Jump to content
Mr.RC-Cam

Maxim's Loss-of-Video-Sync Alarm IC

Recommended Posts

It's not a bad idea, I'd be interested.

Well, like I said, I know a thing or two about running a successful business, and while I am not as electronically advanced as some here, I can at least understand what everyone is saying and follow along.

Who else would be interested? Of course, a company like this would not break any sales records, but it would be interesting to see what kind of other products we could come up with like receivers/esc's/etc.

Share this post


Link to post
Share on other sites

I would be interested! I am no electronics whiz either, but I have a quick and inquisitive mind and love to learn! And I know my way around a circuit board and a soldering iron and a dremel and all that(Have been heavily involved in the RC hobby for sixteen years) I also love to write and am currently working on publishing some work, so I could handle that aspect of a business...

Share this post


Link to post
Share on other sites

I think the market outhere is for the ones that are introducing to this new hobby. Our web site experience is that most of them want plug n play products with a good reputation. They are also quite experienced in r/c airplanes probably more than most of us. Also it seems to be important the post selling service, most of the products out there doesn´t offer at all.

Share this post


Link to post
Share on other sites

What I see happening is that people on this forum building a component or two and sell it at costs of parts involved. It's fine as a hobby but I don't think it's a good approach for commercial enterprise.

Somebody needs to have a vision on what's going to sell, how much money can be made and some data to back it up, i.e. have a business plan. From that point on a company can be formed and I am sure there is enough technical expertise between people here. If somebody has the plan - let's hear it, or parts of it. Otherwise, why bother?

Share this post


Link to post
Share on other sites
What I see happening is that people on this forum building a component or two and sell it at costs of parts involved. It's fine as a hobby but I don't think it's a good approach for commercial enterprise.

Somebody needs to have a vision on what's going to sell, how much money can be made and some data to back it up, i.e. have a business plan. From that point on a company can be formed and I am sure there is enough technical expertise between people here. If somebody has the plan - let's hear it, or parts of it. Otherwise, why bother?

I'll draft up a business plan, just give me a week or two.

EDIT* Actually, I'll do a marketing plan first. It's the correct item to do first.

Edited by eickst

Share this post


Link to post
Share on other sites
I'll do a marketing plan first.

Great, i'd love to read it if available.

We should take it to another thread. This one is about video diversity box by Mr. RC-CAM, sorry for deflection.

Share this post


Link to post
Share on other sites

mr. rc-cam

when are you planning on releasing your diversity receiver? $200 sounds like a right price for all-in-one dual receiver that will be cleaning up video feeds... BW's $350 version is a bit expensive for my taste.

Share this post


Link to post
Share on other sites
when are you planning on releasing your diversity receiver?

It is really hard to say. I am currently at the due diligence stage. So, there is much to be done.

Share this post


Link to post
Share on other sites

Mr.RC-Cam, have you had a chance to test the MAX7461 yet ?

I'm torn between this chip and my PIC/1881 solution.

Terry

Share this post


Link to post
Share on other sites
... have you had a chance to test the MAX7461 yet ?

Not yet. I just ordered the project's custom PCB yesterday. I won't have it for three weeks or more.

I'm torn between this chip and my PIC/1881 solution.

The LM1881 is a safe bet. In my case, the artwork includes both the MAX7461 and LM1881. Mainly because in my unusual app (no RSSI :( ) I highly doubt the MAX7461 will be fast enough; I plan on doing horz video line analysis, line by line. I also included RSSI inputs as an emergency back up plan.

Share this post


Link to post
Share on other sites

My needs are not as great as yours but I am thinking I will stick with the LM1881 and PIC as it is easy to upgrade/adjust in the software if I feel the need. I was just thinking to use the MAX7461 if it turned out to be particulaly good. The first option is also better for me as all the parts are availible in the UK.

Terry

Share this post


Link to post
Share on other sites

-AT-Killrah & Mr. RC-Cam

hecko,

I've got a simple question. Since I want to use audio on my DIY diversity receiver I need a chip for not only video switching (max4310) but also audio switching between coming from receiver a or receiver b, too.

So the question is whether I simply can use a 2nd max4310? Instead of connecting a video line to it, I would connect the audio output from the receivers to the 2 inputs... would this work? One max4310 switches between the both video outputs and the other between the both audio outputs..

Or do I need a more specialized chip like the max4585 for audio-switching?

