Re: TI-H: Built in speaker


[Prev][Next][Index][Thread]

Re: TI-H: Built in speaker




Maybe an modification can be done with the use of a potentiometer. You can
change the resistance thus, change the volume of the piezo buzzer. If it
is not loud enough, maybe an addition of more volts with a battery pack.
Then you have a heavy TI.

On Fri, 12 Dec 1997, Richard Piotter wrote:

> 
> I don't know if it will fit, but "MINIATURE PIEZO BUZZER ELEMENT" 
> Catalog number 273-064 is LOUD. It costs $1.79, but it is in a 
> reverberation case that "shapes" the soundwaves comming out so they 
> sound louder. only catch is it is thicker cause of the case. It runs on 
> between 3-28 volts, and at 12 volts it creates 76 decibels. I usualy 
> cross the red and blue wires and connect those to the tip and middle 
> pins of the link port. the black wire goes to the base (closest to the 
> bottom of the calc. It's ground for those who are new to TI 
> electronics). I'm not sure, but some programs use either or even both 
> signal lines for 1-bit stereo. A small switch (DPDT) should have the two 
> center pins connected to the tip and middle pins of the link port. The 
> two pins to one side should be soldered together and the red and blue 
> wires connected to those. The black wire can connect to either the base 
> pin on the link port or the base ground (my preference). There are the 
> two large exposed surfaces of copper where the two screws connect the 
> foil cover over the back of the board. The switch fits very nicely to 
> the side of the battery case. Has to be small though. My only question 
> is whether the thick buzzer will fit? It is 15/16" diameter (almost an 
> inch) and it's 5/16" thick.
> 
> Someone should try it, cause I can't for a while.
> 
> If someone can make a 15/16" hole in the back of the case and have the 
> speaker stick out a little bit, just enough to allow the cover to slide 
> over it, then there might be enough room. also, if someone has a 
> grinder, you could probably grind the entire top off and drill a tiny 
> hole in the case. This method would allow the case to become a part of 
> the buzzer's case. Try stuff! my calc has backlight, SPinTerface, 
> Acceleration, and NO room, so If I can find the room for it, anyone else 
> can. If I can fit it into mine, I'll post it.
> 
> Much more dificult (only finding the parts, not the work) would be to 
> get a standard thin piezo element and a properly sized O-ring (like in a 
> water faucet. you can get them at a hardware store). glue the O-ring in 
> to the case somewhere where there is room. Drill a hole in the calc case 
> in the center of the O-ring. Then glue the piezo element to the O-ring. 
> You could probably drill a few holes on the side of the calc to allow 
> sound to come out better. Maybe 2 holes on each side (don't hit the 
> circuit board. The enclosed nature of the calcs case may act as a giant 
> audio resonator and make the sound come out richer. Yesterday I built a 
> speaker with an audio resonance chanel. It is AWESOME. It is a cheap 
> little 3" speaker with bass pounding out from a small opening on the 
> bottom front. I want to build two using +8" speakers. The calc case may 
> have a similar effect to the speaker I built.
> 
> You could add a tiny variable resistor to control the loudness. 1-10K is 
> fine. It HAS to be small though. make sure to keep glue out of it or 
> it's RUINED!
> 
> You could also create 2-bit sound. It isn't much for improvement, but  I 
> think it is possible. You simply need a resistor or two that reduce the 
> sound level and when combined allow the combined current through the two 
> to be close to the current from one. (the current won't combine from 
> both to make it louder. I tried.) I don't know any programs that use 2 
> bit sound though.
> 
> The sound would be something like this:
> 
> 5v |              |
>    |              |
>    |          |   |
>    |          |   |
>    |      |   |   |
>    |      |   |   |
> 0v +------+---+---+--
>      00  01  10  11
> 
> If someone wants to try it, go for it!
> 
> >
> >
> >
> >>I've done it.  Use a piezo transducer and that will not freeze your 
> >calc.
> >>Unformally called a beeper.
> >>
> >>Grant
> >
> >Great! Now can you get some (Rat Shack) part numbers and make a little 
> >picute for the switch stuff? Call me stupid, but I don't do electronics 
> >that well... the mose advanced thing I've done was slicing a wire to 
> >make a headphone jack and put tape all over it! (I wan a built in one 
> so 
> >everyone can hear it! And make it louder...)
> >
> >-Joe Martis
> >
> >______________________________________________________
> >Get Your Private, Free Email at http://www.hotmail.com
> >
> 
> 
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com
> 



References: