"Don Y" wrote in message ...

On 1/16/2016 10:24 PM, Tony944 wrote:
I have replace more then on push button but I never came across door push
button with diode in inside, if there is diode it would be inside bell
enclosure itself.

It depends on the functionality provided by the diode.

A diode *shunting* the button allows (some) power to flow
through the button even when it is not pressed (assuming
typical AC drive for the doorbell circuit).

I need some explanation, you are saying that chimes/bells
have constant power at all times through diode when button
is not press and full power when button is press, I would love to see that
I am not saying that is not possible but I would like to see that.

A simple 1 or 2 tone "bell" only needs -- and receives! -- power
while the button is pressed. The button completes the circuit to
the bell WHILE the button is pressed. As soon as the button is
released, the circuit is broken.

For a 1 tone bell, the chime/buzzer sounds while the button
is pressed.

For a 2 tone bell (ding.... DONG), the first tone is the result of
a solenoid pulling a striker to hit the first (DING) chime. The
second tone is a result of the striker being released and returning,
via a spring driven mechanism (to strike the DONG on the "back end"
of the striker).

For more complex mechanisms (and some electronic doorbells), power
needs to continue to flow through the button even AFTER it has
been released -- the bell mechanism can't "store" the electricity
that it needs. The diode allows "half" of the electricity to
flow all the time. This is enough for the mechanism to CONTINUE
operating.

The mechanism won't *start* its cycle/operation until it "sees"
the "full" electricity (which is only present when the diode
is SHORTED by the switch -- thereby allowing ALL the electricity
to flow to the bell mechanism).

The position of the bell mechanism, electrically, only allows it
to get power when the button is closed (or, bridged by that diode).
You have to route the wiring differently if you want power to
come to the bell unit all the time -- feeding the switch FROM
the bell unit (instead of feeding them in series with each other).

So, a diode in the bell unit in a traditionally wired circuit
can only *discard* half of the electricity presented to it.
If the (non-diode) button is "open" (not pressed), then there
is no electricity to discard; no electricity to operate!