Need circuit designed and built

[MrLister]

Hello,<p>I am in the process of designing a new product, but I don't have an electronic background.<p>I have a great idea of for a product, but I need to find out if the hardware for the circuit can be built in a cost effective manner.<p>A brief overview of what I am looking for is this:
A receiving unit that is less than .5 inches square and is capable of receiving at least two different frequencies from a remote transmitter.<p>I would be interested in hearing all opinions and if you can make such hardware and approximately how much something like that would cost.<p>
Thank you very much,
Mike
[email protected]

[hlreed]

Mike,
You might like to look at model airplane radio control units. Most model airplane units can only see one frequency, but you might use two of them.
Don't know much about radio.

[billdar]

Just two quick questions...<p>What is the range of operation?<p> -and-<p>Why do you need 2 frequencies? could it be 2 channels on one frequency, or seperately encoded data?

[russlk]

What is the RF frequency, and does the antenna have to be within the .5 sq. in.?

[jollyrgr]

More information please. Does it have to receive two RF frequencies? Or do you want to transmit one RF signal and two audio tones so that you can control two outputs.<p>What kind of power source are you running this device off of? Twelve volt car battery, single AAA battery, or a watch battery? What will the transmitter strength be? Are we talking garage door opener transmitter, toy remote control ("Fisher Price" type), big boy remote controls (RC aircraft, gas powered cars & boats), CB/Ham radio, pager towers?<p>Please provide a couple more details.<p>But to get you started, take a look at these pages:<p>http://www.rentron.com/RF-Remote.htm<p>And in the UK<p>http://www.rfsolutions.co.uk/<p>These show a couple of short range units that can run off nine volts and three volts. In the case of the UK unit, these are very small SMT devices and are ready made. Although these are a bit bigger than what you are looking to use, they are a start to at least look at.<p>[ July 24, 2002: Message edited by: Jolly Roger ]</p>

[MrLister]

Sorry I neglected to include some of the pertinant details... but I truly don't know much about electronics... I am a software engineer.<p>So here goes:<p>Model airplane receivers are way too big.<p>the receiver MUST be .5 inches square or less
(preferably less)<p>The height of the receiver must be .735 inches or less INCLUDING power source.
( again smaller is better )<p>I really don't understand the channel versus frequency issue... The first version will only have to distinguish between 2 different signals.
The final "finished" receiver will have to be able to distinguish a TOTAL of 5 different "signals" - Whether this can be on a single frequency with mutliple channels or will require different frequencies... that is why I posted here.<p>As to the power that will be required - I assume that it will depend upon how much the receiver will be required to do - again for someone who knows electronics.<p>The range I am looking for the receiver to "acknowledge" a received signal a MAXIMUM of 50 feet line of sight, or through a single normal household wall. ( in the same house )<p>The receiver and all accessories to make the receiver work must be able to fit within a .5 inch X .5 inch X .375 inch cube.<p>
The transmitter can be larger ( like a garage door opener )

[russlk]

OK, lets say we have a receiver operating at 144Mhz carrier with 2 to 5 subcarriers which can be AM or FM modulated. What is the nature of the modulation? Is it audio, video, or logic levels? If logic levels, what is the data rate? There will be 2 to 5 outputs, one for each signal. What will you do with the output? Does it have to drive a 50 ohm cable, a high impedance recorder, what?

[billdar]

You might be able to squeeze the electronics into that cube, but a power supply and antenna probably won't fit. I seem to be a sales person for linx, but try them www.linxtechnologies.com for a 2.4GHz chip Rx/Tx IC's. Then check out Altera/Xilinx for small surface mount plds to make a simple ASM sequence detector. For batterys use a single (or double) 3.3V watch/hearing aid battery. Antennas you can get a coil type that is very small that are used in keyless entry type devices. In all, I think you may need to relax the size constraints.

[MrLister]

Russ, to answer your questions... I don't know. <p>What I do know is the 2 to 5 different signals that the receiver will detect, need to start a LED light flashing and/or make a small beeper beep. They also need to switch internal circuitry on the receiver. The receiver will not "drive" anything else other than those things.<p>Unfortunately the size is a physical constraint that can NOT be altered.<p>Mike

[billdar]

I got one last question... how many of these are you making and what is your budget?<p>If the answer is many, and the start up capital is there, I would get in contact with an ASIC or Mixed signal IC design house. They can integrated everything you need onto a single IC, and package it to meet your requirements. They can even design system to run at a low voltage. The company I work for vested $10,000 on a prototype Mixed IC and recieved 70 chips. <p>Good news is is that 90% of the money is design and retooling, so susequent chips will run about $.25 per 1000. You might get a better deal working with an overseas company.<p>As far as I know (and my knowledge is limited) you will have much difficulty finding comercial products to meet your specs. Good luck

[MrLister]

BillDar,<p>That is just what I wanted to hear. <p>To answer your questions, yes, I require lots of these... and I do have the startup capital.<p>Where can I find out about ASIC and/or Mixed Signal IC houses?<p>Are you an electronic engineer?
( or someone capable of designing circuits? )<p>Thank you for your help.
Mike

[billdar]

Im both... I design high-speed digital ASICs and the systems they go in. I could design all but the analog communications stuff.<p>If you got the cash, I would stick to stateside companies. It'l cost more, but you'll get better support. <p>They are usually call assembly houses, industrial fabrication, or wafer processors. I only know three companies by name, but they are who my current company deals with and don't have authorization to disclose the info.<p>I can say this, do a search on google for the above and you'll find your way.

[MrLister]

Billdar,<p>I assume the analog communications stuff you refer to is on the receiver. Who would be capable of designing that - the "assembly houses" you refer to ?

[bwts]

I would have thought so receiving + transmitting circuitry is well established (tinhk moblie phones)<p>B

[JdOwNj]

Thts pretty darn small...