ANY help is appreciated most,

Greets,

Marcus

Share this post


Link to post
Share on other sites

You can use the MAX4310, but it's specifically designed to have a very high bandwidth for video. You don't need that bandwidth for audio, so they must certainly have a cheaper analog mux that would be suitable. Now if you just want to make one unit and got free samples, go with it ;)

One thing to remember is that it is single-supply, so won't handle negative or AC-coupled signals. So, you either have to keep your receiver's audio output DC-coupled if it already is, or to bias the mux input yourself. Same for video.

Share this post


Link to post
Share on other sites

For audio switching you can use very low cost analog switches. Something like the ancient CD4066 will work. As mentioned, you either have to use bipolar supplies or bias the audio to work within a single supply powered part.

Share this post


Link to post
Share on other sites

-AT-Kilrah & Mr. RC-Cam

Thank you gentlemen for your help, I understand the point.

since I am currently in the developing stage of this project, I can change everything. But you got me right, it will be only very few (1-3) units and I want to use free samples (since I dont have any much money but dont want to give up the hobby).

so what woulb be the correct way to apporach this? I mean I think that I want the very same like you gentlemen have already or are planing to do, too.

I never have worked with dual +/- supply until now. Would be great if you coul give or point me to a kickstart regarding this topic.

(Telling me which chips you use for which purpose would be an other fine option since I dont have to figure out which one is the right one then)

Best greets,

Marcus

Share this post


Link to post
Share on other sites
I never have worked with dual +/- supply until now. Would be great if you coul give or point me to a kickstart regarding this topic.

If you wish to use a +/- supply: It can be as easy as using a second battery pack. Or, you can utilize a DC-DC switcher that provides the negative voltage. For example, http://focus.ti.com/docs/prod/folders/prin...int/pt5030.html. Switcher supplies can be problematic due to R/C EMI/RFI, so keep that in mind.

Share this post


Link to post
Share on other sites

hecko All!

Thanks for all suggestions, thanks very much..

I recently also received the MAX7461 samples..... they are easy to work with and I think they are exactly what we have been looking for in our LOS-alarms! You should give it a try, too.

Greets,

Marcus

Share this post


Link to post
Share on other sites

It is good to hear that that the MAX7461's are working out for you. I'm still waiting for my PCB's, but hopefully I will have good success too.

Share this post


Link to post
Share on other sites

-AT-Mr.RC-Cam

Yes, I hope that you will have good success, too. But the chips seem to be very nice... one initial stage test was sending a carrier signal only (tx turned on with no camera attached)... the LOS was pulled low as expected/hoped.

Next test will be how it reacts to missing/corrupt frames during transmission. I expect/hope it to work as fine as in the first case, too.

If so, this chip will be a beautiful replacement for the pic/lm1881 combo.. requiring tiny space and few external components.

Why you don't simply etch your pcb's yourself?

Greets,

Marcus

Share this post


Link to post
Share on other sites
Why you don't simply etch your pcb's yourself?

I did that for years, but I just don't enjoy the task at all. So, I have the professionals do it for me. I haven't stained the floor, or ruined a shirt, since the switch to using the fab vendors. :)

Share this post


Link to post
Share on other sites

Update on video diversity project: All the proto hardware is working and I've been tweaking the firmware.

Although I included a pair of MAX7461 Loss-Of-Sync chips on the board, I won't be using them. Instead, my video switching algorithms are performing Horz line analysis, which is not possible with the nifty little MAX chips. Instead, a pair of LM1881 sync detect IC's are being used, along with a fast microcontroller. Keep in mind that this design does not use the video Rx's RSSI resources, so it has to be fast and tricky.

The proto board has inputs for the two video sources and supports stereo audio (audio is switched too). There are two buffered video outputs (one for a monitor, another for glasses or DVR). The stereo audio output is also buffered.

To accommodate Rx's that do not have matched video signal output levels, the board includes a video balance control. Front LED's show the active video source (1 or 2) and a piezo sounder chirps when a video switch occurs. All these creature features are working, but I want to continue to optimize everything so that my first field tests go as well as possible. Not sure when that will be since I have some higher priority things in the way the next few weeks.

The following photos show the construction of the proto board. Nothing special, except that you can see that it takes a lot of RCA connectors to handle things.

post-6-1163548951_thumb.jpg

Share this post


Link to post
Share on other sites

For those that are interested in using the MAX7461 IC's, please note that they are SOT23-5 footprints. That means they are tiny! This photo shows their size (see yellow circles). Just compare them to the nearby 8-pin DIP IC or the 1/8W resistors. My advice is that it would be best to plan on creating a SMT PCB to use them.

Although I am not going to use the MAX IC's, they do work as advertised. Nifty little buggers, that they are.

post-6-1163549079_thumb.jpg

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...