12 volt trigger query

[cameronl]

hi there all

I'm having some trouble configuring my 12 volt trigger. I want it to drop my pj screen when either the tv or httpc source is selected. I don't want this to happen if the balanced cd is selected.

It seems though, that the 12volt trigger can only select 1 source to activate the trigger i.e. only when tv is selected.

I don't use the c2 for video switching.

Has any one out there done this type of thing before?

thanks for your help.

CaM

[MarkR]

Hey, sorry I can't help with your problem but I just noticed your location(s), thats one heck of a commute to work.

[cameronl]

indeed, I move around

hi there, yes - I live in europe or new zealand which means life is always interesting

CaM

[cameronl]

Anyone got an idea for a work around or a stand alone product?

thanks

CaM

[Peter Nielsen]

Yes. Use 2 trigger ouputs. Set one output to trigger on one source, and the other output to trigger on the other source.

Run each positive output through a diode and combine them into one. To construct a cable like this you need two male 3.5 connectors, two 1N4148 diodes and one female 3.5 connector. Total cost less than $10 + labor...

Peter

[cameronl]

hi Peter, I was thinking of using 2 12v's into one but I wasn't sure how to proced. I'll look into that.

thanks for your help.

CaM

[Karma]

HI All,
This is my first post on this forum since I have B&W and Krell. So, HI y'all.

Cameronl,
What you want to do can be done but unless you are quite familiar with electronics I would leave it to an expert. If it is done wrong it could have serious consequences.

I recently discovered my trigger signals (I'm a newbe to HT though very experienced in audio and electronics). I have performed logic operations with my trigger signals from multiple sources. My Denon 3805 has two triggers and each can be programmed for any or all combinations of the inputs. It's very flexible.

Check out your local hi fi repairmen. Be careful because not all are familiar with logic operations. What you want to do is simple but how to do it is not common knowledge. It will be a simple custom design. In my repair shop this would probably be a $100 ($60 per hour) job depending on how it had to be packaged. That's just a rough estimate based on very limited knowledge of your equipment.

Sparky

[Peter Nielsen]

Yep, $100 per hour sounds fair. It's a 20 minute job. Gimme $30 plus shipping and I'll build you the cable :B

Peter

[Karma]

HI Peter,
Back off. I was just trying to be helpful not incite a riot. If you can do it for that amount, do it. I run a business, not a charity. And the work and workmanship is professional. I repeat, back off!

Get your facts straight. I said $100 total at a rate of $60 an hour or about 1.5 hours of work.

BTW, I like your system.

Sparky

[Peter Nielsen]

Back off?!??? Who? As a professional, you better sponsor this forum if you're going to sell cables here (custom made or not). Please re-read the forum rules!

Maybe the forum owner's company www.catcables.com can make the cable...?

Peter

[Karma]

HI Peter,
I misspoke. I am no longer involved in the comercial end of hi fi. I was only trying to make a point. It is easy for an amateur to complain about prices when they are not worried about making a living from their work. Your labor is free. A business cannot function that way. Profit is essential. Little projects my customers brought to me to get them out of trouble I usually declined. They were doing a hobby. Not me. It's a totally different situation when you are running a business.

Where did you get the idea that I build cables commercially? Never have, never will. Did I say that? I do, however, make my own cables from my own designs. In spite of requests I have never wanted to get into the cable business. I'll leave that to CAT; a professional who does it right.

Sparky

[Peter Nielsen]

It is easy for an amateur to complain about prices when they are not worried about making a living from their work. Your labor is free.

Well, with a background with more than 10 years in the electronics industry I would hardly call my self an amateur. :B

Unfortunately jobs in the electronics industry are not very lucrative, so my daytime job for the past 10 years is computer related (programming), and I have to leave the electronics for my spare time...

A trigger cable like this does not require expenisive parts. Two plugs, one jack, and two diodes cost $1.52 from Mouser.com In addition to this, some wire and shrink tubing is needed... Maybe a dollar worth or so. If I want $30 for a cable with $2.50 worth parts, you can hardly say that my work is free :T

That said, if a DIYer goes to Radioshack to pick up the same $1.52 Mouser parts, the bill may easily end up at $15 or more... Talk about price gouging!

