I think I want a relay

Guest
I ride a <a href="http://www.policemotorcycleescort.com">motorcycle</a>
for a living, as a funeral escort. We're not allowed to use sirens, but
we can use air horns. We use a Whelen electronic air horn.

I'm getting my own bike--a retired CHP BMW R1100RT-P. All the CHP gear
has been stripped, which means I need to re-outfit it for escort use. I
want to tweak the air horn a bit, and get a relay that will "stutter"
the air horn, like the phaser siren sound, something like &lt;a
href="http://www.galls.com/wav/WhelenPierce.wav"&gt;this,</a> only not
quite as fast. Maybe 500 cycles per minute, or about 8 per second.

The bike I'm buying should have separate buttons for the siren and the
air horn. I'd use the siren switch &amp; button for this stutter tone, so
that the air horn would have two different power inputs (I'd crimp
splice the inputs into one). I could probably put the thing together
myself if I knew what I needed, and it could be built on a Radio Shack
project board. Inputs and outputs would be 12 volts DC.

Any ideas or suggestions?
 
The real question here is the electrical requirements of the air horn. You
might need a rather big relay, which implies a rather slow relay -- or else
some kind of transistor switching. How much current does the horn draw?
And how does it work? That is, are we really powering an air pump?

&lt;cmhbob@adelphia.net&gt; wrote in message
news:1124774750.450684.112360@o13g2000cwo.googlegroups.com...
I ride a <a href="http://www.policemotorcycleescort.com">motorcycle&lt;/a
for a living, as a funeral escort. We're not allowed to use sirens, but
we can use air horns. We use a Whelen electronic air horn.

I'm getting my own bike--a retired CHP BMW R1100RT-P. All the CHP gear
has been stripped, which means I need to re-outfit it for escort use. I
want to tweak the air horn a bit, and get a relay that will "stutter"
the air horn, like the phaser siren sound, something like &lt;a
href="http://www.galls.com/wav/WhelenPierce.wav"&gt;this,</a> only not
quite as fast. Maybe 500 cycles per minute, or about 8 per second.

The bike I'm buying should have separate buttons for the siren and the
air horn. I'd use the siren switch &amp; button for this stutter tone, so
that the air horn would have two different power inputs (I'd crimp
splice the inputs into one). I could probably put the thing together
myself if I knew what I needed, and it could be built on a Radio Shack
project board. Inputs and outputs would be 12 volts DC.

Any ideas or suggestions?
Click to expand...
 
No, it's not an air pump, but an electronic air horn. See
http://pb.whelen.com/automotive/ProductSheets/10950.pdf. I'm using the
PAH112. It draws 8 amps at 12 VDC.
 
cmhbob@adelphia.net wrote:
I ride a <a href="http://www.policemotorcycleescort.com">motorcycle&lt;/a
for a living, as a funeral escort. We're not allowed to use sirens, but
we can use air horns. We use a Whelen electronic air horn.

I'm getting my own bike--a retired CHP BMW R1100RT-P. All the CHP gear
has been stripped, which means I need to re-outfit it for escort use. I
want to tweak the air horn a bit, and get a relay that will "stutter"
the air horn, like the phaser siren sound, something like &lt;a
href="http://www.galls.com/wav/WhelenPierce.wav"&gt;this,</a> only not
quite as fast. Maybe 500 cycles per minute, or about 8 per second.

The bike I'm buying should have separate buttons for the siren and the
air horn. I'd use the siren switch &amp; button for this stutter tone, so
that the air horn would have two different power inputs (I'd crimp
splice the inputs into one). I could probably put the thing together
myself if I knew what I needed, and it could be built on a Radio Shack
project board. Inputs and outputs would be 12 volts DC.

Any ideas or suggestions?
Click to expand...
Yes - use a power mosfet for this. Gate it on with
a 555 for the stutter, or straight from a switch for
regular horn.

Ed
 
ehsjr &lt;ehsjr@bellatlantic.net&gt; wrote:

cmhbob@adelphia.net wrote:
I ride a <a href="http://www.policemotorcycleescort.com">motorcycle&lt;/a
for a living, as a funeral escort. We're not allowed to use sirens, but
we can use air horns. We use a Whelen electronic air horn.

I'm getting my own bike--a retired CHP BMW R1100RT-P. All the CHP gear
has been stripped, which means I need to re-outfit it for escort use. I
want to tweak the air horn a bit, and get a relay that will "stutter"
the air horn, like the phaser siren sound, something like &lt;a
href="http://www.galls.com/wav/WhelenPierce.wav"&gt;this,</a> only not
quite as fast. Maybe 500 cycles per minute, or about 8 per second.

The bike I'm buying should have separate buttons for the siren and the
air horn. I'd use the siren switch &amp; button for this stutter tone, so
that the air horn would have two different power inputs (I'd crimp
splice the inputs into one). I could probably put the thing together
myself if I knew what I needed, and it could be built on a Radio Shack
project board. Inputs and outputs would be 12 volts DC.

Any ideas or suggestions?


