Traffic signal indicates garage door fully open

Our Expedition is an emergency vehicle with Streethawk light bar on the top.
If the garage door is not FULLY open, or does not fully open, the light bar could be damaged while severely damaging the garage door.

Any ideas how to install switches which willuminate the traffic signalamps according to door position?
RED = not clear.
YELLOW = clearing
GREEN = door fully open

I would like to use typical 15-amp wall switches which are cheap and heavy duty.
In metal boxes, they would also meet building codes using Romex.
(Must the Romex be inside metal conduit?)

I would power the traffic signal circuitry from the garage door light circuit.
If the door has been open and light off after (?) minutes, and I start to drive out, blocking the safety eye would illuminate the traffic signal which would indicate if the door was fully open.

Does anyone make magnetic switches which are not a fortune?

Thank you.

Robert

I would use a series of limit switches mounted on the track & a postioner (tab) mounted to the door.

Thank you.

What is a limit switch?

I was thinking of installing a magnet on a pawl on the top end of the door.
It would connect with another magnet glued to the toggle switch lever.

When the garage dooreaches full open, the magnet would push the
toggle switch ON to illuminate the green lamp.
When it pulls away, it pulls the switch OFF as the magnets separate and door continues away.

Design it based on how he door is likely to be most of the time. Meaning if you use limit switches or magnetic switches with relays, the relays are normally open most of the time (and not drawing any power), Hence:
1. Door is likely to be closed most of the time, so red,
2. As door comes off closed, is yellow
3. Door gets to top and green.

If you use three limit switchs they must have Normally Open (NO) and Normally Closed (NC) settings:
A. The bottom switch is NC feeding the red circuit (which is most of the time).
B. Door is activated and bottom switch changes from NC to NO. The NO setting feeds the yellow circuit, the second mid height limit switch,and also green circuit limit switch.
C. When the door reaches the mid height limit switch, it goes from NC to NO thus turning off the yellow circuit.
D. Door reaches fully open and activates high limit switch and goes from NO to NC. Since this high switch is powered by the lower limit switch, it feeds the green circuit.

Limit switches are available from McMaster-Carr or Grainger. You'll have to design some trip brackets depending on the type of switch selected.

I think this could be designed with just two limit switches, one at the bottom and one at the top and one relay. Lower switch is NC and red, door activated and lower switch comes off NC to NO and activates relay from NO to NC and activates yellow. The rlay is active only when door is midway open, which is not likely to be that often (when is door mdway??). When door hits upper limit switch, it drops the yellow light circuit relay and feeds the green circuit.

Another way to do this is mechanical. On the door jam install a swinging arm that will drop across the opening and tie it, with a rope, to the bottom of the door. As the door approches full up it will lift the arm out of the way. The arm only needs to be 2 foot long as it is only a visual. Think of a railroad crossing guard arm. Be fancy and put a small stop sign on it. The electrical is also real simple to do IF you have the experience. Friartuck's two switch circuit would be what I would use.

lg
no neat sig line

do you already have the traffic light?

Seems like it would be easier to have the door trigger the switch to illuminate a single light only when fully opened. Then train the drivers to not pull out unless the lamp is illuminated.

Robert Gift said:

I would like to use typical 15-amp wall switches which are cheap and heavy duty.

Click to expand...

Nooooo. Listen to FriarTuck...What you want are Microswitches rated for 120V/ and at least 10A. You can buy them w/roller tip, perfect for applications like this.

rwhite692 said:

Nooooo. Listen to FriarTuck...What you want are Microswitches rated for 120V/ and at least 10A. You can buy them w/roller tip, perfect for applications like this.

Click to expand...

He just needs one of them. Located where it will be activated by the top of the door when it is fully open. Something along the lines of an aircraft squat switch used by guy in the cockpit that the wheels are actually on the ground... which prevents to less aware pilots among us from retracting the undercarriage while parked..

Here is an example of what you want....

Limit Switch

I'm not a big fan of Automation Direct....but in this case the part is most likely made by Honeywell.....I prefer Allen Bradley....

BTW....you will not need a relay....just tie the output of the limit switch directy to a light.....look on that web site and you will also see lots of lights....I would suggest LED for the low power consumption and long life....

Does the door not fully open very often??

I think you are complicating things up with all the lights, how about just one green light for all the way up. A simple and easy way to do it is go low voltage using a Remcon Low Voltage Relays -R-115S / RC-120S and a switch wired to it at the end of the garage door travel to turn on a green light, done with plenty of time to enjoy a frosty beer and a motocross race.





Relay info:

Momentary switch type relay (3 wire)
Switches AC power ON and OFF using low voltage control circuit
Built in transformer, no step down transformers necessary
Single relay can be controlled by multiple switches and multiple relays can be controlled by single switch
Light #22 cable can be used to control relay instead of Romex or armored cable – significant time and cost savings
AC Voltage from 105 to 125V
AC Current up to 6.5A (1/4 HP max. motor load at 120V)
Frequency: 60Hz
Safe control switching: 10VDC max. and 10 milliamps max.

Click to expand...

I'd tape a post it note to the dash that reads "make sure the damn door is open before you leave", or glue a mirror to the wall....but to each his own.

The only thing I wanted to point out is that powering this whole "system" from the garage door opener light circuit has a pretty basic flaw. If the whole reason the door has not opened all the way is because of a power failure, a tripped circuit breaker or some sort of circuit board meltdown inside the opener.....your system is dark.