This is topic Help with sound c/o wiring in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Don Furr (Member # 1469) on 07-07-2003, 10:26 PM:
I'm finishing my new booth and I'm bogged down on the wiring for my sound change over switches. Can anyone email a wiring plan using a Smart Mod 2b? It defaults to projector #1 until you short and hold the ground/change over lugs on the 2b. I prefer monentary push to change switches.
Thanks in advance for any help.
Don
dndcine@mindspring.com
Posted by Tim Reed (Member # 137) on 07-07-2003, 10:57 PM:
Just use a Potter and Brumfield latching relay. One coil latches the contacts, the other releases it.
Posted by Paul G. Thompson (Member # 655) on 07-08-2003, 01:23 AM:
Tim mentioned the easiest way to do it. By the way, you can trigger the latching relay off the change-over douser in most cases.
Posted by John Anastasio (Member # 607) on 07-08-2003, 05:30 AM:
I had a Smart processor that worked the same way. I wired a latching pushbutton switch to the contacts and mounted it in a small project box that I could hold in my hand. It had Velcro on the back and I'd just stick it to the back of whichever machine had the next reel ready, then just grab the box to make the changeover. The wire was long enough to be able to watch for cues and it was convenient because it was so moveable.
Posted by Dave Macaulay (Member # 813) on 07-08-2003, 12:34 PM:
The P&B mechanical latching relay costs a bunch but it's probably the best solution.
The problem is with the picture changeover, unless you use momentary buttons it's hard to give the short pulse required - most changeover coils burn out in no time if you try leaving the power on. With 120V changeovers and a 120V latching relay there's no problem, SPST buttons and the relay are all you need. Unless you want separate picture and sound changeover switches of course... maybe a classic foot pedal system?
You can avoid the expensive relay using 3 2C relays and momentary buttons, one relay wired with electrical latching plus a pair following the changeover buttons and activating the picture changeovers plus toggling the sound changeover relay. Unlike the mechanical latch relay this will "forget" it's on projector 2 if the power hiccups though. Plus relay life might be a problem as the latching relay will be powered half the time unlike the pulsed mechanical one.
Posted by Daryl C. W. O'Shea (Member # 1303) on 07-08-2003, 01:27 PM:
The least expensive way to do it would be to use a DPDT switch at one machine and a SPDT switch at the other, and have separate sound and picture changeover controls.
If you wire it something like this, you can changeover (the sound) between each projector (from either projector), regardless of either switches current position.
If you label your switches like this:
Switch 1 (DPDT)
1A1 1A2
1Y1 1Y2
1B1 1B2
Switch 2 (SPDT)
2A
2Y
2B
Then wire as follows:
P1 to 1A1 to 1B2
P2 to 1B1 to 1A2
GND to 2Y
1Y1 to 2A
1Y2 to 2B
There's the two dollar solution... plus you'll be able to do seperate sound and picture changeovers (with the addition of a seperate picture changeover button that you probably already have) which will allow you to do changeovers even more seemlessly. ![[Smile]](smile.gif)
Posted by Paul G. Thompson (Member # 655) on 07-08-2003, 02:13 PM:
I don't think the latching relays are that expensive. The "ice cube" style is probably the cheapest.
Posted by Steve Guttag (Member # 268) on 07-08-2003, 07:07 PM:
The last time I price checked the P&B KB or KBP style relays they were knocking over $150 a pop and special order items in most places. I agree it is the best thing going for that sort of function.
Then again, many of the newer processors now take pulsed c/o commands (CP-500 and CP-650 do) so just a couple of $10-15 jobbers will do you and there is no chance the processor will be out of sync with the projectors.
Steve
Posted by Tim Sherman (Member # 569) on 07-09-2003, 02:54 AM:
Doesn't the mod 2b use a pulse system? Nothing like being able to connect to the automation.
Posted by Don Furr (Member # 1469) on 07-09-2003, 05:32 AM:
Hi Tim........
No, the Mod 2-B is a "make" and hold on the ground/c/o lug. My old Smart 300 was a pluse but not this one.
Thanks for all the help with my question. I think I have enough knowledge to proceed. You guys are great!!
