runningBB Arduino bell from SingleAA cell

[dave_j_fan]

I am trying to make a musical bell .
Mainly because of custom melody can be programmed,so it will support tunes common
in native languages  .
want to power it with 2 or 1 AA cells 
I picked a simple transistor voltage booster (avoiding ICs)


without the zener the circuit gives 21V from 1.5V AA cell (inductor 470uH)
with zener 5V  i should be able to drive a ATmega8 on a EDUINO (cloned barebone arduino)
http://goo.gl/iYFdLJ

The atmega is the MUSICAL BELL

and added a 10second timer with Q3
My assumptions are the transistor timer Q3 is fully off so battery drain will be nano amperes
 
choice of atmega8 is dueto easy availability
but need to make little loud enough sound

will it be enough to drive musical arduino with a buzzer ,buzzer has to be added with transistor to make loud?

[dave_j_fan]

no one ..very good 

[miguelvp]

Enter it in the 1K microcontroller contest? 

https://www.eevblog.com/forum/contests/1k-microcontroller-contest/

Or at least give it time for people that would be interested in this, it's kind of a niche thing and you can't expect everyone to be excited about it.

[dave_j_fan]

thanks atleast .. for inviting , i will try to do that . seen some places the Atmega running off 3V 
i may think of 2cell sourceto get 3V

- due to compact size it will fit into a remote control case that has the much needed  battery holder with a nice flap
 thereby we dont need to find a case
 

Enter it in the 1K microcontroller contest? 

https://www.eevblog.com/forum/contests/1k-microcontroller-contest/

Or at least give it time for people that would be interested in this, it's kind of a niche thing and you can't expect everyone to be excited about it.

[JohnnyBerg]

The oscillator you have made is known as a "relaxation oscillator".

I think Dave did a video on that (the free energy bullshit). The oscillator can easy power a ATMEGA328 for a long time.

I even think that most of the power goes into the zener diode. If you think of something clever for that, it will last even longer 

[dave_j_fan]

The oscillator you have made is known as a "relaxation oscillator".

I think Dave did a video on that (the free energy bullshit). The oscillator can easy power a ATMEGA328 for a long time.

I even think that most of the power goes into the zener diode. If you think of something clever for that, it will last even longer 

thats a good information but the thingy is a music maker , so will the thingy pull the buzzer current  which is boosted with a BJT
i will tweak to keep output in approx 7V so that zener takes v little or 78L05?
keeping components count low 

realized that this thingy can be a musical greeting of made in smd
(i am  lil old school
many of my designs are planned keeping in mind the simple to find parts so that people can do a build even in remote areas
Somehow get an atmega shipped.. many place there is no digikey like services and getting parts from different vendors
adds to the cost )

[Zero999]

The oscillator you have made is known as a "relaxation oscillator".

I think Dave did a video on that (the free energy bullshit). The oscillator can easy power a ATMEGA328 for a long time.

I even think that most of the power goes into the zener diode. If you think of something clever for that, it will last even longer 

Add another transistor to pull Q1 low when the output voltage is too high? If the zener isn't changed, the voltage will increase slightly (5.6 to 5.7V) but it's unlikely to be a problem, otherwise use a lower voltage zener.

[dave_j_fan]

The oscillator you have made is known as a "relaxation oscillator".

I think Dave did a video on that (the free energy bullshit). The oscillator can easy power a ATMEGA328 for a long time.

I even think that most of the power goes into the zener diode. If you think of something clever for that, it will last even longer 

Add another transistor to pull Q1 low when the output voltage is too high? If the zener isn't changed, the voltage will increase slightly (5.6 to 5.7V) but it's unlikely to be a problem, otherwise use a lower voltage zener.

Thats very good one , I guess tweaking resistors of main oscillator we can keep final voltage in approx 6-7 and keeping previous circuit
but the extra transistor is a prettier choice (with varying loads ) .

What about driving the PIEZO and ATMEGA (this is 25or less mA )well with this, can it deliver the current ?

 Quick explanation to the new readers :
 We are trying a BJT booster to drive ATMAG8 based musical bell
 so that we can give 1AA or 2 AA battery,due to compact size it will be placed in a dead remote casing
 a project that all can do without hunting for casing battery holder fitting 

[Zero999]

What about driving the PIEZO and ATMEGA (this is 25or less mA )well with this, can it deliver the current ?

Yes and to make it louder you can bridge the outputs, connect the piezo across them and feed them opposite signals.

[dave_j_fan]

MAy be tone Ac library with arduino will work

[BlueBill]

Why not use 3xAAA batteries and avoid all the extra electronics?

[dave_j_fan]

Why not use 3xAAA batteries and avoid all the extra electronics?

casefit problem ..need to hunt for 3battery holder case
and painful fiiting to another etc .
1 or twin cell battery means we can fit in cheap radio or remote control case

even it will be suitable for my other builds like a Marker case call bell and greeting

Another one is to develop 1AA solution for many of 5v only devices

[BlueBill]

If size is an issue consider a small MPU that'll run off 3V or less. Some Arduino's, ATTiny or PICs can be run from 3V. Seems like your bell doesn't need much I/O. Most MCUs can sleep and draw only µA.

[mrgregs]

If size is an issue consider a small MPU that'll run off 3V or less. Some Arduino's, ATTiny or PICs can be run from 3V. Seems like your bell doesn't need much I/O. Most MCUs can sleep and draw only µA.

In fact, the ATtiny43u can run off 0.7V, as it's got a built in boost converter.

[dave_j_fan]

the standard melody chips take <1uA
i made our bell to go nanoAmps !

There are some hacks for getting the  atmega to to do work @3v  like 8Mhz clock etc  ,
For now keeping mine at 5V

There are AtTiny series that do well in 3V but many place people dont get them !