runningBB Arduino bell from SingleAA cell  - Page 1
Forum section: electronics / projects

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 21, 2015, 10:10:07 pm
content: I am trying to make a musical bell .Mainly because of custom melody can be programmed,so it will support tunes commonin native languages.want to power it with 2 or 1 AA cellsI 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/iYFdLJThe atmega is the MUSICAL BELLand added a 10second timer with Q3My assumptions are the transistor timer Q3 is fully off so battery drain will be nano ampereschoice of atmega8 is dueto easy availabilitybut need to make little loud enough soundwill it be enough to drive musical arduino with a buzzer ,buzzer has to be added with transistor to make loud?

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 22, 2015, 04:55:40 am
content: no one ..very good

author: miguelvp
author_rank: Super Contributor
timestamp: February 22, 2015, 05:03:00 am
content: 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.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 22, 2015, 07:23:29 am
content: thanks atleast .. for inviting , i will try to do that . seen some places the Atmega running off 3Vi 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 flapthereby we dont need to find a caseQuote from: miguelvp on February 22, 2015, 05:03:00 am

author: JohnnyBerg
author_rank: Frequent Contributor
timestamp: February 22, 2015, 09:04:12 am
content: 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

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 22, 2015, 09:48:03 am
content: Quote from: JohnnyBerg on February 22, 2015, 09:04:12 amthats a good information but the thingy is a music maker , so will the thingy pull the buzzer current which is boosted with a BJTi will tweak to keep output in approx 7V so that zener takes v little or 78L05?keeping components count lowrealized that this thingy can be a musical greeting of made in smd(i am lil old schoolmany of my designs are planned keeping in mind the simple to find parts so that people can do a build even in remote areasSomehow get an atmega shipped.. many place there is no digikey like services and getting parts from different vendorsadds to the cost )

author: Zero999
author_rank: Super Contributor
timestamp: February 22, 2015, 11:05:17 am
content: Quote from: JohnnyBerg on February 22, 2015, 09:04:12 amAdd 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.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 22, 2015, 05:45:58 pm
content: Quote from: Hero999 on February 22, 2015, 11:05:17 amThats very good one , I guess tweaking resistors of main oscillator we can keep final voltage in approx 6-7 and keeping previous circuitbut 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 bellso that we can give 1AA or 2 AA battery,due to compact size it will be placed in a dead remote casinga project that all can do without hunting for casing battery holder fitting

author: Zero999
author_rank: Super Contributor
timestamp: February 22, 2015, 07:39:58 pm
content: Quote from: dave_j_fan on February 22, 2015, 05:45:58 pmYes and to make it louder you can bridge the outputs, connect the piezo across them and feed them opposite signals.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 24, 2015, 05:41:38 am
content: MAy be tone Ac library with arduino will work

author: BlueBill
author_rank: Regular Contributor
timestamp: February 24, 2015, 05:56:54 am
content: Why not use 3xAAA batteries and avoid all the extra electronics?

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 24, 2015, 06:26:06 am
content: Quote from: BlueBill on February 24, 2015, 05:56:54 amcasefit problem ..need to hunt for 3battery holder caseand painful fiiting to another etc .1 or twin cell battery means we can fit in cheap radio or remote control caseeven it will be suitable for my other builds like a Marker case call bell and greetingAnother one is to develop 1AA solution for many of 5v only devices

author: BlueBill
author_rank: Regular Contributor
timestamp: February 24, 2015, 07:14:16 am
content: 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.

author: mrgregs
author_rank: Contributor
timestamp: February 25, 2015, 05:22:40 am
content: Quote from: BlueBill on February 24, 2015, 07:14:16 amIn fact, theATtiny43ucan run off 0.7V, as it's got a built in boost converter.

author: dave_j_fan
author_rank: Regular Contributor
timestamp: February 28, 2015, 06:08:15 pm
content: the standard melody chips take <1uAi 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 5VThere are AtTiny series that do well in 3V but many place people dont get them !