Make a Very Useful Electronic kit circuit for a lot of DIY projects

 Make a Very Useful Electronic kit circuit for a lot of DIY projects

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 labeled, so you don't really need a step by step guide to assembling the circuits.

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 find and repair a non-functioning circuit.

I can operate a multimeter, using the correct settings and measurement units.

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

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 student case designs in the photos.

A good way to learn to solder is practicing 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.

It is 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 color 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 labeled 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.

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

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 produced.

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

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.

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 labeled. 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

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 doesn'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 an 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 multimeters will not read above 2MΩ, so you will have to read the color codes.

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 labeling 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 socketThe 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

The Wireless FM Microphone kit is not difficult 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.

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 as well or it will look very bad. I recommend you solder one line of LEDs 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 be reprogrammed 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 the next level.

 Make a Very Useful Electronic kit circuit for a lot of DIY projects

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 labeled, so you don't really need a step by step guide to assembling the circuits.

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 find and repair a non-functioning circuit.

I can operate a multimeter, using the correct settings and measurement units.

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

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 student case designs in the photos.

A good way to learn to solder is practicing 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.

It is 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 color 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 labeled 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.

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

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 produced.

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

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.

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 labeled. 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

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 doesn'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 an 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 multimeters will not read above 2MΩ, so you will have to read the color codes.

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 labeling 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 socketThe 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

The Wireless FM Microphone kit is not difficult 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.

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 as well or it will look very bad. I recommend you solder one line of LEDs 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 be reprogrammed 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 the next level.