Posted by Matthew Bailey (Member # 601) on 07-09-2003, 11:51 AM:
I know where you could get some switches & relays for maybe free. From bowling equipment techs & mechanics that work at bowling alleys. They shold have spares which they use with pinsetters & ball returns. Maybe you can ask someone in the forum at www.bowltech.com
Posted by Tim Reed (Member # 137) on 07-09-2003, 01:28 PM:
Humm... I wonder what that field pays?
Posted by Daryl C. W. O'Shea (Member # 1303) on 07-27-2003, 05:14 AM:
How'd it go Don?
Posted by Don Furr (Member # 1469) on 07-27-2003, 06:10 AM:
Dayrl....
All finished!! Used a relay system given to me by a friend. I installed c/o buttons on the exciter lamps doors and all is perfect. Now as soon as my second ORC lamp is delivered I'll be completely through. My XL's have 6000 Kelmar arms but I'm resisting the large reel route. Been there done that. Something about the sound of that ding, ding, ding.!!! I come from the "old" school. I was doing changeovers on Supers when I was 14 years old.....I'm 55 now!
Thanks for asking.
Don
Posted by Frank Angel (Member # 248) on 07-27-2003, 09:48 AM:
Don,
Congrats....nice when something you put together yourself actually works. I was going to post the circuit I used for my change-over but these guys were faster. I went the relay route also which enabled me to add LED indication at the switch. If I had more room, I would have used sexy lighted switches. I also added a MUTE switch with flashing LED next to the switch and have found that very useful.
Because I run lots of old prints, picture change-over remains separated from sound change-over and is switched by on one of those nice, big, macho footswitches. Wouldn't have it any other way. I can't tell you the number of times it was imperative that I let the sound on that last 21 frames of the outgoing reel play after the picture is switched.
And how lucky you are to have your own personal oil wells in your booth. Gotta love those XLs! BTW, who needs Kelmar arms when you can run 2000ft reels in those massive Simplex long-play magazines?! The cinema gods say, NEVER apologize for running 2000ft reels.
Frank
Posted by Don Furr (Member # 1469) on 07-27-2003, 12:57 PM:
Hi Frank.......
Really the reason I put on Kelmar arms is because my XL's had nothing when I took possession! These XL's are soooooo much fun to operate. I run a pair of JJ's at a part time job (I'm retired) but I'm still partial to the XL's.
Don
Posted by Frank Angel (Member # 248) on 07-28-2003, 03:28 PM:
Don,
To know them is to love them. ![[Big Grin]](biggrin.gif)
Actually, I have been running 2000footers in the big theatre for years (decades, actually). Years ago when I got the chance to put in the 7000ft magazines that were being thrown out when a neighborhood theatre closed, I couldn't resist. I still only run 2000ft, but damn those big mags look awesome!
Frank
Posted by Daryl C. W. O'Shea (Member # 1303) on 07-28-2003, 08:43 PM:
Good to hear you got it working Don. Hope you have fun with it all!
Posted by System Notices (Member # 2357) on 08-20-2004, 08:01 PM:
It has been 388 days since the last post.
Posted by Scott Norwood (Member # 30) on 08-20-2004, 08:01 PM:
Bump.
Does anyone have a wiring diagram for a "Kelmar ES-7200-B C/O Module"? This is the box with the "Normal/Emergency" switch which was originally designed to switch the exciter lamp for a Kelmar mono sound system. It has a P&B latching relay and two switches inside. I've figured out how to make it do what I want (connect to pushbuttons or footpedals along with picture c/o to toggle closed/open to control sound c/o on my CP65), but I'd kind of like to have the original wiring diagram in case I ever have the need to put it back into its original configuration.
Thanks.
(No, it's not in the Kelmar AS-7200 manual on F-T...I looked.)
Posted by Mark Gulbrandsen (Member # 72) on 08-21-2004, 11:01 AM:
"Humm... I wonder what that field pays?"
Tim,
I once knew a person that was sent to "Bowling Alley Repair School" at either AMF or Brunswick, can't remember which and doesn't really matter. He was a maintainance guy for someone that I worked for in the past and had the bowling machine repairs more or less dumped on him. He was always underpaid and over worked. Hope that gives you some clue.....
Mark Gulbrandsen
Posted by Steve Kraus (Member # 476) on 08-21-2004, 11:48 AM: