Make: electronics book, Experiment number #11 part 2

Make: electronics book, Experiment number #11

Adding a bunch of component to create an alarm sound.

Alright im not going to explain everything, just to say that the size of the capacitor regulate the frequency at which the LED would flash in the first part of experiment 11.

If we use a capacitor that has a very high frequency, you'll get a constant on-off really fast which can be translated in a sound.

Get this signal to go on and off at a slower rate and you'll end up having something that sounds like an alarm.

 

Make: electronics book, Experiment number #11

Make: electronics book, Experiment number #11

Putting it all together.

In the first part of this experiment, we put together a programmable transistor with a capacitor to try and simulate the result of a previous experiment in which we used a switch.

The circuit was easy enough and the explanation pretty clear.

The result was a blinking LED.


The difference with the 2N6027 transistor compared to the 2N2222 that we used in the previous experiment is that the 2N2222 amplify the amount of current it gets in the gate, and the 2N6027 use the gate as a information to know how at what amount of current it should let the signal through.

as in:
If we put 2 volts  in the base, the anode must receive at least 2volts before the transistor let the current through.

Anyhow, this was pretty straightforward.

Here is the final result:

Make: electronics book, Experiment number #10

Make: electronics book, Experiment number #10

Transistors 101.

Alright, im still not certain about capacitors, but i decided to move forward and perhaps i'll eventually come across a satisfying explanation.

This experiment was an introduction to transistors.

Very interesting and easy to use.

The experiment was very easy and for the first time, there were no problems!!

To summe up what i learned, a smaller positive current is introduced to the base of a transistor, and it get activated and allow the bigger current to go through.

The more current is added to the base, the more current it let through.


Then the author of the book made us do something fun, remove the resistor that was limiting the current to the base of the transistor and replace it with our finger.

The current was getting through the finger, as showed in the video.

The closer the wires, the less resistance and the more the transistor was letting current through so the led was getting brighter.

All fun and games until i read the warning "don't use two fingers since it will let the current go through your body and it is dangerous" which i had been doing for the last 2 minutes.

A mistake from my part but this raised a question, why was the led so bright when i let the current go through my entire body? shouldn't the resistance offered by my whole body be pretty big?


Anyhow this was a fun experiment.


Looking forward to the next one!

Make: electronics book, Experiment number #9

Make: electronics book, Experiment number #9

Measuring the voltage accumulating on a capacitor.

Connect the circuit (a pushbutton, a resistor and a capacitor).
Connect the probe of the meter to the capacitor,
See the voltage rise (and drop when you shut down the power.)

Sounded pretty simple but a few problems arose.

First of all I couldn't get any voltage on the emter to begin with.
So I changed the capacitor and it seemed to work.

Secondly, I eventually read in the book that the voltage in the capacitor should eventually reach the same voltage as the source.
My dc adaptor was set to 12V but i was reading about 17.5 Volts from my capacitor.
What the hell was going on?

After a small head ache, i realize that simply, my dc adaptor is faulty and give me voltage much higher than what it suppose to.

I guess i'll try to send it back to the electronics store.


Thats it for this experience, after the experience, re-reading the chapter on capacitor in both the Make: electronics book, and the "for dummies" book, plus watching the make youtube video, i have a better understanding of capacitors but still have a question about experiment number 8 that i cannot find the answer for.
(why the doesn't the circuit just ignore the capacitor, since there is no resistance in the relay so it is just like a direct wire. So you should have a result exactly similar to the same circuit without a capacitor.
Also since the circuit clearly doesn't ignore the capacitor, and presumably, the relay coil only use the power from the capacitor and nothing from the power supply, why does the capacitor get all of the voltage?)

if anyone can explain this to me, i would be very grateful!


Thank you!

Make: electronics book, Experiment number #8

Make: electronics book, Experiment number #8

In this experiment, we are adding a capacitor to the experiment #7 circuit.

Everything worked great.

Although i had problems makinf this work at first, im not certain why but the circuit wasn't working and a burn smell was starting to appear.

I changed the capacitor and play around and finally it started to work.

I'm still not sure what was the problem.

So everything is working fine.

My only question is why did we add the capacitor in parallell instead of in series.
if anyone can explain me this it would be great!

Another thing is i don't fully understand the "capacitors have infinite resistance" things and exactly how they work or what use they could have.

I guess i'll find out later in the book.

UPDATE:

after re-reading the chapter on capacitor in both the Make: electronics book, and the "for dummies" book, plus watching the Make youtube video, i have a better understanding of capacitors but still have a question about experiment number 8 that i cannot find the answer for.

Why the circuit doesn't just ignore the capacitor, since there is no resistance in the relay so it is just like a direct wire. So you should have a result exactly similar to the same circuit without a capacitor.
Also since the circuit clearly doesn't ignore the capacitor, and presumably, the relay coil only use the power from the capacitor and nothing from the power supply,
- why does the capacitor get all of the voltage and the relay's coil get nothing from the power supply?


if anyone can explain this to me, i would be very grateful!




Thank you!

Make: electronics book, Experiment number #7

Make: electronics book, Experiment number #7

Relays.

