Looking For a senative tiny MIC pickup for room

[directcurrent]

Hello every one. I have a project that I badly need;
***My MOM/DAD both have Alzheimer's, it hard for me to stay in the room with them all the time. So I need a super senative MIC that very tiny and can transmit to a receiver connected to a DVD or VCR which is my shop some 100 ft. away so I can listen in on them and do my work in the shop. I want to install several of them thru-out the house so I make sure they are not fighting or hurt and I can get to them.
***I have no idea where to begin this project nor what I need to get it done. Can anyone of you folks couch me or get some idea what I need -before I pull my hair out (chucklechuckle!!!!!!) Please Please.

[Externet]

I do not know what 'senative tiny' means.
Baby monitors are your most convenient gadget to buy, they transmit sound in a baby's room to parents' room on a talkie-similar gadgets, and should be widely available at many stores.
Fancier ones have video too.
Miguel

[directcurrent]

Hello Externet, Just got Thur reading your response on the other thread I wrote, Thanks.
*****When I wrote tiny, I mean the size of a half dollar but know larger than a pack of cigarettes. I have the means of working on SMT's if need be, I have one of them old cameras and TV monitors to do small parts work. I tried one of them Baby monitors, it did not work to well specially after mom hit things with her walking Cain. But then we had to replace TV sets, VCR's, and telephones too and my computer. "OUT-CH"!!! That is why I need to monitor them. Thought about buying one of them small security cam the size of a quarter and just use the audio part of it, but have not found one that size that has both audio and video, that probable work well for me. I hate to be a snoop, but in this case I think you understand why. I wish I could found a schematic on something like that. O Ua.. in this area electronics is scares as hens teeth around here.

[CeaSaR]

How about a small FM transmitter in the standard FM range (~88 - 108 MHz)? There are scads of schematics
out there on the web. Many can be built for $10 - $20 and have enough range with a slightly longer antenna.
You'd have to make sure that it doesn't reach much farther than you need so as not to get in trouble with
the FCC. You could even have several on different (unused) stations to keep track of what room they are in.
That way you could keep easy track of them in the house. Just have enough radios on so you can hear each
transmitter while in the workshop.

CeaSaR

[directcurrent]

Now thats an idea, you got an idea of any particular website for something like that. Biggest room is only 12 X 15 and I only need four rooms, I have to lock my room up and the range to the Radio is maybe 20 ft. Maybe I can put like a meter or a light or different tone bell to go off when there is voice noise in a room and I will know which room there in or has to said have four radios maybe tied to the same out speaker, if they are isolated there should not be a problem.
Well got to go another bad storm is coming. God Bless DC.

[CeaSaR]

DC,

I haven't forgotten about your request. I had found some sites earlier, but ran out of
time before I could post. I'll try to get to them tomorrow sometime.

BTW, I found out you have quite a few open frequencies to choose from in your area.
I'll post the link to that site tomorrow as well.

As for what I had pictured in my mind, you could have a "White Board" set up on your
shop wall with a layout of the house and a speaker in each of those "rooms" attached
to the corresponding receiver. You could attach a comparator to the positive side of
each speaker to light an LED when a certain threshold (volume) is reached, thereby
giving a visual to which room they are loudest. If you were to see 2 or more LED's light
up, you would know to pay attention and check things out. You could even keep track
of them by audio if the "Board" is big enough to achieve decent separation. As a bonus,
you could have a 4-pole switch to keep the speakers turned off, allowing only the LED's
to signal you - for those times when you need peace and quiet.

I would put the the transmitters into a decorative enclosure with an electrical cord to
keep plugged into the wall. I would tell them it is an important piece of safety equipment
that is not to be touched so they don't move or destroy them. Bonus there is that you can
have a very small power supply built in - if you wish.

Just my idea. Maybe there is something there you could use.

CeaSaR

[directcurrent]

I know what you mean by time, between taking care of my folks, doing work around the house and what I can do around the shop, does not leave much time to have a personnel life. I am just now having my dinner. I am disabled myself due to job work stress and dibeties. Some one keep stilling my remote to my prosthetic leg and I have to chase it down on the TSF forum.

CeaSaR, you have some very good ideas , my ears are open!!!! I may do all of them. I might use a clock case and do a bit of mood to it to put the mic and transmitter in it, that would give me the room for the antenna. I want have any problem with a place for the receiver/ switches/ and stuff. I'll be waiting for the added info from you.

BTW, I kindof got to laughing with your name, please forgive, I was thinking of one of my Japanese monsters, that I have seen, when I saw it>> King CeaSaR << don't worry he was a good guy. Them monster movies use to make me laugh, get the stress off.

