Motion Activated Noise

[twizfire]

I started looking at electronics for the first time yesterday. My training includes Welcome to the Electronics Club and Kipkay Videos. In otherwords, I know everything there is to know and am just asking these questions to test you.
My friend wants a buffalo's head to "moo" when some one walks by. I found this 9V Recording Module and this PIR Sensor Module. You can remove the play button and solder on your own.
Would I be able to connect the two components with a relay using it as the play button? Is just a relay enough?
5V relays seem to be common but some one said the PIR only puts out 3.3V. Will this still work? Do I need to find a 3.3V relay or try to increase the voltage?
The 2 modules use different power. PIR 5V and Recording Module 9V. Can I hook them up to the same 9V power supply in parallel and use resistors to bring down the voltage on the PIR without affecting the voltage on the Recording Module?

Thanks in advance for any help.

 

[Reloadron]

I would likely use a 7805 5 volt regulator to get my 5 volts (from 9 volts) to power the PIR sensor. I would then have the PIR sensor output drive a transistor like a cheap everyday 2N2222 and use the transistor to drive the relay used to trigger the audio module.

There are other ways to go about it and likely someone else has some thoughts but I would likely approach it as I mentioned.

Ron

 

[twizfire]

So is this right? Capture.JPG - Windows Live
Not sure if I picked the right icons so I labeled them too.

EDIT: The relay should be Normally Open though...I think.

 

[twizfire]

My power source will actually be 12V. I should still be able to use the 7805 for the 5V side and a 7809 for the 9V side...right?

 

[canadaelk]

So twizfire, let me get this straight: you started looking at electronics for the first time yesterday and you know everything there is to know. Mate, your words, not mine. Welcome to the club of RS consultants. It used to take them 4 weeks of training! E

 

[twizfire]

It's been 2 days now so you know I even got all the equations and codes memorized.

Now if only I could do electronics like I could talk out my ass, maybe I'd have this project finished. I think I have a while though because next I have to teach myself to solder.

 

[canadaelk]

Hey twizfire - I spent all day studying brain surgery, so whenever you are ready for your surgery, just let me know. Happy to help! E

 

[twizfire]

I need lung surgery. I'll give you another day.

 

[twizfire]

Taking a closer look at the Recording Module, I found that there is a 5V regulator on it already. I can bypass the regulator and put 5V directly into it. Does that mean my new setup would be Capture.JPG - Windows Live ?

 

[Reloadron]

You may have a problem here in that the recording module actually needs 9 volts. Since the module has a 5 volt regulator depending on the regulator used you would need to supply a few volts greater than 5 volts. For example if we apply 5 volts to a regulator like the 7805 we get nothing out, we need to apply at least 7 volts before the regulator will work. Just something to consider.

Ron

 

[HarveyH42]

You may have a problem here in that the recording module actually needs 9 volts. Since the module has a 5 volt regulator depending on the regulator used you would need to supply a few volts greater than 5 volts. For example if we apply 5 volts to a regulator like the 7805 we get nothing out, we need to apply at least 7 volts before the regulator will work. Just something to consider.

Ron

Are you sure? I always thought those regulators just passed everything through, below the cutoff. Didn't know they shut everything down, when they drop out. Good to know, does this work the same for the LM317?

As far as the origional post... You realize that for under $10 at most any 'Dollar' type store, you can already pick up a motion trigger animal, even a cow? Range is about 3 feet though, but works out, not real loud either...

 

[twizfire]

Yes, but I enjoy learning new things. I'm a computer geek and I love to build mod computers. I figured learning how to play with some circuits would help me do some new, cool things with computers.

 

[Reloadron]

Are you sure? I always thought those regulators just passed everything through, below the cutoff. Didn't know they shut everything down, when they drop out. Good to know, does this work the same for the LM317?

As far as the origional post... You realize that for under $10 at most any 'Dollar' type store, you can already pick up a motion trigger animal, even a cow? Range is about 3 feet though, but works out, not real loud either...