So in this experiment, we are learning about relays.
(non latching relays which is a good thing because the latching relay was one of the components I couldn't find at the store.)

The first part of the experiment was to open up the tiny relay by shaving the plastic box covering it with a utility knife.

The inside of my relay turn out to look nothing like the ones show in the pictures in the Make: electronics book.
Which in turn turn out not to be important at all since i could clearly see the mechanism working and understanding the mechanic of it.


The next part of the experiment was to setup a circuit with a 12 Volts power supply that would light up some leds.

The circuit was easy enough to setup but it wasn't working right.
The result was supposed to be that when i press the button, the second led should light up but that wasn't working.

The mechanism of the relay was working since i could see the little plates going up and down but the other relay just wouldn't light up.
Changing the relay didn't change anything so i decided to google the component model to see if i could get more info from the manufacturer.
I found the info sheet but it wasnt very useful for me.

In the end i move the connections around and i finally hit the jackpot and got it to run properly.

Once i figured out where things were supposed to be connected on the relay, everything went smoothly.

pretty cool experiment for sure.

Im behind with the blogging, i've finished a couple more experiment and i need to write them down.
This take longer than i thought.

until next time

Make: electronics book,, setting up the dc adapter

Make: electronics book,, setting up the dc adapter

Before the next experiment, we had to set up the DC adapter so we can use it for our circuits.

I didn't foresee any problems until I cut the little head off.

To my surprise, there was only one wire, and a bunch of little hair wires around it.
Turn out that the little hair wires were the ground, and the wire (which contained a bunch of little hair wires wrapped in some isolation) was the positive.

So i thought there was no way to use this without soldering proper wires to it.
So we did (I still haven't bought the helping hand gadget, so my wife helped me out)
Note to self: buy that helping hand gadget, very very useful!!

So 10 minutes later, a little burn on my finger and a wife worried for my safety when im doing electronics and i have the adapter ready to go.

Soldered wires

Taped and ready to go

All done, ready for the next experiment!

Make: electronics book, Experiment number #5

Make: electronics book, Experiment number #5

I could only do one experiment yesterday.

Due to spending all of my free time buying some kind of tool box at Canadian tire with tiny compartments and sorting all of the tiny components in it all day.

What an enormous pain that was!

After all of the work required to make the list of components needed for the experiments in the book,
- go to an electronics store and buy the components and tools (many hours)
- buy some kind of tool box with compartments
- sort out all of the components in the tool box (some of them i cannot sort since i have no idea what they are)
I can confidently say that you are much better off buying the kits (kit 1 - kit 2) after all.
If you are an adult with a job, this is 2 full day of work that you need to invest.
An entire weekend.
I guess if you are a student and have plenty of time on your hand, you can buy all of that stuff yourself but it just doesn't worth it otherwise.

Also it turned out to have been much more expansive to buy all of that stuff myself.
I didn't make proper calculation but after buying everything, i think i'm in pretty close to $400 and buying the tools and kits from Maker SHED would have been about $300.
AND I'm still missing pieces and some of them are probably the wrong ones.


Anyhow, the experiment itself was fine.

Connecting 2 SPDT together and understanding the switching...
(learning what things like SPDT mean ;) )

I realize i only had 1 SPDT big enough to put wires on.

I had a second one but it was very small, so we tried (me and my wife) to solder some wires to it.
I ended up breaking the thing in the process... bummer.

I was putting my things away ready to give up for the day when i realize i had a tiny slider switch, which is a SPDT as well just with a slider instead of a arm.

So instead of doing the same mistake and destroying the thing trying to solder wires to it, I took out the breadboard and with the switch with it.
(thankfully, my breadboard knowledge is still good after so many years since college.)

Nothing too crazy, just wiring the circuit and testing it.
It was fun but too bad i couldn't do any more experiments.

I have the feeling this book will end up taking longer than i thought...

Make:electronics book, Experiment number #4

Make: electronics book, Experiment number #4

Okay so this experiment was about connecting a LED with a battery pack and a resistor.

It was very easy.
I tried a week ago with the wrong potentiometer, a tiny one, and it was a pain to connect and turn the knob. This time i had a nice big one and everything went smoothly!

The author of the Make: electronics book made us measure voltage across the potentiometer while we were adjusting the potentiometer and see the result in the change of voltage.
(the more resistance the more voltage it would seem.)
Also made us measure current
The more resistance the least current can go through.
V = R x I
6V = 1k x 6 Amp
6V = 2k x 3 Amp
6V = 4k x 1.5 Amp

I = V/R
R = V/I

(After reading the electronics for dummies, and the chapter on ohms law in the Make: electronics book, i'm getting pretty familiar with Ohm's law!)

Anyway it was fun to blow 2 LEDS, and my wife seemed to enjoy the experiment as well.

I must say that the flexible alligator grip wires that i was using made this much easier.
If you buy the Make: electronics book, you may want to invest in 3-4 of those.

Dim LED

Brighter LED

Only one experiment today, hopefully when i sit down to do some of this stuff next time i will be able to get through many in one sitting.

This was a long day and i must watch the end of LOTR :)