Hi all,

I appreciate this is a design rather than repair question but I
appreciate there are some very skilled people here. ;-)

Scenario. I have a wired bellpush on the front door (frame) that runs
to a battery 'Ding-dong' type solenoid chime further back in the
house, the idea being that 'we' can hear it anywhere in the house (we
can) and also in the back garden if we are lucky (we also sometimes
can).

The 'problem' is that you can't generally hear it outside the DG front
door and so couriers often ring the bell *and* repeatedly bang on the
glass door or flap the letterbox flap, sometimes winding the dog up
thinking it's an aggressor. ;-)

So, I was just wondering ... if I had some sort of small
electro-mechanical buzzer (possibly to also give physical feedback),
just inside the front door (on the inside door frame, directly behind
the bell push for best feedback and easy wiring) that you could hear
from the outside, that might give anyone on the outside some level of
positive feedback that the bell had worked (hopefully anyway)?

So, I am limited to 6V DC via the 4 x C cells (currently Ni-Mh's so
only 4.8V) and don't want to add any real parasitic drain, especially
if I go back to alkaline cells to get the full 6V.

So I was thinking (but am no electronics design engineer) of some form
of diode fed - series resistance cap that could be charged by the 6V
supply seen at the back of the bell push that could then be discharged
via a low voltage buzzer when the button is pressed (even if only once
and for ~1s) ... and would then reset ready for another press say in
30 seconds time (given the original doorbell will continue to work as
normal etc).

Things I believe are relevant ... you would need a cap big enough to
provide as good a quality level of power long enough to give a
significant 'buzz' to be heard.

The charging resistance would need to be low enough to not cause the
bell to hang on the 'Ding', once the button was released (the chime
solenoid just returns under spring power when no current flows but
might be 'held' by a much lower current (so no proper 'dong').

I didn't know if the buzzer trigger could / should be done by a self
latching circuit of some sort or if one should use a zener to manage
the voltage allowing a better release action?

I am aware of all the other options like using a mains transformer or
wireless repeater / converters, I was really only interested in seeing
if such a direct repeater could be practical? ;-)

Cheers, T i m

p.s. Yesterday I successfully repaired one of those plug in wirelessly
charged PIR / power cut type torch / lights. It was a resistor that
burns out in the 240V base and is replaced (sometimes along with a
transistor and cap) and normally get's them working again.
Unfortunately the Lithium (14430) battery in the torch part had gone
very flat (sub 1V) so I have a replacement on the way.