Electronics

yfd33 · Joined: 16 Jun 2006 Posts: 2

I really hope someone can help me with this project. I am new to this forum but appreciate any feedback.

I am working on a fire department ladder/aerial truck. The problem: There are strobe lights that are mounted on the bucket/basket of the truck that normally flash when switched on from the cab. The wire that runs from the cab to the lights is broken somewhere in the swivel assembly. A swivel is the part on the turntable of the ladder truck where the wiring, hydraulics, and water pipe pass through allowing 360 degrees of turning. The swivel needs to be replaced if we wish to fix this wire. This is not an option at this time due to the cost being over $10,000 to replace with labor.

Here's the deal: There is still plenty of 12 volt power to the bucket area. There are power leads in the bucket area that have constant 12v power as soon as the vehicle is turned on. This power would work fine, but the lights would constantly flash when the vehicle is on- even if not responding to a fire call. The idea: to have a 12 volt relay mounted in the bucket area feeding off of the constant 12 volt power. This relay can be operated remotely to be turned on and off from the cab via a radio/remote control. The remote control can not be like a garage door opener. It must be able to be hardwired into a common on/off (not momentary) 12volt automotive switch.

Questions:
-Where can I buy this transmitter/receiver combo that works with 12 volt systems on a radio frequency, not infrared and preferrably not a keychain remote.
-How can a wire the on/off 12volt switch in the cab to send this rf signal to the relay from a constant on/off switch? I understand how I could wire a momentary switch into the transmitter by simply using the garage door opener-style transmitter and hard wiring it to a switch. But it must use the trucks existing switch whcih is constant on/off, not momentary on/off. The reason: There are several switches for turning on all of the emergency lighting. All of these switches are tied into one MASTER switch. The firemen simply hit the MASTER switch which feeds power to all of the switches that were left in the on position.

Please, any help is appreciated. I am not an electronics genius so please be specific and use lay terms if possible. Your help is greatly appreciated in advance!
-TONY

neon · Joined: 25 Feb 2006 Posts: 593

I don't think you need an rf transmitter all you need an on/off switch in the cab or whatever. 12v lamps runs into quite of bit of power i would think that putting a string of LED will provide the candle power for normal warning light some can provide > 15000 alumels that is enough if strung in series and some in parallel. the flashing can be setup with an LM555 and a driver transistor 2n3055. Well think about that see if that is satisfactory. take care

yfd33 · Joined: 16 Jun 2006 Posts: 2

There is no way to run a switch from the cab to the bucket area. It must run on a RF switch. No wiring can be run as the turret turns the wire will wrap and break. This is the purpose of a swivel.

neon · Joined: 25 Feb 2006 Posts: 593

I see i am not a fireman. How about putting the switch after the swinging turret. is it possible?. you see there are devices that can be used but can they be reliable is the question because of your enviroment. A carage dor opener reciever transmiiter will work. an LM555 running at 30kc will work with just a tweaker as an input and a mike reciever.An infrared will work too even a photocell will work. my next question is can you implement such a device? the other solution go to goodwill industry store pick up an old TV with remote control $10 20 max and rip the ir sensor and add some interface to the thing you are there.just some ideas. or go to electroniczone.com they have kits and some design and you may find what you want.

	Electronics Forum Index -> Design	All times are GMT
Page 1 of 1