Separate them so it takes two hands to initiate the action. No scheme is foolproof, but the odds of two switches failing at the same time is less likely than one failing.

You see this on old missile launch stations.

But if you need to push both, the chance of a failure that prevents operation is double.

You need to weight the consequences of the operation. If you are starting nuclear war, maybe requiring two pushes is a good idea. If you are operating a press, two switches in the right places will assure there are not fingers to get chopped off.

Consider it the hardware equivalent of perhaps the software message "Are you sure you want to delete all files in the directory?"

Safety schemes can backfire. The classic case is the brake sensor switch that locks out the transmission. Do you want to prevent running over a child accidentally but risk stranding a motorist? That lockout fails quite often.

Nothing is perfect. It is an analog world. You take your chances.

Tim, Take a close look at the pushbutton switch offerings from OTTO Controls. We used certain ones of these on industrial joystick handles for push control buttons when I worked at ITT's Controls division. Very nice buttons.

These may be the most cost effective for your application:

This is for control line precision aerobatic ships, some of which can be pretty seriously super-zoot, with hundreds of dollars of material, and hundreds of hours of time invested. Going for a $10 switch on one of these is worth it to save you from a crash, or even just a lost contest.

Here's some eye candy to explain the seriousness of this pursuit. The hand flying that plane is one of the pair of hands that built and finished it. He does not want the motor to cut out when he is inverted or flying overhead:

Well, cool stuff. I'm sure you would like the quality and user feel of the OTTO pb switches. They worked extremely well on the heads of control stick handles for industrial machines like joysticks for earth moving machines and lift type machines.

...

Bank teller alarm trips are two buttons back to back. You must squeeze both for a trip. If you hit one only, it's not an alarm but does start the cameras. Tellers are trained to so so if/when they see someone suspicious potentially casing the place.

Oldest daughter graduated from Scripps College (Claremont) and hubby from Claremont McKenna in 1984 (graduated one day, married the next on the lawn at Scripps).

While he attended USD Law School she worked as a branch manager for B of A.

One day they were robbed, my daughter pushed all the right buttons and handed the perp the explosive-dye bundle of money.

Perp runs out the door into hands of the police, but the money pack didn't blow. When the cops grabbed him he dropped the pack.

Little old lady walking into bank picks up the pack and carried it back into the bank, where it blew... ink all over her ;-) ...Jim Thompson

Not all banks use the same setup. Some use a "bait drawer" (a stack of marked $20s). If the bait is removed the alarms automatically trip. Some have sensors in the "bait" that trip the alarms when removed from the building. They even have GPS packets (in hollowed out bill packs) that'll track the perp to where he lives.