I was wondering if anyone sees a problem with my idea so far, I think I have the wiring correct but I may be missing something.
I figured I’d go with latching relays so I wouldn’t have just a few sec talk time with the PA, since key fob transmitters aren’t allowed by law to last more then a few seconds. The LM317 circuit is to replace the 1.5 volt AA battery in the Microphone receiver so I don’t have to keep replacing or recharging batteries for it. I know I won’t have too far a range with this but I work pizza delivery and I will be using this either from inside the car or within 25-50 feet and not feel like walking back to my car to use either the PA or the Shockers to get customer’s attention. (yes I have used the train horn to get peoples attention before, one couple was busy screwing when I first did it :D) Also the PA system I have is a FedSig PA300 the power switch is connected to the wiring harness in the back of the unit so no need for another power line for that.
The only issue I see is that if I use the latching relay for the train horn, I’ll have the entire tank drain before I can switch it off so I’ll probably use a regular relay for that instead. Also the latching relays require just momentary pulses to turn on and off so that a key fob receiver can switch them fine. The volume on the PA is going to be set during install and testing and left at the best volume/sound quality.
I’m trying to keep things stealth as much as I can, there isn’t a whole lot of room to mount the main unit of the PA in the front, so I’m going to mount it in the back of my car. The xB has a foam shelf over the spare tire and under a false floor that I’m trying to re-fabricate with foam board and fiberglass that’s going to hold my amplifier and the main PA unit. That and I’m not quite sure how much of a drain it would be on my battery to leave it on all day and night.
So instead of running to the back lifting everything up to turn on the system it’ll be hooked up to a key fob to turn on and off when I want. All the hassle goes into building it none to operate it.
Here’s a pic of the fob hardware the antenna broke off during shipment so I resoldered it back on, and touched up a bunch of the solder points on the back. Got it cheap off of ebay from seller great-digital for $9 chinese made but these days what electronics aren’t from there. Just gotta touch up the cruddy solder job they did and it works great. I’m going to remount the key fob into another case with the internals of a wireless microphone so when I’m done it’ll be in a all-in-one case.
Now the problems are that the key fob uses the mini 12v A23 battery so I’m going to have to come up with a way to get a better run time since they are only about 40maH and I’m going to be screwing around with this new setup quite a lot. Then there’s the placement of the antenna I’m
thinking I’m going roof mount next to the stereo antenna, so I can use this
in a parking lot to find my car easier.
