Piezo pushbutton

fluc

Member
2008-03-28 6:35 pm
Hello everyone,

I am looking for some piezo pushbutton in Canada or the USA. The ones I found are quite expensif. About $20.00. Anyone know of a good supplier?

We are having a hard time with our door bell buttons that keep freezing. Looking for something that will resist the hard Canadian winter.

Kind Regards,
 
I_Forgot said:
The man asked for a piezo pushbutton. He didn't say what he wants to do with it.

Sorry, I thought the application as described in the original post was obvious.

I_Forgot said:
I have no idea what good it would do in the context of a doorbell but he might have some interesting idea.

Well if the igniter is wired correctly the doorbell will no longer be needed. He will know when someone is at the door when they yelp in pain.
 
fluc said:


This is a good idea. Now how do we insert a resistor inside the button?

1. Open button up with a screwdriver.
2. Replace light with resistor operating just within it's power rating.
3. Close the button back up.

Doorbells usually operate between 12 and 24 VAC. The switches often have a small lamp inside that lights up so people can find the switch when it is dark outside. The lamp connects in series between the transformer and the bell. It doesn't allow enough current to pass to ring the bell, but does allow enough to light the lamp. The button is wired in parallel with the lamp. When you push the button, you short the lamp and it goes out, the bell rings. If you replace the lamp with a resistor that dissipates 1/4 or 1/2 W it will stay warm and prevent the button from icing up. Resistor is selected based on the amount of current that will prevent the bell from ringing, and will heat up the resistor which depoends on the voltage used in your system.

Measure the voltage. Calculate resistance required to dissipate 1/4 or 1/2 W. Get that resistor and try it to make sure it doesn't ring the bell. Install it in parallel with the switch. Done.

I_F
 

fluc

Member
2008-03-28 6:35 pm
Re: Keep It Simple......

pinkmouse said:
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.

rcavictim said:
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.
 
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/ProductDetail.aspx?qs=fxxZwZgTYwBvUI7YpLJirw==

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.
 

fluc

Member
2008-03-28 6:35 pm
BrianDonegan said:
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/ProductDetail.aspx?qs=fxxZwZgTYwBvUI7YpLJirw==

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