Pressure switch as a replacement for expensive Tape Switches

[James Peters]

Do you duct tape down the whole switch on these as you would on the tape switch?

I tape a small piece down right where the tube is pushed onto the switch, then pull the tube straight over the line, pulling a little to give some tension, tape down the other end with another small piece -- then tape the whole thing down.

last few weeks it hasn't been working reliably...

[Marcos Soulsby-Monroy]

Do you duct tape down the whole switch on these as you would on the tape switch?

[James Peters]

2nd impression from our last session a week ago-- 100% reliable!

Just had to *pull the tubes taut* before duct-taping them down. Worked awesomely.






Brings down the cost of the 2-lane system by $200 or so!

We'll keep testing this throughout the winter...

[James Peters]

pat

1st impressions from last week --- these worked pretty well!!

michael did a "pro" soldering job and refreshed all the connections.

the start line was 100% reliable. the finish line, we had to give it one final pump while crossing the line, and it was about 75% reliable. that could have been due to a lot of things, we simply duct taped the tubes to the concrete floor of the garage, so a small inconsistency could have reduced reliability.

i'm thinking of some way to tape or glue these down to the center of 3" wide metal strips, then all we have to do is secure the metal strips to the asphalt surface each time, wouldn't have to disturb the tubing at all.

since the rain and snow is imminent, i suspect we'll be doing garage cyber again this coming sunday, and will let you know how round 2 goes!

james

[Pat Chewning]

I am experimenting with some pressure switches as a replacement for expensive tape switches.

The switches I have are:
Signal Lux type P1 See http://www.signal-lux.com
You can order them at: http://www.allelectronics.com/ (seek: Switches/Pressure)


These switches are a single-pole single-throw normally-open (SPST NO) switch that is activated by either pressure or vacuum.

I modify them like this:
A) Attach 4mm flexible tubing to the pressure side.
B) Plug end of 4mm tube (4mm screw works)
C) Unscrew the pressure-adjustment body and remove the spring (to set at lowest possible pressure setting)
D) Solder wires for your favorite timing system

See picture here:

Advantages:
1) Tubing does not fail when kinked.
2) Cost: $1 for the switch, $0.60 for the tubing (Compare to $25.00 for a 2-foot tapeswitch)
3) Make them whatever length you need by cutting tubing.

Disadvantages:
1) Assembly required (a bit more than for Tapeswitches)

Unknowns:
1) Reliability
2) Uniform and repeatable time from rolling over the tube to activation of the signal.

Experiment at your own risk