work around? 200ma limit don't want to fry it.
What would you suggest for 12vdc
These will be on 2 seperate uno r3 units.
New to uno, want to get started, see a lot of potential for its uses.
Thank you
Give us a full picture. What are your other "loads".
Maybe you can you can power them separately.
Leo..
I would like to use an uno r3, pir circuit; with piezo buzzer.
I Want to replace the buzzer with an 12vdc 300ma siren/strobe ( it is a lot louder ).
hopefully siren to be about 30-50 feet away.
Thanks for any insight.
I Want to replace the buzzer with an 12vdc 300ma siren/strobe ( it is a lot louder ).
hopefully siren to be about 30-50 feet away.
The Arduino chip runs off 5V and you can't get more than 5 out of it. And, you can only get 40mA from an I/O pin.
[u]Here is an example[/u] of a transistor driving a solenoid. Assuming your load is non-inductive (not a motor or solenoid), you can leave out the diode.
Thank you for your response and example.
So if I have this right?
What I need is a Diode 1N4004, and a solenoid L1 of some sort, a resistor or two, and a tip102 with heat sink?
And that should be capable of power either the 300mA or 400mA/ for the two separate circuits?
My mistake, I thought you could plug in a wallwart to the uno 9-12vjack?
Thank you,
The Arduino can run straight from the 12volt supply, connected to the DC jack.
An Arduino pin can drive a transistor that switches a buzzer/horn/siren/solenoid/relay/motor etc.
The circuit that DVDdoug gave you works for all of these things.
Just replace the solenoid in that picture for your siren/strobe.
Draw a picture of your final setup, and post it.
Leo..
Hi all,
Thank you in advance for the help.
Here is the drawing. I've made the notes for me as well as others.
Please feel free to offer any additional notes, tips, does and don'ts for this.
Thanks again!
So the MUR340 is a blocking diode,
Could I use this 1N5822G Rectifier Diode, General Purpose, Single, 40 V, 3 A, 525 mV, 80 A, 125 °C
Thanks,
Drawing is wrong.
The negative of the siren/strobe goes to the collector , not to ground.
The transistor switches the negative lead of the siren to ground.
Emitter of the transistor connects to supply ground and Arduino ground.
The diode goes across the siren.
The diode kills the (potentially destructive) stored energy in the coil/siren when the transistor turns off.
Any GP diode will do, e.g. a 1N4004.
Look at this picture.
Imagine the coil is the siren.
Leo..
Leo,
Thanks for responding
Glad I posted pic., just trying to get a handle on it.
Your clarifications make it easier to understand on this first one.
put new pic up.
Thanks,
Jack
Weird collector line, but basically ok.
Leo..
Sorry for weird collector line drawing.
I'll will be ordering the parts today.
Thank You!
J
Is there any reason why I can’t locate the siren,
a distance of approx. 35 feet away from the collector side of 1N4004, and the uno?
Is there distance limit?
Thank you
Just use decent wiring to minimize voltage loss over the resistance of the length of wire.
Jack771:
Leo,Thanks for responding
Glad I posted pic., just trying to get a handle on it.
Despite what Wawa says that circuit is still wrong.
That weird looking line from the collector appears to go to the -ve of the 12V supply.
The solenoid goes between the collector and the +12V supply, the diode goes across the solenoid. The -ve of the 12V supply goes to the emitter of the transistor.
Is the PIR's Vcc 5V, what is this, an input or an output?
Yes, 5V
Loaded new image, stripped down to what I had in mind at first.
All help is appreciated! still new obviously! sorry.
don't want to burn the house down, or fry stuff needlessly.
Thank you.
If you have a 12V source, the easiest way to control is with a transistor, like this.
The diode is needed to prevent the voice coil of the siren from destroying the transistor.
(When the transistor stops driving, the coil tries to keep current flowing briefly, which can create a big voltage spike that can damage the transistor. The diode lets the spike dissipate in the coil).
Jack771:
Yes, 5VLoaded new image, stripped down to what I had in mind at first.
All help is appreciated! still new obviously! sorry.
don't want to burn the house down, or fry stuff needlessly.
That diagram is still wrong, you need the transistor like CrossRoads showed you.
Thank you both for the additional info.
I think the diode, alarm, and tip102 are correct.
I hope this is better, still a bit uncertain on uno?
any changes I need? Top 12V to? Sorry!
Thanks.
J
any changes I need?
No looks right.
Top 12V to?
Nowhere, it can be removed from the diagram, or just left as a label to make the diagram look more clear.
