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midland 18 str weather radio strobe light

Posted: Wed Apr 11, 2012 11:44 am
by moe
Has anyone ever looked as to what is in the Midland model 18 STR Strobe light that is used in the weather radios?
I see these lights for around $15.00 plus shipping but a close look of the photo 3 LED's
I would like to try and build a light for my weather radio
Thanks
Moe
http://www.amazon.com/dp/B0002UB2K0/?ta ... 5lq3mh3j_e

Re: midland 18 str weather radio strobe light

Posted: Thu Apr 12, 2012 2:50 pm
by dacflyer
looks like leds in series,
my weather radio has the same thing..i'll check into it more for you...
i am sure when the radio goes off..the output goes high.. 9V output i think..possibly flashing.

Re: midland 18 str weather radio strobe light

Posted: Thu Apr 12, 2012 5:02 pm
by Janitor Tzap
dacflyer wrote:looks like leds in series,
my weather radio has the same thing..i'll check into it more for you...
i am sure when the radio goes off..the output goes high.. 9V output i think..possibly flashing.
Your weather radio has a test button right?
Well....
The Plug Jack looks too be 1/8.
So get a 1/8 plug and stick it in to the flash option jack on the weather radio.
Put a 9Vdc Analog Volt Meter on too the 1/8 plug connections, and press the test button.
If the meters needle pulses up and down.
Then I say the Led's are driven by an internal flasher circuit in the weather radio.
If it is a steady voltage, then the flasher circuit is built into the LED package.

Note: Most auto-ranging DMM's aren't fast enough to handle a very fast voltage change {flash rate}.
Thus, if you have an older d'Arsonval movement VOM.
It can more readily see the pulsing voltage.


Signed: Janitor Tzap

Re: midland 18 str weather radio strobe light

Posted: Tue Apr 17, 2012 12:57 pm
by dacflyer
ok, here is what i have found out...
i have the midland weather radio WR-300
the radio has a siren test button, but it will not activate the strobe. the strobe will only be activated when the radio actually goes off..
also. there is no power that comes from the strobe outlet...
the strobe outlet is only a switched output. no power output at all..
the strobe is battery powered. ( 18-STR )
i have a bicycle led light that looks exactly the same, has 2 AA batterys..
i actually changed the leds in it to brighter ones :D
so i am sure you could modify something.
i called MIDLAND they could not tell me the rated load of the strobe outlet.
they only told me that it is a switched output.

good luck...

Re: midland 18 str weather radio strobe light

Posted: Tue Apr 17, 2012 1:31 pm
by moe
Thanks I will look into it, I also have a light that looks like the photo will try to wire it to a 1/8 inch plug and see it it works

Re: midland 18 str weather radio strobe light

Posted: Tue Apr 17, 2012 8:00 pm
by dacflyer
ya, just wire the cord between B+ and the led +
let me know how it goes for ya :)

Re: midland 18 str weather radio strobe light

Posted: Wed Apr 25, 2012 11:12 am
by moe
just a up date wired the light as we talked about to a 1/8 inch plug. When I short the pins on the plug the light will come on.But when I plug it into the radio the light goes on about half as bright with no alarm.If I trip the alarm the light is bright. Any ideas ?
Thanks
Moe

Re: midland 18 str weather radio strobe light

Posted: Wed Apr 25, 2012 4:10 pm
by dacflyer
try to reverse the polarity on the plug...might be leaking backwards thru the transistor
and are you using neg from battery or pos from battery?

try both and reversing polarity on the plug..
either way i am sure its a miswiring of some sorts..

let us know.. ;)

Re: midland 18 str weather radio strobe light

Posted: Mon Apr 30, 2012 11:51 am
by moe
:razz: dacflyer
That did it that for your help it works great total cost $4.00
:grin: moe :grin:

Re: midland 18 str weather radio strobe light

Posted: Mon Apr 30, 2012 5:29 pm
by dacflyer
cool deal, how did you wind up wiring it ?

Re: midland 18 str weather radio strobe light

Posted: Mon Apr 30, 2012 7:18 pm
by moe
I reversed the polarity on the plug as you said never thought of that thinking it was more like a switch
Thanks again

Re: midland 18 str weather radio strobe light

Posted: Thu May 03, 2012 11:17 am
by dacflyer
ok,, so the POS from your battery went to the tip and load to the gnd. part of the plug ?

Re: midland 18 str weather radio strobe light

Posted: Thu May 03, 2012 11:48 am
by moe
Yes

Re: midland 18 str weather radio strobe light

Posted: Thu May 03, 2012 2:25 pm
by dacflyer
ok, cool...