mini powerhorn mod

[paizano1]

I thought some could use this information.

I have modded a mini powerhorn so that it has an isolated pair of contacts that can turn other things on while the siren is triggered from the home security system.

I took the 2 white wires off of the piezo speaker in the mini and wired 1 to the coil part of a 12v reed relay, the other wire i put a diode in line before connecting to the other end of the coil on relay.  The contacts of the reed itself are wired to a female headphone jack or similar jack.  A small hole is drilled in the side of the case for the jack to stick out.  Everything is hot glued in place. The case is reassembled and that is it.

I have a separate siren that is powered by a 12v transformer.  In place of the switch that turns on the siren, I wire in a male headphone jack, this is then plugged into the modded mini.  Now when the siren trips, it connects the wires as though it were a switch.

The mini is also silent because the piezo is disconnected, this stops from drawing attention to it, which stops from the power being disconnected.

the separate siren is wired into the cold air return of the furnace. which makes for a really really loud siren that sounds when the system is triggered.

I have never felt that the mini or large powerhorn were really that loud, but with this mod, it can be as loud as your new external siren.

[dave w]

Nice!   

[HA Dave]

...... I have modded a mini powerhorn so that it has an isolated pair of contacts that can turn other things on while the siren is triggered from the home security system.

Excellent!!!! You got a helpful from me.

[JMac]

Fantastic - could you give us a parts list so that we know the specific parts that worked for you?  This is definitely a solution of the "external siren" problem several have asked about.

[HA Dave]

Fantastic - could you give us a parts list so that we know the specific parts that worked for you?  This is definitely a solution of the "external siren" problem several have asked about.

Yes... pictures are nice too.

[Brian H]

 
Good work. Thanks for sharing.
Parts list as mentioned would be nice.
I find it interesting, that the high impedance sounder driver, was able to drive the relay.

[Kramer Chins]

I agree with all of the above !!!!

Parts List and Pics...................

[paizano1]

Here is the list:
1 radioshack reed relay part#275-0233 12vdc
1 female headphone jack- had laying around in box of stuff
1 RG2-70 diode- again had just laying around from surplus, i don't think diode type is important.

On the diode, when i set of the siren and read voltage it was in the AC range not DC, Then after I put the diode on 1 leg of piezo wire my meter now read 11-13 volts DC.  I think just about any diode would do fine, as long as voltage rating is high enough.

hope the picts are ok, camera focus is hard at close range.

[paizano1]

one other thing, the amp rating of relay is only .5amp, so if you want to trigger something other than a siren and it has a higher rating you will need to build a separate coil relay circuit that is turned on by the reed relay, but can handle higher amps.  Discover circuits is a good place to find these types of schematics for free.  Please feel free to modify and post any ideas you feel are better. This was just a quick thing i thought of, and the funny thing was--it worked.

[Knightrider]

paizano1,

Thanks for the info.  A very useful mod indeed. Bet you see your helpful rating swell. 

[Kramer Chins]

  Got a HELPFUL from me.....

[tom j]

...... I have modded a mini powerhorn so that it has an isolated pair of contacts that can turn other things on while the siren is triggered from the home security system.

Excellent!!!! You got a helpful from me.

Me To! I'm assuming you could also hook this up to an outside siren? But how large??

Tom j.

[paizano1]

I am not sure how large a horn is possible.  The reed relay is only rated at 1 amp, but you could use the reed relay to trigger a separate relay circuit with a higher amp rating.  Just think of the modification as a simple switch triggered by the alarm and your possibilities are pretty much endless. 

On another note, thank you to all those who have given me helpfuls. Means a lot coming from those members who have helped me with all my problems.

[tom j]

I am not sure how large a horn is possible.  The reed relay is only rated at 1 amp, but you could use the reed relay to trigger a separate relay circuit with a higher amp rating.  Just think of the modification as a simple switch triggered by the alarm and your possibilities are pretty much endless. 

On another note, thank you to all those who have given me helpfuls. Means a lot coming from those members who have helped me with all my problems.

Thanks Paizano1 how about a siren like whats on a a car alarm, and what should I look for amperage?? this is DC so I don't over load it. Thanks!!

Tom j.

[paizano1]

a car alarm siren should work just fine. the one that i am using is similar to a car alarm siren, it is 12-15VDC rating, it is also a piezo siren like the one removed from the powerhorn only much much louder. and the nice thing about the mod is it allows you to control just about anything with the alarm. I also powered the siren with a wall transformer rated at 12volts and about 1000mah. 

on a different note make sure the siren you use is self contained with its own driver circuit to create the siren, some car alarms use the brain unit to generate the sound. to test this just hook up to power and see what happens.  Sorry took a couple days to respond was busy with some other things.  Sometimes "electronics goldmine and allelectronics" have sirens and piezos. 

remember mounting in the vent system makes for nice effect and trouble to locate.