Re: TI-H: Built in speaker

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

Re: TI-H: Built in speaker


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
Follow-Ups: