Introduction: Electronic Projects for Beginners

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About: Fixer, Finder, Fabricator. I teach engineering to high school students, at St Marys Secondary College in Nathalia VIC Australia

If your wanting to get into electronics and need a place to start this instructable is for you. There are a number of very cheap kits on eBay and Aliexpress that you can get for 2 or 3 dollars which can give you some experience in component identification, soldering and fault finding. Some of the kits are better than others and they don't come with instructions, but the PCBs are usually well labelled, so you don't really need a step by step guide to assembling the circuits.

If your looking for the Instructable for laser cut cases to fit these kits you can find them here https://www.instructables.com/id/Battery-Cases-for-Electronic-Kits/

Step 1: Learning Intentions and Success Criteria

Learning Intentions

  • To work safely in the workshop.
  • To research electronics and understand basic electronic circuits and components.
  • To operate a multimeter, soldering iron and hand tools.
  • To build and fault find simple electronic kits
  • To be a self-directed learner.

Success Criteria

  • I understand the safety rules and I am working safely in the workshop.
  • I can follow the instructions independently.
  • I can produce a number of kit projects
  • I can safely use a soldering iron to solder PCBs correctly
  • I can fault find and repair a non-functioning circuit.
  • I can operate a multimeter, using the correct settings and measurement units.


Step 2: Where to Get Your Kit?

I got the kits from eBay but other websites like Aliexpress or Banggood also have the same or similar kits.

Flip flop LED flasher $1.25

Sound activated LED Flasher $1.00

DIY Electronic doorbell. $1.82

Electronic LED dice $ 1.69

Lucky rotary LED wheel $1.22

LED chaser $1.24

Wireless FM Microphone $1.55

Electronic LED hourglass . $3.70

Step 3: Before You Start

Before you start it is very important that you be able to identify electronic components and understand if they are polarity sensitive and know how to read component values. You will also have to have good soldering skills, as many of the pins are very close together and poor soldering will ruin your project very quickly.

If you solder a component in the wrong place or around the wrong way your project will likely not work, or your component could be damaged.
Research can easily be done with a google search, here are some names to get you started. Draw up a grid in your folio with a row for each of the following

  • Resistor
  • capacitor
  • Transistor
  • PCB
  • IC . (555) (4017)
  • Microcontroller (1704)
  • IC socket
  • Switch
  • Trimpot
  • LDR
  • Inductor
  • Microphone.
  • Diode
  • Zener diode

In your grid, you need 5 columns for each of the following.

  • Name of component
  • photo
  • symbol
  • A brief description of how to read the components value.
  • Is it polarity sensitive, how can you tell which way around it fits into the PCB

You also need to think about making a case or cover for your project, this can be easily done with a laser cutter or 3D printer and a bit of thought. Check out my other Instructables which will show you how to use the laser cutter and 3d printer, and there are some examples of students case designs in the photos.

https://www.instructables.com/id/Battery-Cases-for-Electronic-Kits/

Step 4: Learning to Solder

A good way to learn to solder is practising on a piece of Vero board and some header pins.

Tips for well-soldered joins are.

  • Make sure the soldering Iron is clean, melt a little solder on the tip and clean off with a wet sponge.
  • Soldering iron need to be up to temperature before you start. Use proper resin core 60/40 electrical solder. (Lead-free solder can be difficult to work with)
  • Heat the pad and the wire with the soldering iron Bring the solder in from the opposite side of the iron Melt the solder onto the pad and wire.
  • Avoid putting the solder directly on the soldering iron when soldering
  • Lots of practice.
  • Cut the excess wire after you have soldered a number of components in.
  • Always use sharp side cutters, and never pull or twist the wire to snap it off, the PCB can be easily damaged.

Step 5: Making a Start.

It usually best to start with the components that will sit low on the PCB first and fit the tallest components last.

Start with the resistors, and either use a resistor colour code chart or multi-meter to check the resistance value before fitting them to the board.

For some reason, many of my students get this wrong and end up with resistors in the wrong location, which can be very difficult to repair.

All the circuit board are very well labelled just keep an eye out for similar looking markings. eg 22K, 22R and 2K2 are NOT the same things. Also, some board are board may use a decimal point eg 2.2K and 2K2 are the same.

The LEDs can also be Labeled in different ways, so make sure you fit them the correct way around. They may have a + or - a diode symbol or a circle with a flat.

Step 6: Flip Flop

A flip-flop circuit is a basis for all sorts of electronic circuits, this one flashes two LEDs alternately. Its the perfect for your first project and can be modified to make the LEDs flash faster or slower. You could use the finished project for a model railway crossing, or tail light for a bicycle.

You will also need a battery and it will work with 3-9 volts

Parts List

  • 2x LEDs
  • 4x Resistors 2x 470R 2x10K
  • 2x Capacitors 47uf
  • 2x Transistors 9014
  • PCB

It also comes with a circuit diagram, but it's in Chinese and hard to read.

Photos show a simple laser-cut case, and a button cell and laser-cut switch were used to keep the size small. The laser-cut cases will be the subject for my next instructable

Step 7: Flip Flop Number 2

Unfortunately, the flip flop shown in the previous step has disappeared off the face of the earth, I can only assume that they are no longer been produced.

This kit is not quite as nice and a little larger has 2 fewer resistors but is pretty much the same.

Parts list

  • 2x LEDs
  • 2x Resistors 2x 68k
  • 2x Capacitors 100uf
  • 2x Transistors 9014
  • PCB

Step 8: Sound Activated LED Flasher

The Sound activated LED Flasher, Is a great beginner project, it has a microphone, and when there is a sound it flashes 5 super bright LED.

