MAKE: Electronics Ex. 10 Help Needed

[nyancatvsghosthead]

Alright, so I used my brain a TON!!! Here is everything I've tried:

1.

2.

3.

4.

5.

6.

7.

That's everything I've tried. I thought that based on the last one that would work because in the last one, all I had to do was connect the wires so that it fit. That was not the case here. May I please have some help? Thank you.

 

[nyancatvsghosthead]

I also tried two other things. I think that is all has to connect I think that I'm totally doing this wrong though. I ran out of ideas and turned to this. Thank you so much for helping. I hope I'm fit to do electronics. I feel kind of like I'm not but I'll keep trying anyways ;(... Anyways, I hope I can make this work. Thank you. Also, if you think there's a hint you could give that just sends me in the right direction, I think that will work better than just giving me the answer because I want to figure some of it out, so that I understand the experiment. Thank you.

 

[(*steve*)]

It's really hard to see what you've tried because you don't tell us.

You also don't link to the circuit diagram

You also don't give us any way of interpreting the polarity or voltage from your power supply.

You also don't give us a clear shot of a transistor which I think is under there somewhere, nor of its connections or even part number.

Without any of that we're really not going to be able to help.

How about you address all of those for us and we should be able to give you some good advice.

 

[davenn]

Also just as a big hint for the benefit of others

resize you pics before posting say to a max of 700x500 rather than 2100 x 2800

its makes them much easier for us to view and faster for you to upload and us to download

cheers
Dave

 

[timothy48342]

It is very hard to see how things are connected in these images.

In the last image, you can see part of the transister and it might be on rows 3, 4, and 5. (Not sure)

I think this circuit is what was intended. (By the way, it took me about 5 minutes to create this. I used "CircuitMaker Student". It is circuit simulation software and there are plenty of different programs out there. This is only the second program I tried. I mostly just use it to draw and the export-circuit-as-graphic feature works great. I open the bitmap with Windows Paint and save it in monochrome and the file is very small. Just google "circuitmaker student" or "circuit simulation software")

That's definately not how you have it connected, though. I see you you have a green wire connected in hole numer "A8". That's not connected to anything because B8, C8, D8, and E8 are empty, so that wire is not doing anything.
And I see you have one end of a resistor in hole number "A6" that is not connected to anything either.

I might be good to take a look at how the breadboard is connected on it's inside:

(If that image doesn't show up, this is the page it came from:
http://cheapbots.wordpress.com/2006/10/22/about-breadboard/)
Edit:Found an even better image that shows the inside connections of a breadboard:

:endEdit
Also, tell us how the circuit is supposed to work. (I know the LED will light up, but tell us HOW so that we can help you figure it out on your own.)

--tim

...
resize you pics before posting say to a max of 700x500 rather than 2100 x 2800
...

I was wondering exactly that. So far, I've been limiting myself to tiny monochrome images, because I didn't know what size would be good. Thank you, Dave.

 

[KJ6EAD]

I thought you guys liked 15 Megapixel images so you could zoom in and see everything in clear detail.

 

[davenn]

to the original poster....

after some resizing of this pic.... some comments...

it would really help lots if you used red for positive Volts and black for negative from
the power supply. 2 reasons...
1) you can then be sure YOU havent reversed connections
2) We can clearly see that as well

At the moment you have 2 greys going into 2 greens we cannot see the PSU (battery) so we have no idea if you have the polarity correct or not

Its a bit hard to tell if you have the transistor connected correctly the pins for it are hidden by that 680 Ohm resistor
Note the info Timothy has given on the way the breadboard is wired and you will see that that small and large green wire loops going up the outside are not needed

cheers
Dave

 

[nyancatvsghosthead]

The power supply is connected to the wall. It is 1.5 volts.

Here is what the book says the circuit is supposed to look like:

Here is a picture of my circuit with a better view of the transistor. It is part 2N2222:

 

[(*steve*)]

OK, 1.5V isn't going to work because the LED required a higher voltage than that to operate.

You still haven't posted all that I need, but I assume that the description that you have partially photographed mentions a voltage that is significantly higher than 1.5V

 

[KJ6EAD]

The book indicates a 12V supply and the component values are consistent with that.

 

[timothy48342]

Hey, just found out that this book is online:
http://my.safaribooksonline.com/boo...asics-and-more/experiment_10_transistor_switc

So this helps.

