Lighting and uncontrollable motors

[OddOne]

In an earlier thread, I understand that the light needs to be hooked up to a relay. I was wondering if I could hook it up to one of my unused speed controlers and put in the code something like:

PWM5 = 255 'pwm5 will alsways be on full forward

Would this be ok? or do I have to use a Relay?


In another matter, my team is/was planning to hook one of the motors directly from the circuit breaker to the motor and then to the negative. Is this acceptable, or does that also have to be mounted to a speed controller?

Thanks
Mike -- The "Odd" One

[Brian Savitt]

It was to my understanding that the light HAS to be wired to a Relay, Im pretty sure thats truebecause we wanted to do that (wiring it to a speedcontroller) but I think we were denied our request to do that

Hope that helps.


Brian Team 56

[Curtis Williams]

I think that all motors must go through a relay or speed controller (depending on their power). The only exception is if you are using a motor as a non-functional decoration.

[thedillybar]

PWM1 = 254 will do the same thing as relay1_fwd = 1 and
PWM1 = 0 will do the same thing as relay1_rev = 1

PWM1 = 255 will not run at full foward, you need to use 254. As far as what's legal, you need to ask FIRST, but if you have to use a relay for the light, maybe you could use a speed controller to replace a relay somewhere else? Maybe for a solenoid or for the pump?

We're having the same problems because we're a rookie team and we only have 4 relays. We're asking local teams if we can borrow 1 or 2 of their spikes since most of them have plenty left over from previous years.

[CaptainPlaid]

I am almost positive that you must use a relay for the light. Besides Victors cost three times as much as Spikes. Maybe consider trading another team a Victor for three spikes. Or just take up a collection and buy one for $35.
With the motor question you need to consider what that motor will be doing. If it is a non-functional decoration or not it will be running before the start of the match if you hook it up in this manner. Depending on what it does, FIRST may not be real happy with that. You set your robot on the field and turn the power on, then when the match starts you are "Enabled". You would be bypassing this feature which could be a big problem.

[dets002]

I think that you need to use a spike, and putting it on Relay 8 would be best, as it is always on (in the default code).

[Keithicus]

Absolutely in no way should you EVER hook a motor up directly to the circuit breaker or fuse panel. The officials will definitely notice this during inspection and will make you change it, not to mention it can be a safety hazard. All motors must recieve power through a speed controller or relay, depending on the type of motor. Generally, the higher power motors (drill motor, chippy, fisher price, etc) may only be hooked up to a speed controller. For the other motors you can choose to use a speed controller or relay.

Look on pages 8 and 9 of this document:

Robot Rules & Specs
They show you a general wiring diagram and tell you what kind of control you can use for each motor.

Look at the end of this document to see what they check for when they inspect your robot:
Team Update #4

-Keith
Mentor #920

[Al Skierkiewicz]

Think of it this way...
All robot functions must be enabled/disabled through the competition port of the Operator Interface for safety of the competitors. Therefore nothing can run on the robot (except custom circuit board and robot controller) without the control of a speed controller or relay.
Good Luck All

[Curtis Williams]

I think you can also connect fans directly to the breaker panel without going through a speed controller or relay.

[OddOne]

All right, I got this all worked out, so thanks.

Mike
The "Odd" one