Getting into Electronics

oh dang

Im looking for some material to get to know electronics better. I notice there is afew kits out there, and i think that would be the best way to go for me, I learn better by experience. But i dont want to be suckered into a $80-$100 kit and it being worthless. Im wondering if you guys have any good ones you've used or think would be beneficial for me. I'd like to keep the price range at $50-$60, but am willing to go higher possibly.

Yori

This kit is the one I have. It has quite a bit in it (Over 130 parts, but they are counting the big mess of resistors you get, still quite a bit). It has some simple projects, and more projects can be found on sites such as Instructables or a google search.

I made a similar topic not too long ago, here.

oh dang

Ah thanks, i searched the forum i guess not good though.

oh dang

I ordered that kit mainly for all the small parts. But i also went to RS and picked up the parts to build a 5v power supply for a breadboard. When i got home i noticed i picked up a ML7805 regulator rather then the LM7805 that was on the sheet list. I looked it up and couldnt really find the difference or if i could go ahead and use this one. Also i picked up a 100uf capacitor rather then a 100nf. I went back for both of these neither was at RS, but its it possible to use a 0.1uf capacitor in place of the 100nf?

Yori

No idea, but the kit tells you how to make a 5v power supply for your breadboard using the parts in the kit, and a 9v battery you provide (I'm not sure what the regulator is rated, I think it can accept up to 12v).

EDIT: A quick google search for farad conversion gave me UnitConversion.org, which shows that 100nf (nano farads) is equal to .1uf (micro farads). So, they should be interchangeable. I couldn't find anything on an ML7805 regulator, but here's the data on the LM7805.

oh dang

Hmm...all the data looks the same, now i just need a .1uf and ill get it all together and test it out.

jfkfhhfj

I always have to give a plug for my blog in these threads :P

Circuits:
http://mcuplace.com/mcu/blog5.php
MCUs:
http://mcuplace.com/mcu/blog4.php

The latest post in my circuitry blog goes over your 5v PSU

oh dang

Awesome, im going to have to read over that, i made mine but it dosnt work, so im gonna have to debug it in the morning.

Yori

How do you have it wired? Post a picture if you can.

oh dang

None of the solder is touching that shouldnt be on the bottom. I might have the wrong resistor wired to the LED ..could that cause it not to work.

Yori

What value resistor are you using with what color LED? And if I'd known you'd wanted to make a 5v power supply like that, I would've linked to an instructable for one. I noticed you're using a RadioShack board, so just a random link to the RadioShack Adjustable Breadboard Power Supply. I've got a few more pulled up, if that one seems a bit too large.

BTW, where did you get the design for the power supply you made?

oh dang

I did see that one but thought it was to big. The design of mine i believe was on that site as well. Ill get a link in min.

http://images.google.com/imgres?imgu...a%3DN%26um%3D1

The only thing i did that was dif was i put in a jumper for the on/off switch.

Yori

It looks kinda like the 5v Breadboard Mini PSU, except you replaced the switch with a jumper.

oh dang

Yeap, thats exactly what i did. Im pretty sure i have the wrong resistor on it, im gonna check it out tomorrow if i get afew hours to spare.

jfkfhhfj

Now just because the LED isn't lighting, doesn't mean its "not working". An LED is essentially a Diode, so that means its polarized, which means if its backwards it wont light. You need to use a volt-meter to check whether the regulator is working.

This design is really trivial, its a positive voltage regulators. All voltage regulators (non-adjustable) usually have 3 pins, Voltage-In, Voltage-Out and a common ground for reference.

As long as you have your supply voltage (Within spec) in the V-IN and you hook up the ground, the voltage regulator will output whatever the rated voltage is.

The extra capacitors are known as decoupling capacitors and they're only low pass-filters, essentially, they're recommended but not needed.

The LED is usually hooked up via a 1Kohm resistor. You want to choose a resistor that gives the LED its rated supply current, but more doesn't hurt.

Yori

Well, that's why I asked what resistor and LED you used. Different color LEDs run off different voltages. Well, that usually only goes for the clear ones. Ones with colored lenses usually use the same voltage as white LEDs. The LED's package usually has the voltage it runs off of (Forward Voltage or Voltage Drop)

EDIT: jfkfhhfj beat me, and also noticed something I didn't. Though, I do wonder why you got a rectangular LED.

oh dang

Well i did try it even though the LED didnt light up, and it wasnt supplying power to the board. I forgot to get my volt meter and test it. I went with a spare rectangular LED cause it fit in better also. Its a red LED i dont remember what the resistance is on the resistor was, it was the same one i had used when i built the power supply on the breadboard via the instructions that came in the kit, so i figured it'd work. Ill have to check it out.

edit: if i remember correctly i believe the resistor was brown brown red.

Yori

Brown brown red = 1.1k ohms, or 1100 ohms. I'd say the LED might not be getting enough power. Check that with a volt meter before de-soldering, though! Using the resistance formula, I got 165 ohms for a red LED. Just go with a 220 ohm, or the next highest resistor you have.

jfkfhhfj

I Kohm is fine, for power LEDs you don't want them sucking much power. You just want it as an indicator.