Forums > MaxMSP

OT: TRS cables for sensors connecting to Doepfer Pocket Electronics

February 11, 2006 | 12:10 am

What’s the longest TRS cables I can use to connect sensors to the Doepfer
Pocket Electronics box I built, which has 16 TRS 1/4" jacks in it. Each
sensor will be connected to a 1/4" TRS Jack. I’ll then be able to test
different sensors with cables. Have people had better luck with certain TRS
cables and certain lengths? I’m mostly going to be using Interlink force
sensors and Sharp IR sensors, but might try some other sensors as well.

Thanks.


February 11, 2006 | 8:19 pm

It depends on the sensor and the cabling. Go with good audio cabling
- perhaps canare starquad. The sensors themselves will be the big
limiting factor. Usually if the cable gets too long, you’ll see
reduced range from the sensor, flaky data, and finally nothing at all.

One trick to help get longer cable runs is to use an op-amp set as a
voltage follower, which will provide more power to the sensor signal,
as well as make it low impedance.

My guess is that the Sharp IR sensor is the one that will have the
most trouble with long cables. I guess you’ll find out.


February 14, 2006 | 4:37 am

But considering I think I’m going to be looking on ebay for the cheapest
bulk price for the most cables, should I be looking at a certain length. Is
3′ my best bet? Or would 6′ do me fine?


February 14, 2006 | 8:20 pm

I’ve used those particular sensors with some pretty cheap headphone cable — it was shielded. I kept the runs <6', and then made it to an op amp circuit. The subsequent 25' run was through serial cable DB-25 to DB-25. (I had 16 sensors.)

I didn’t have any troubles with noise in this setup. I did have a calibrator at the Max end, and set did that before each show.

In short, I think you should be fine.

mz


Viewing 4 posts - 1 through 4 (of 4 total)