Wiring pressure switch

[m1k3]

Hey i have been reading around how to wire the pressure switch and i am still confused do you just strip the pwm cable and and connect the black and white wires directly to the 2 prongs of theswitch then connect the the other side to digital input please correct me if im wrong

[Andrew Morris]

You can wire the switch as you said(directly connecting PWM wires to prongs). The way we do it on my team is connect other wires to the switch and put quick-connects on the ends. Then put quick-connects on the end of the PWM cable. This allows you to quickly and easily change the switch or the PWM if one or the other goes bad.

[m1k3]

other wires such as

[Andrew Morris]

Just any other wires. Just like 1 inch lengths of wire from each post. Not at team's shop right now so I can't get a picture but I'll post one as soon as possible

[robbrad]

There are different kinds of pressure switches. I'm not sure what "the pressure switch" may refer to. I didn't see one in my kit. The ones I am familiar with change resistence with the load applied, the lower the resistence, the more pressure. I hook up that kind of sensor in series with a 1/4W resistor and measure the voltage accross the sensor pins with ADC. Using the datasheet information about the resistence output, I can determine the load.

[Nate Laverdure]

Originally Posted by RyanCahoon

Battery-Breaker-Pressure Switch-Compressor

Careful. The pressure switch is not rated to 12 volts, so it must be wired through the robot controller.

2008 Manual <R96> The Nason pressure switch must be connected to the high-pressure side of the pneumatic
circuit (i.e. prior to the pressure regulator) to sense the “stored” pressure of the circuit. The
two wires from the pressure switch must be connected directly to a digital input and ground
terminal on the Robot Controller, and the controller must be programmed to sense the state
of the switch and operate the relay module that powers the compressor.

Last year's manual gives more detail:

2007 Manual <R103> The Nason pressure switch must be connected to the output end of one of the Clippard
tanks to sense the tank’s pressure. The two wires from the pressure switch must be
connected directly to a digital input and ground terminal on the Robot Controller, and the
controller must be programmed to sense the state of the switch and operate the relay
module that powers the compressor. The Parker pressure vent valve must be connected to
a Clippard tank such that, when manually operated, it will vent to the atmosphere to relieve
any stored pressure. The valve must be placed on the ROBOT so that it is visible and
accessible.

[Al Skierkiewicz]

Following the Robot section of the rulebook and the Tips and Guidelines, the pressure switch that is supplied in the KOP needs to be wired back to the digital inputs of the RC. The code for control of the compressor using this device (which is required if you are using pneumatics) is part of the default RC code. If you wish to write your own control software, merely copy and paste the lines that relate to compressor control from the default software.
The switch must use only the ground and digital input when using a PWM cable for interconnect. Please remember that one wire of the PWM is connected to the backup battery and must be insulated to prevent damage or failure of the backup battery system.

<R96> The Nason pressure switch must be connected to the high-pressure side of the pneumatic
circuit (i.e. prior to the pressure regulator) to sense the “stored” pressure of the circuit. The
two wires from the pressure switch must be connected directly to a digital input and ground
terminal on the Robot Controller, and the controller must be programmed to sense the state
of the switch and operate the relay module that powers the compressor.

[m1k3]

you are talking about the red wire one the pwm cable that you do not need what do you mean connect it to the back up battery? how do you connect it?

[mneary]

Do not connect the red wire; cut it and insulate it. Connect the other two wires to the pressure switch.

[m1k3]

thanks

[compwiz2008]

What ever you do, don't connect the pressure switch directly to the power of the compressor. We did this last year and it burned it out. What can I say, we were a rookie team.

[Al Skierkiewicz]

Originally Posted by compwiz2008

What ever you do, don't connect the pressure switch directly to the power of the compressor.

Robot rulebook prohibits this and it will be checked during inspections. See rule R96 above.

[m1k3]

do you soder the pwmto the prongs

[Al Skierkiewicz]

Originally Posted by m1k3

do you soder the pwmto the prongs

Use a crimp connector on the end of the PWM cable that attaches to the switch. Since the PWM cable is #24 wire or smaller, simply strip back about an inch of the insulation and fold the wire over twice. This will give you an equivalent wire size somewhere between #18 and #22, just the right size for a small crimp.
Never solder to the RC, use the female RC connector supplied with the PWM cable.