Peter

[Chris D]

Easy... easy...

I think think there was a simple misunderstanding here based on the written format of a discussion forum.

[slayer]

It's easy to take someone the wrong way and get fired up. Peter and I got off on the wrong foot when I first joined the forum. It was quickly resolved as a simple misunderstanding and I soon realized that Peter is a good guy. It sounded to me that he is just trying to help out another member here on the forum. He has done so with other members in the past and with myself as well.
After reading all the posts, I'm not offended by either. I think both are right here. Karma was just saying that if he did something like this at his shop he would charge around $100. So when looking for someone to do it for you, expect to pay close to this.
Peter just said that it would only take him 20min or so in his spare time and a few bucks to make it, so he would help him out for around $30 + shipping.
Either one sounds bad to me. Both are offering something useful. One is information, the other is a good deal. Now kiss and make up!

[VT Dan]

Peter, It sounds like you know how to fix my problem.
I have my Epson Powerlite 1080 Home Cinema's trigger connected to my Elite Cinetension screen. I made up a wire on my own, but without diodes. How do they fit in the circuit?
My problem is that the screen does a quick down/up cycle when I power on the projector. It then comes down as it should. Does the same in reverse when I power off. I am afraid this extra action will prematurely wear out the motor in my screen.
Thanks for any assistance.

[Peter Nielsen]

I made up a wire on my own, but without diodes. How do they fit in the circuit?

Are you using two trigger sources? (E.g. projector and TV). The diodes were suggested in situations where you have two sources of trigger voltage that you need to combine into one single trigger input on the projector.

My problem is that the screen does a quick down/up cycle when I power on the projector. It then comes down as it should. Does the same in reverse when I power off. I am afraid this extra action will prematurely wear out the motor in my screen.

This sounds like a problem with the screen controller. It should not be that sensitive/quick to react to a change in the trigger voltage.

The problem can possibly be cured by adding a diode, resistor, and capacitor. If not, then a more elaborate circuit may be needed.

See this schematic for a suggestion:



Component values will most likely need to be tweaked (by experimentation) to match your screen controller and PJ (for instance a larger capacitor or smaller resistor may be required).

Peter

[VT Dan]

Thanks Peter.
I am using just one trigger source, the Epson projector.
I did just as you said; ~ $4.00 at Radio Shack.

I tested the ckt. and it improved! The premature cycle of the screen lessened. The interval between when it goes down to when it goes right back up lessened, probably half the time. It did not cycle at all when powering off.

Which component's value do you recommend I fiddle with?

I'm thinking increase the capacitor, but am not 100% sure and am wary of frying my shiny new theater components.

-Dan

[Peter Nielsen]

First try to modify the circuit like this and see if it improves things:



This modified schematics is better in the sense that it gives the same characteristics for both on/off (up/down). Thus, if the previous circuit solved the problem in one direction, then this circuit may work in both directions without changing the value of the capacitor. Try this first!

If modifying the circuit does not help, then try to use a 100u or 1000u capacitor instead of 10u. (Of course, if the circuit "almost" works after the modification, then you may want to try to only increase the value slightly, say use 22u or 47u).

If 10u gave you a noticable difference, then 100u will probaby do the job and eliminate the problem that bothers you.

In combination with the modified schematics below, a large capacitor of 1000u will probably give you a noticable delay of a few seconds before the screen goes down or comes up... You may like this, or not. Give it a try and see how you like it. The capacitors are relatively inexpensive! :T

BTW, make sure the capacitor is rated for at least 16 volts or more, e.g. 10u/16V, 100u/16V, or 1000u/16V.

Peter

[VT Dan]

:T
Success !!!
Peter, you are the man! I tried the modified circuit that you suggested; no change.
So I replaced the 10uf cap. with the 100uf as you suggested, using the modified schematic.

Perfect. There is no noticable extra delay before the screen comes down, everything seems as it should.

To make it sturdier, I actually put it on a little bread board with terminals.

I taped it up and it tucks up into my drop ceiling out of sight over the projector.

Thanks Again,
Dan

[Peter Nielsen]

Great!!! Thanks for letting us all know it works :T :B

Peter