Wipe Generator
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I had some time today as I’m waiting on parts to arrive and an OMF to cut. I figured it wouldn’t be a bad time to try my best at making the wipe generator work. It’s a box that takes your video signal for the booth and adds a white bar that streams across it. It allows you to cue people visually. People are all different and everyone takes a cue differently. I wanted to get this thing working and have another option to offer if someone can’t catch a rhythm from beeps.
The box was out of use because:
A) the company that produced it has long closed shop (so no info on it could be gotten)
B) it required a contact closure to be triggered as opposed to something like tone or midi controls
The best solution was to find some type of circuit that could translate a tone pop to a contact closure or trigger. Enter the optocoupler, an integrated circuit utilizing an LED and a phototransistor. The light takes the tone pop’s voltage (which needed to be increased +19db to actually fire it) and changes it from an analog signal, to light which is emitted onto a phototransistor, and changed into a logic signal.
After protoboarding it with some Cat5e cable and getting it to finally fire with a 9v battery. I put it all in a project box and packed it into the rack.
7 Comments
Hello,
I’m trying to make this same circuit and cannot get it to fire with a 9v battery, could you tell me what you did to make it work?
I’m trying to send and audio signal through an RCA jack to a contact closure. Thanks for any help you can give me……. Jim
Hey Jim,
This circuit is using the analog audio output of my interface to change from logic low to logic high. Check the datasheet on the optocoupler you’ve gotten yourself. 9v directly might be a bit much. This was an ambitious project for me and I wasn’t really sure it would work till I was done. Are you trying to use audio to trigger something? I know midi-relays are also good for that purpose.
Regards,
J
Hey Josh,
I originally seen your post on a DIY audio forum about analog signal to contact closure.
I bought the same opto and resistor that was listed in that post and everything seems to be connected right. I am trying to trigger a controller for a pneumatic animated prop, its for Halloween. The controller needs just a simple contact closure to fire. The prop also has video that goes with it and I have multiple channels for sound.
I would like to trigger the controller through one of the audio channels with some tone or sound. The audio is coming from a surround receiver.
Did you get your circuit to fire with the 9v battery? If so how.
Thanks!!!!!!!!
Jim
OK good,
So I was originally going to say that maybe the output was not great enough as consumer audio is at about 1.2v where as professional audio translates into about 4 volts…
Which is why I assume I had to crank up the volume considerably to get it to fire and used a really low frequency tone. But if you can’t get it to go with a 9v something is up. Honestly I never took a volt meter to the output to check what it’s reading at. If it won’t fire with a 9v battery then something may be wrong. Do you have a spare optocoupler to route out the possibility of a bad chip? I do remember sweeping the contacts by gently brushing the leads to the positive contact and having it fire. I think if I adjusted the resistor value I could get it to fire but actually a new tool in software has made this less useful than before. I still use it for VO sessions but ADR now has a complex routing manager in the box, which is great. I messaged Simon7000 to see if he could elaborate.
Josh
Scratch that! Changing the resistor value will not change the LED’s brightness just remove the protection of the IC. Do you have a data sheet for this trigger?
J
Here’s a link to the manual for the controller,
I have used some of this company’s controllers in the past but have not bought this one yet. All the other controllers from them used just a contact closure to trigger. After looking at the manual above, it looks like this one needs a powered trigger. 5-24 volts and I think it says the are already optically isolated. I should have looked at the manual but just assumed it was the same as the others that I’ve used in the past. Any ideas how I can trigger this controller with audio. Thanks!!!!!!!
Jim
Hey Jim,
Interesting device. I found the manual at
It seems like it has a bunch of other stuff to go with it for control and that box is the terminus so to speak where everything is connected for triggering. It looks like it requires a little automation and sensor’s rather than sounds… That said you could probably have a microphone as a sensor but I bet you it wouldn’t be reliable as people won’t reliably make the same amount of noise and your just asking for a whole bunch of false positives! Fortunately that thing looks like it takes a whopping load of other types of sensors, like pressure pads and motion detectors to be sure you won’t have corpses springing from a grave when the neighbour’s dog barks. Getting it to trigger a sound and a pneumatic trigger at once is probably in there as well. It probably will replay a scene of automation you’d program.
Trigger activated:
Play scene
Pop skull up
Play WAV file Scream.wav
Smoke machine on
End
Trigger wait 30 seconds…. etc