Chapter 1
What is paper circuit?
Paper circuit is the electronics circuit which designed on paper instead of PCB.
Using paper circuit you can make a lot of interactive things like interactive greetings card, small electronics projects, can combine art with electronics by embed LED’s in paintings and drawings and many more.
There is no wires in the paper circuit as you can replace them by a conducting aluminum tape which is shown in img01 below.
The main advantage of paper circuit is you can make a circuit anywhere you wanted to. Like if you wants to make a circuit on your wall the it is not convenient to use PCB on your wall, in this case you just need to paste an aluminum tape at anywhere on your wall and complete the path of the circuit and your circuit is ready even without wires and pcbs.
Components use in paper circuit
- Conductive tapes
- Coin cell battery
- LED’s
- Foam battery holder
Conductive tapes:
There is two type of conductive tape you can use
1)aluminum tape
2)copper tape
Thickness of the thape: what is the thickness of the tape?
different available width:what are the available with?
Coin cell battery:
There are three types of coin cell batteries we can use with the paper circuit.
1)CR2032: The image below shows the CR2032 battery which you can use in paper circuit.
The upper side of the battery is positive terminal and the lower side of the battery is negative terminal you need to connect the led accordingly.
CR2032
Voltage: the voltage of CR2032 is 3V
Capacity:220mah
Current: 0.2 mA
Diameter:20 mm
Thickness:3.2
2)CR2025: CR2025 is as shown in image.positive terminal is upper side and negative terminal will be at lower side.
Voltage: the voltage of CR2032 is 3V
Capacity:163mah
Current: 0.2 mA
Diameter:20 mm
Thickness:2.5
3)CR2016:
Voltage: 3V
Capacity:90mah
Current: 0.2 mA
Diameter:20 mm
Thickness:1.6
LED’s:
we can use all type of LED’s(red,green,blue,RGB).
How to connect a LED?
There is two terminal of the led, one is positive and another one is negative.
We can distinguish between positive and negative terminal depends on the length of the leads of the LED or as shown in image at the right.
Long lead is positive while Short is called negative terminal of the led.
We need to connect the LED accordingly to the coin cell battery to glow LED.
How to connect multiple LED’s:
There is two ways to connect multiple LED’s with single battery
1) Parallel connection: 2)Series connection:
The above image shows the parallel connection of the led. According to this the positive terminal of all the led connected commonly to the positive terminal of the battery.
And the negative terminal of all LED’s will be connected commonly to the negative terminal of the battery.
The series connection of LED will be as shown in the image above.
As the voltage drop will not be same in series connection, we can’t use it for more led’s.
Foam battery Holder:
For paper circuit we can make foam battery holder by cutting the foam according to the shape of the battery.
It is convenient to use foam piece As the foam is flexible. so the flexibility of our circuit can be maintain.
The voltage drop will be same in parallel connection so we can glow more leds with parallel connection.
It is most commonly used method connect multiple LED’s
Other ways to holding batteries:??
By the blinder clip we can also hold the battery.
Chapter2
How to work with Paper circuit
Step1: print the layout of the circuit as shown in image
Step2: Start sticking the tap from center of the placement of battery to the negative end of the led.
Step3: Cut the the tap at the negative end of the LED
Step4: Start sticking the tap from the positive End of the LED to the placement of battery.
Step5: fold the strip of the tap as only upper side of the tap has good conductivity
Step6: place the LED at its place and note the positive and negative terminal of LED
Step7: stick the positive and negative end of the Led to the track of the circuit
Step8: place the battery holder and stick it with insulating tap on the paper but take care of the track, it should not be insulate otherwise circuit won’t be completed
Step7: Place the battery at its place
Step8: fold the another side of the paper
Step9: press at the placement of the battery, it will connect the positive end which is in the air to the positive terminal of the battery.
Here our paper circuit is ready
Tape bending Technique:
Things to take care with paper circuit(FAQ)
(1)I follow the steps and completed the circuit but LED is still not working, why?
- Troubleshoot your circuit by following this steps
Step1: Press the track smoothly where the LED legs are placed might the connections are loose.
Step2:Check the placement of the battery whether it is placed according the positive and negative terminal of the led or not.? If it is not connected accordingly then replace it accordingly. If still not working then take step3.
Step3:If it is connected according to positive and negative terminal of the battery then check the LED if it is working properly or not?
Step4: if the placement of the LED and the battery is correct and your LED is also working then your battery might be discharged. Check your battery voltage by multi meter.
Step5: if you checked all the steps and the circuit is still not working then troubleshoot this problem by checking the continuity of the track by multi-meter.
(2)What is the positive (or negative) lead on an LED? How do you determine the polarity of the LED?
- The longer lead of LED would positive terminal while the shorter lead of led would be negative terminal of the LED.
- If the LED has two leads with leads that are equal in length, you can look at the metal plate inside the LED. The smaller plate indicates the positive (anode) lead; the larger plate belongs to the negative (cathode) lead. Unfortunately, some jumbo LEDS have the plates reversed so this is not a fool-proof method. Better to check with battery once.
(3)What if I placed LED in reverse order ?
- If the LED placed in reverse order it wont glow, in this case either you need to reverse the polarity of battery or the polarity of LED it self.
(4) I connect 4 LED in parallel but only two is glowing ?
- Check the polarity of the LEDs which are not glowing might it is not according to battery and other two LED’s.
(5) The polarity of the LEDs is according to polarity of battery but the it is not working.?
- If it is according to polarity of the battery then check the LEDs with battery separately.
- Or check with other battery might the battery is discharged
(6) What is the positive and negative of the battery?
- The upper side of the battery is positive.
- The lower side of the battery is negative.
(7) How I get to know the battery is charged or discharged?
- You need to check with multimeter by keeping the multimeter adjustment to 20V and put the positive and negative lead of multimeter the battery accordingly.
- If the output of the battery is near to 3V then it is charged.
- If it is too low than 3V so its discharged, you need to change the battery.
(8) Aluminum tape is conductive at both the upper and lower side?
- The tape is conductive at upper side but it is partially conductive from lower side.
- Better to use the upper side for good output.
(9) How get to know that the end to end connection is completed ?
- You can check the end to end connection by checking the continuity by multi-meter.
- For that you need to set the adjustment of multi-meter to continuity and put the two leads of multi-meter to both end.
- If the buzzer sound your connection is proper otherwise it might be disconnected from somewhere.
(10) How to do end to end connections with tape ?
- For end to end connection it is recommend to not cut the tape, instead paste the tape without any cut.
(11) How paste the tape on curved path without cutting the tape ?
- At curved path you need to fold the tape at 45 degree in the opposite direction of the actual path you wanted to.
- It will help you for taking curved path with tape.
Sample Projects:
- Valentine’s day greeting cards
- Light up Eiffel Tower using paper circuit
- File security system using paper circuit