It only has a few components and is very easy to build and get working. You will also need a battery and it will work with 3-6 volts

Parts list

  • 5x LEDs
  • 3x Resistors 1M, 10K, 4.7K
  • 2x 9014 transistors
  • 2x capacitors 47uf, 1uf
  • 1x Microphone
  • PCB
  • plug and wiring

It also comes with a circuit diagram.

Unfortunately, there seem to be two versions of this project they sell on ebay, which can lead to some confusion also the PCB is a different size so won't fit the case.

Step 9: DIY Electronic Doorbell.

The DIY Electronic doorbell is also another great little kit, although it doesn't really sound like a doorbell more like a dying frog in an electric fence. There is an error on the circuit board as the 100uf (C5) is not labelled. Of course, you could use this for a doorbell or prank your friends by wiring it to a toilet seat, or locker door. It is an easy kit to assemble and you will also need a battery and it will work with 6-9 volts

Parts List

  • 1xSwitch
  • 1x Speaker
  • 4x Resistors 47K
  • 2x Zener diodes
  • 1x IC 555 timer
  • 5x Capacitors 1x 10uf 1x 100uf 3x10nf (code 103)
  • 1x PCB

There was no circuit diagram with this kit

Step 10: Electronic LED Dice

The Electronic LED dice is a little more difficult it has quite a few more components and doesn't come with an IC socket so you need to make sure you place them correctly in the PCB the first time. Although the kit is well made and it looks nice the dice don't really function properly as you can get some weird LED combinations and its possible to roll a zero. Well, you get what you pay for it was only a $1.69 but a little disappointing.

Thanks to instructable user jimdkc for pointing out the error that makes the dice malfunction. There are 2 errors you need to look out for, first the transistor Q3 on the PCB is mislabeled and should be a 8550. Next some kits only come with one 8550 transistors and there should be two.

The dice works perfectly if the correct (8550) transistor is fitted to Q3

It also has some very high-value resistors, and most cheap multi-meters will not read above 2MΩ, so you will have to read the colour codes.

Parts list

  • 7x LEDs
  • 9x 10K
  • 3x 470R
  • 1x 1K
  • 1x 4.7M
  • 1x 3.3M
  • 1x 10M
  • 3x transistors 8050 and 2x 8550
  • 1 push button switch
  • 2x ICs . 555 and 4017
  • 2x capacitor 1uf and 100pf (code 104)
  • plug and wiring.
  • you will also need a battery and it will work with 3-6 volts

It also comes with a circuit diagram.

Step 11: Lucky Rotary LED Wheel

The Lucky rotary LED wheel Works much better than the dice, you push the button and the LEDs chase around a circle and stop at a random point. You could come up with all sorts of games with it. I had someone suggest a cricket or baseball game by labelling the LEDs 1 run, Home run, foul, ball, strikeout etc.

ICs can be difficult to fit so make sure the pins are straight before you try to plug them into the socket

Parts List

  • 10 LEDs
  • 2x resistors 470K
  • 2x resistors 1.2K
  • 3x capacitors 47uf. 100uf. 100pf ( which has a code of 104 )
  • 2x ICs a 555 (timer) and 4017 (decade counter)
  • 1x push button
  • 1x 9014 transistor

  • you will also need a battery and it will work with 3-6 volts

It also comes with a circuit diagram.

Step 12: LED Chaser

The LED chaser is a great kit and is similar to the Lucky Rotary LED Wheel, but is a little more challenging as it is on a smaller PCB. It also has a trim pot which allows you to adjust the speed. You could use it as a display, or maybe tie it to a bike wheel to make a cool looking POV light. Some of the PCBs have a minor error as the resistors are miss numbered there is no R4

Parts list

  • 12x Resistors 10x 1K, 1x 10K, 1x 2k2
  • 10x LEDs
  • 2x IC 555 and 4017
  • 2x capacitors 1uf
  • 1x trim pot 50K
  • 1x plug and wiring
  • you will also need a battery and it will work with 3-6 volts.

There was no circuit diagram with this kit

Step 13: Wireless FM Microphone

The Wireless FM Microphone kit is not hard to assemble but is very difficult to fault find and get working. It looks like a great kit but it hasn't really got any way of adjusting the transmitter frequency so you may end up with it on the same frequency as a radio station. You can the frequency a little by stretching the inductor coil but this is not ideal. $1.55 disappointment.

Parts list

  • 3x resistors 220R, 22k, 2K2 (they are all different)
  • 7xCapacitors are all the little ceramic type with codes, 103,104, and 10p, 30p
  • 1x Battery Snap
  • 1x switch
  • 1x microphone
  • 1x transistor 9018
  • 1x inductor
  • you will need a 3-volt button cell

There was no circuit diagram with this kit

Step 14: Electronic LED Hourglass

The Electronic LED hourglass is the most difficult kit to assemble as it has the most number of parts and getting the LEDs in the correct orientation it can be confusing. the LEDs all need to be the same height also or it will look very bad. I recommend you solder one line of LEDs in at a time and cut the leads before attempting the next row.

The Hourglass has a microcontroller and a TXD and RXD pins so it should be able to reprogramed to do other things with the LEDs

The Kit comes with a few spare LEDs also, this is because you're likely to find a dud, mine had 2. A great kit and will take your soldering skills to next level.

Parts List

  • 57x super bright LEDs
  • 1x 1704 microcontroller (it not labelled correctly on the PCB)
  • 1x Pushbutton
  • 1x Switch
  • 1x Power socket
  • 1x IC socket
  • 4x header pins
  • you will also need a battery and it will work with 3-6 volts

There was no circuit diagram with this kit

Step 15: Learning More

If you would like to learn more about electronics, download the document and it will help you understand the finer points of how each component works

Attachments

Epilog Challenge 9

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Epilog Challenge 9

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