I notice that the switch (SW1) is not hooked up in any of the pictures.

As far as the voltage... If you don't have access to exactly 12V, what do you have available?

--tim

 

[jackorocko]

1.5V? Yeah that will never work. You will need to come up with 12V supply or as KJ hinted at, change the value of the components to work with a 9V battery supply.

 

[nyancatvsghosthead]

Alright, I set it to 12V but it doesn't work. What now?

 

[nyancatvsghosthead]

Also, do I have to hook up the switch? I moved the switch next to the wire and the R2 connection. I would think that that would connect them, other than it didn't. I think though that maybe it doesn't matter. Does the transistor have to hook up to anything? Should I keep the connection from the transistor to R2 and R1 and do either of those need to be taken out if so? I've always thought that it has to do with the connections with the wires. Anything here I'm still doing wrong?

 

[timothy48342]

Can you tell which is the + and which is the - on your power source? That is one thing we could not tell from the pictures.

And did you plug in the switch in holes C6 and C8? (S1)

Tell us everything. Don't assume we know.

-tim
Edit: Opps. I posted at the same time as you. Let me read yours. Will post again in a sec. :endEdit

 

[nyancatvsghosthead]

Supposedly, this is how it works:

1. Through R1 voltage reaches the collector of the transistor
2. the transistor only lets a little bit of voltage trickle down, so the LED stays dark
3. When the button is pressed, voltage is applied through the separate path to the base
4. This tells the transistor to open its solid state and let current go through the emitter
5. the current goes through R3

That's how it works. I tried to put it into my own words to make sure I understand it.

 

[timothy48342]

Also, do I have to hook up the switch? I moved the switch next to the wire and the R2 connection. I would think that that would connect them, other than it didn't. I think though that maybe it doesn't matter. Does the transistor have to hook up to anything? Should I keep the connection from the transistor to R2 and R1 and do either of those need to be taken out if so? I've always thought that it has to do with the connections with the wires. Anything here I'm still doing wrong?

Connect the switch? Yes.

Switch location? As in the picture. Next to R2. (hole C6) and the other end in C8.

It didn't connect them? You do have to press the switch also.

The transister connections? I think you have the transister where it needs to be. You have it on rows 3, 4, and 5 in the right-hand side, so it is connected to anything else in those 3 rows. It is connected to R1, R2, and R3. (At least it was) You could post a new pic. If you do post a pic, bend back the longer components like you did the last time, so we can see every connection. (I don't care one bit about the file size. I do like to be able to zoom in close.)

R2 and R1? I would not take them out. You had all the connections very close to working in your last picture. The 1.5V power source was a problem.

You have always thought it was the connections with the wires? I see that. I see that you tried to make extra connections with the green wires. I maybe just may have been your power source that was the problem.

So make sure that switch is connected like in the book and press the button.

Not working? Post another pic, please.

Good work, so far.

--tim

 

[timothy48342]

Supposedly, this is how it works:

1. Through R1 voltage reaches the collector of the transistor
2. the transistor only lets a little bit of voltage trickle down, so the LED stays dark
3. When the button is pressed, voltage is applied through the separate path to the base
4. This tells the transistor to open its solid state and let current go through the emitter
5. the current goes through R3

That's how it works. I tried to put it into my own words to make sure I understand it.

You got it dead on!!! That is exactly how it works. (And good that you put it in your own words. That's important.)

Read my last post. Check the switch. Press it. Post a pic.
-t

 

[(*steve*)]

Supposedly, this is how it works:

1. Through R1 voltage reaches the collector of the transistor
2. the transistor only lets a little bit of voltage trickle down, so the LED stays dark
3. When the button is pressed, voltage is applied through the separate path to the base
4. This tells the transistor to open its solid state and let current go through the emitter
5. the current goes through R3

That's how it works. I tried to put it into my own words to make sure I understand it.

Let me rewrite some of it a little for you:

2) with no base current, only a very small leakage current flows between the collector and the emitter (effectively none) and it is not enough to light the LED.

3) when the button is pressed, current can flow into the base of the transistor

4) the small base current allows a larger current to flow between collector and emitter

 

[nyancatvsghosthead]

Here are a few of the things I've tried:

The last experiment went perfectly, so I think that I can make this one work. Hopefully this will help? Thanks for the advice.