Piezo pushbutton

[fluc]

Thanks I_Forgot for the reply.

I will try it out.

Best regards,
fluc

[I_Forgot]

If the lamp (incandescent bulb) is working it will probably be warm enough to prevent icing.

I_F

[pinkmouse]

Surely it would be easier just to use a sealed microswitch, or a reed relay and a magnet in the button?

[rcavictim]

Put up a sign made from freezing tolerant materials, (paper and felt pen works) asking people to knock. It works well and uses no electricity so it is good for the environment. As a bonus it acts as a filter which keeps really stupid people who cannot read from calling your attention to the door and wasting your time!

[fluc]

Originally posted by pinkmouse
Surely it would be easier just to use a sealed microswitch, or a reed relay and a magnet in the button?

I am not sure that this would prevent the buttons from freezing. The problem arrises when it rains and then afterwards we get cold temperatures. The water accumulates and it freezes. we tried several types of buttons and none seemes to really do the job.

Originally posted by rcavictim
Put up a sign made from freezing tolerant materials, (paper and felt pen works) asking people to knock. It works well and uses no electricity so it is good for the environment. As a bonus it acts as a filter which keeps really stupid people who cannot read from calling your attention to the door and wasting your time!

This would be a good option if there was only one door. This is for a large building with 6 different doors.

[BrianDonegan]

I would not call them inexpensive, but there are many illuminated vandal proof buttons that are designed for outdoor use.

Here's the cheapest one I could find (quickly): http://www.mouser.com/Search/Product...7YpLJirw%3d%3d

It's zinc, but should work fine. You could also go with stainless steel.

To power the LED, add a diode and resistor.

Good enough for an outdoor ATM.

[dnsey]

Fit the switch inside the house, and run a PTFE pushrod through the door/frame to operate it.

[fluc]

Originally posted by BrianDonegan
I would not call them inexpensive, but there are many illuminated vandal proof buttons that are designed for outdoor use.

Here's the cheapest one I could find (quickly): http://www.mouser.com/Search/Product...7YpLJirw%3d%3d

It's zinc, but should work fine. You could also go with stainless steel.

To power the LED, add a diode and resistor.

Good enough for an outdoor ATM.

Thanks BrianDonegan. I am looking into it.

I would like to thank everyone else for their replies. I appreciate all the info and ideas I got. I will let you know how we make out.

Kind regards,
fluc