Yes - use a power mosfet for this. Gate it on with
a 555 for the stutter, or straight from a switch for
regular horn.
Click to expand...
At one time my cars used to bristle with my DIY gadgets, but just
about all essentials have been built in for a decade or so now. The
only device in my present car my 'Granny Horn'. A foot operated
microswitch enables a low duty 555 astable which activates the
existing horn relay, delivering a series of very short (hence
'gentle') beeps. Useful not only for grannies about to step off the
curb but also in sharp bends on country lanes hiding horse riders and
ramblers.

By far the hardest part of that project was getting wires through the
bulkhead!

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
cmhbob@adelphia.net wrote:
I ride a <a href="http://www.policemotorcycleescort.com">motorcycle&lt;/a
for a living, as a funeral escort. We're not allowed to use sirens, but
we can use air horns. We use a Whelen electronic air horn.

I'm getting my own bike--a retired CHP BMW R1100RT-P. All the CHP gear
has been stripped, which means I need to re-outfit it for escort use. I
want to tweak the air horn a bit, and get a relay that will "stutter"
the air horn, like the phaser siren sound, something like &lt;a
href="http://www.galls.com/wav/WhelenPierce.wav"&gt;this,</a> only not
quite as fast. Maybe 500 cycles per minute, or about 8 per second.

The bike I'm buying should have separate buttons for the siren and the
air horn. I'd use the siren switch &amp; button for this stutter tone, so
that the air horn would have two different power inputs (I'd crimp
splice the inputs into one). I could probably put the thing together
myself if I knew what I needed, and it could be built on a Radio Shack
project board. Inputs and outputs would be 12 volts DC.

Any ideas or suggestions?
Click to expand...
Oops - meant to add:
Use 1.5K for R1 and Make R2 with a 33K in series with
a 4.7K. Use 2.2 uF for the cap. See
http://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm

Use the diagram for the Astable, about 1/2 way down the
page. The Mosfet gate goes to pin three of the 555
through a 330 ohm resistor. The source and drain go
in series with the horn and the supply, source to +,
horn between drain and minus. Add a 220K resistor from
source to gate. An SPF9Z34 will work for the Mosfet.

Ed
 
&lt;cmhbob@adelphia.net&gt; wrote in message
news:1124811861.105138.195980@f14g2000cwb.googlegroups.com...
No, it's not an air pump, but an electronic air horn. See
http://pb.whelen.com/automotive/ProductSheets/10950.pdf. I'm using the
PAH112. It draws 8 amps at 12 VDC.
Click to expand...
OK, you could use a 555 timer chip driving a power MOSFET, but make sure the
power MOSFET is rated for 10 amps or more and is on a heat sink.
 
Terry Pinnell wrote:

At one time my cars used to bristle with my DIY gadgets, but just
about all essentials have been built in for a decade or so now. The
only device in my present car my 'Granny Horn'. A foot operated
microswitch enables a low duty 555 astable which activates the
existing horn relay, delivering a series of very short (hence
'gentle') beeps. Useful not only for grannies about to step off the
curb but also in sharp bends on country lanes hiding horse riders and
ramblers.

By far the hardest part of that project was getting wires through the
bulkhead!
Click to expand...
heh - I was wrestling with that for about a half hour, trying
to cram my entire body under the dashboard to find the &amp;^$*)
existing wireing harness hole, when my neighbor came over to
ask whatinthehell was I doing, based on my disheveled appearance,
bleeding fingers, dirty shirt etc. I told him and he said "piece
of cake". The guy has a belly about the size of Nebraska - yet
he was done in under 5 minutes. He repairs cars for a living, and
was able to kneel on the ground and locate the existing bulkhead
hole by feel and stuff the wires through.

Ed
 
I read in sci.electronics.design that ehsjr &lt;ehsjr@bellatlantic.net&gt;
wrote (in &lt;bDkPe.4209$p32.1864@trndny06&gt;) about 'I think I want a
relay', on Thu, 25 Aug 2005:

I told him and he said "piece
of cake". The guy has a belly about the size of Nebraska - yet
he was done in under 5 minutes. He repairs cars for a living, and
was able to kneel on the ground and locate the existing bulkhead
hole by feel and stuff the wires through.
Click to expand...
Yes, to repair cars efficiently you need to be ambidextrous and able to
make a mental image of what you can JUST get two fingertips of your left
hand to. It helps to have had a LOT of practice.
--
Regards, John Woodgate, OOO - Own Opinions Only.
If everything has been designed, a god designed evolution by natural selection.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk
 
On Thu, 25 Aug 2005 15:49:31 +0100, John Woodgate
&lt;jmw@jmwa.demon.contraspam.yuk&gt; wrote:

I read in sci.electronics.design that ehsjr &lt;ehsjr@bellatlantic.net
wrote (in &lt;bDkPe.4209$p32.1864@trndny06&gt;) about 'I think I want a
relay', on Thu, 25 Aug 2005:

I told him and he said "piece
of cake". The guy has a belly about the size of Nebraska - yet
he was done in under 5 minutes. He repairs cars for a living, and
was able to kneel on the ground and locate the existing bulkhead
hole by feel and stuff the wires through.

Yes, to repair cars efficiently you need to be ambidextrous and able to
make a mental image of what you can JUST get two fingertips of your left
hand to. It helps to have had a LOT of practice.
Click to expand...
It always amazes me what different skills each hand is most adept at.

I'm right-handed, yet there are many things my left hand is better
at... like removing jar lids ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
 
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