Thanks for the help. Blessing of all kinds DC

[CeaSaR]

Ok, here are some sites. First are the schematics:

aaroncake.net
electronics-project-design.com
rf-kits.com

All found through this search:
search

Least expensive kit I found:
Carl's Kits

Vacant radio frequency link I found at CCrane - look near the bottom of the page:
CCrane Xmitter w/vacancy locator

Direct link to the locator:
Locator

The search where I found them:
search

While the schematics tell you how to build them, I think that a kit will help ensure success,
and that is what you really want for this endeavor. My rough idea of the board looks
something like this:



All you need from the radios is access to the speaker in each. Extend the wires and connect
to a small (2"-3") speaker on the board. Put 1 pole of a 4-pole switch in line with the positive
side of each speaker, to give you peace when you need it. On the positive side of each speaker,
before, the switch, hook up a comparator and adjust so the LED lights when conversation is present.
You may need to play with the adjustment to come to a compromise between when the speakers
are on and when they are off.

For the transmitters, the version shown at Carl's Kits runs off of 3 volts. You can either build/buy
a very small power supply or use D cells for long run times, maybe even parallel several sets to
achieve even longer run times.

Don't forget to check the free station frequencies and verify them. Also, take a portable radio
outside and make sure each transmitter doesn't go more than 300 feet or interfere with any
other frequency.

CeaSaR

[directcurrent]

Hay CeaSar, this is great, I am mighty greatful to you, thanks. It was very much needed today, it would have been a life saver.
I must be following your logic. I sketch a panel out today and it was not to far off from yours. I have eneff material for the panel stuff to put it together or a good porsion of it. I will have to wait to the first of the month to get the kits. This month full of bills. Your are wize, kits would save me much time. O BTW one of the naighbors here use to have lots of yard sales and happen to have just what I needed to encase to transmitters and mic stuff for free. And a ideal case for the panel and stuff for the shop. I will check back with you in a few days. I have found a hardshell case to mount my computer in and lock it to keep it from damage. God Bless CeaSar. >>>>>>DC.

[directcurrent]

sorrow for the double post;

CeaSaR>> I see what you mean on the transmitter and I agree. The saleman at Carl's is going to help me out a bit, can say what but it worth the deal. I should be getting the number transmitter I need by the five of next month. And I foud something else I could us two at carl's Thanks.

I am going to look at the other places so I can place them in my folder for good info and if I need a backup plan to.

[CeaSaR]

Gentlemen of the (Nuts and Volts) Board,

I would like some help with directcurrent's request and my possible solution.

Refer to my second post above where I describe a possible layout of a "whiteboard" and
suggest the possibility of using a comparator to light an LED when a desired level of audio
is reached on the speaker line. I envision using a (variable) voltage divider (via potentiometer,
for adjustment) to feed either a comparator, an op-amp or a 555 timer to light the LED. What
are your thoughts on this? Does anyone have an idea how to efficiently and (most importantly)
inexpensively implement something like this?

Ideally, it should be driven from the positive side of the speaker (before any "mute" or "quiet"
switch) and able to operate when the speaker is not connected (mute or quiet/disconnected
from ground). There should be 4 individual units so as to monitor each "channel".

Any help or pointers would be greatly appreciated.

Thanks,
CeaSaR

[CeaSaR]

Second idea here,

Maybe he could use a simplistic LED "VU" meter, maybe a 3 step with green/yellow/red
corresponding to 3 different volume levels, ie. "Low, Medium and High" to give a rough
idea of the level at a glance. Something like this might be implemented via an op-amp
(741??) AC coupled to the positive of the speaker feeding a resistance ladder with the
appropriate LED at each junction of the ladder.

Thoughts anyone?

CeaSaR

[directcurrent]

I read you re ponce. The comparator and 555 I have a tube of them left from long ago project at a plant that close down. I have some various sizes of Leds to, Resistors I will have to buy at the electronic store here or get them from Jenson or something. fuses and power supplies A plenty. experimental PC board I have a few and sheet metal, wood and plenty of tools. I am well versed in micro soldering from a plant I worked at.

[sofaspud]

I think the display portion could be simplified by using 4 LM3914 ICs. Perhaps incorporating a
"level red" buzzer alarm and/or strobe flash to make monitoring the system less of a chore.

[directcurrent]

The sprobe would be idea, that way I want have to look away from the drill press or electric saws, that could get messey. I am installing a phone in the shop to so I can call into the house as an inner-com system. That is after I get this completed. I found the phone I want inside the house but as they say ! project at a time for them.

Ua... LM3914 I don't have any but I know were I can get some, talk about luck, a man at the waffle house today say he was retiring to a home and he was wanting to get rid of all his electronics/equipment and stuff out of the store house, if I'd pick it up by next week for free. Weeeee!!!!!!!! Got my next door neightbor with a simi tuck that is going to help me get anything that is not nail down. never look a gift horse in the mouth. He even has storage boxes and racks to go with it. WOW