Yes, it is called the "Dropout Voltage"

All linear regulators require an input voltage at least some minimum amount higher than the desired output voltage. That minimum amount is called the drop-out voltage. For example, a common regulator such as the 7805 has an output voltage of 5V, but can only maintain this if the input voltage remains above about 7V. Its drop-out voltage is therefore 7V - 5V = 2V. When the supply voltage is less than about 2V above the desired output voltage, as is the case in low-voltage microprocessor power supplies, so-called low dropout regulators (LDOs) must be used.

The above taken from here.

I just used the LM7805 as an example where 7 volts is required to have it work. There are linear regulators that have lower dropout voltages but all have a dropout voltage.

Douglas Fir is this little LED Christmas Tree we have with a sensor. Years ago a few bucks at the dollar store. I put it out around the holidays just to freak out the dogs. It talks and sings.

Ron

 

[HarveyH42]

Yes, it is called the "Dropout Voltage"



The above taken from here.

I just used the LM7805 as an example where 7 volts is required to have it work. There are linear regulators that have lower dropout voltages but all have a dropout voltage.

Douglas Fir is this little LED Christmas Tree we have with a sensor. Years ago a few bucks at the dollar store. I put it out around the holidays just to freak out the dogs. It talks and sings.

Ron

I was just under the impression that the regulation part stops working, but you still get voltage out, not zero voltage output. Could be slightly higher or lower than the 5 volts expected from the 7805.

My mom has a zoo around her pool, my dog is too freaked out to go swimming. Pretty weird too, he doesn't touch them, peed on the frog once though...

 

[twizfire]

I'm buying the parts from www.jameco.com today but I'm not sure what relay I need to get. Any one willing to browse the site real quick and give me advice or just a link to one that should work?
I get that I need a 5 volt SPST relay (though I can use one with whatever poles and throws the rest would just be wasted). There's a lot of other stuff I still don't understand even though my first post may have fooled you. Most of them list the Ohm and the Amp but I don't understand how to include that into my circuit yet or what it means for the relay I purchase.
ALSO, since I don't feel like I've asked for enough help on this tiny project, I'm looking for more sites that have good info on this electrical stuff. I've gotten a lot of good information from the electronics club but there's only so many times you can read through a site before you've picked up everything you are going to.

Thanks in Advance

Edit: https://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1860088_-1 ?

 

[twizfire]

In the words of The Trashcan Man, Bumpty Bump.

 

[Reloadron]

OK, so where are you at with this? What do you have and what is the plan?

Ron

 

[twizfire]

I just wanted to make sure I was picking out the right relay and if you could suggest some informative sites on electronics, I would much appreciate you.
I ordered all the stuff today and it should be here in a week. I can order a different one though if mine won't work. The link in the quote is the relay I chose.

I'm buying the parts from www.jameco.com today but I'm not sure what relay I need to get. Any one willing to browse the site real quick and give me advice or just a link to one that should work?
I get that I need a 5 volt SPST relay (though I can use one with whatever poles and throws the rest would just be wasted). There's a lot of other stuff I still don't understand even though my first post may have fooled you. Most of them list the Ohm and the Amp but I don't understand how to include that into my circuit yet or what it means for the relay I purchase.
ALSO, since I don't feel like I've asked for enough help on this tiny project, I'm looking for more sites that have good info on this electrical stuff. I've gotten a lot of good information from the electronics club but there's only so many times you can read through a site before you've picked up everything you are going to.

Thanks in Advance

Edit: https://www.jameco.com/webapp/wcs/st...001_1860088_-1 ?

 

[twizfire]

I spent all weekend reading about the transistor. This is what I have but it just doesn't seem right. Porbably because I still don't understand the jargon or because I'm wrong. Either way, thanks for the help.
We have a Base, a Collector, and an Emittor. My PIR would output to the Emittor. Collector would output to the Relay. I have no clue what Base would do, Ground maybe?

Thanks in advance.

 

[twizfire]

So what've I got right and wrong here. Obviously "?" is not a standard electronics symbol. I know the transistor goes there but not sure how.