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1  Using Arduino / General Electronics / transistor (2N2222) dropping 15v to 2v?!?! on: May 29, 2011, 02:00:09 am
I've got a PIR sensor triggering a solenoid via arduino and a 2N2222 transistor.  I'm running 15v into the circuit, but am only getting around 2v at the solenoid.  I'm a n00b and could definately use some help in figuring out what transistor I need.  I was advised to replace the 2N2222 with a relay, but the relay switches too slow.


also, the 2N2222 gets REALLY hot, so i'm quite sure i'm losing a ton of voltage to it.
2  Using Arduino / Project Guidance / PIR triggering pattern for Solenoid to actuate on: May 02, 2011, 05:34:37 pm

Extreme n00bie, here.  I am a designer in Chicago and need to get this thing project done by June 20th or I lose about $150,000 in Grad School Money. (long story).

The jist.

I need a PIR sensor, when it detects movement, to trigger a programmed pattern for a push-style solenoid to play.  Basically, I need the solenoid to play a basic beat or rhythm for 60 seconds when someone moves past the sensor. 

Also, if completed in time, this project may be funded and installed (up to 50 of these things) locally on abandoned infrastructure in the Chicagoland area, so it's power source must be some kind of battery array.  I would prefer solar, but I don't think that's feasible. 


    I'm thinking this solenoid: (
            *probably having to run at least 12v
     This PIR sensor: (

    I want the solenoid to play a pattern that is a cross between ( ) and something like this ( )

     Remember, this thing has got to be on an abandoned train line (or someplace similar) so I can't have a computer running abelton attached to it.

What I need to know:
      I need to know if I need a power driver shield for the arduino.
      Should I get my hands on a MidiTron? If so, what type of circuit configuration/arduino programming do I need in order to get this thing to play a pattern when the PIR sensor detects motion?

Sorry for all the clearly nubile questions, I just need to get this thing going and I'm startin to get THE FEAR.

attached: are images of this THING as it will appear on a streetpole or power pole.  The solenoid pushes the (blue) arm to strike the pole like a hammer on a piano strikes a string.
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