Showing posts from 2017

how to make an automatic faucet

Now you will not forget to close your faucet or waste water when you pick a soap to wash your hand or face. This project shows you how to make an automatic faucet, you can even use the faucet that water valve damage because of this circuit use solenoid valve to control water.Electronic components you need:
1 Arduino Uno R3
1 TR1 = IRF 540n N channel MOSFET
1 Sensor1 = IR sensor
1 IR1 = IR led
R1 = 10 kilo-ohms
R2 = 100 ohms
R3 = 4.7 kilo-ohms
1 12 volts solenoid valve
12 volts 1 Ampere adapter

The Arduino code is very simple and you don't need to load any special module to make this project works

 created 29 Dec. 2008
 modified 9 Apr 2012
 modified 20 Oct 2017
 by Tom Igoe

 This example code is in the public domain.


// These constants won't change.  They're used to give names
// to the pins used:
const int analogInPin = A0;  // Analog input pin that the ir sensor is attached to
const int analogOutPin = 9; // Analog output pin that the LED is attached to

int senso…

3 ways touch selector switch circuit diagram

Hello, today I'm going to show you how to make a 3 ways touch selector switch. This electronic project makes you switch 3 electronic loads  (light bulb, electric fan) to switch on/off by touch the sensor.
Let's start!!!
Components you need:R1,R2,R3,R4,R5,R6 are 1 kilo-ohms resistor R7 = 10 kilo-ohms IC 1 = CD4017BE Relay 1,2,3 are 5 volts relay  TR1,2,3 are BD139 npn transistors led 1,2,3 = low power led red,green,blue C1 = 2.2 uf T1 = touch sensor

This circuit use 4.5 - 5 volts power supply, so you can use 3 AA battery, USB power, or 4 AA rechargeable battery as you need. Use power supply over 5 volts not make circuit broken but the relay must be changed to 12 volts power supply type and you must use 5 volts regulator for touch sensor module. 

All you need to do next is watching my video below

Combine 3 speakers to one amplifier

I saw a question in my Youtube video about how to combine speakers for one amplifier unit without making any damage to an amplifier. An speaker impedance must be match or higher than an amplifier manufacturer specification, if you use lower speaker impedance than an amplifier specification, your amplifier may end up damaged or make a fire when you play loud music.
A commercial amplifier can handle between 4 - 16 ohms speaker impedance and maybe lower to 2 ohms for car subwoofer amplifier. but in a question, he asked me how to combine 3 speakers @ 6 ohms load to one amplifier.

The simple solution is to make 3 separate amplifiers and share same input, but it makes the circuit more complicated and uses many electronic components. However, if connect all 3 speakers in series, it will make impedance equal to 18 ohms and it makes an amplifier output drop so much.

So, I use 2 speakers connect in parallel and series to other speakers like an image below

SP 1 and SP 2 impedance drop to 3 ohms beca…

5 watts amplifier TDA7056A wiring diagram

TDA 7056 A is an audio power amplifier IC that has 5 watts output power with 8 ohms speaker and 3 watts with 16 ohms speaker.The IC is simple to wiring and needs only 6 external components to make the amplifier working. TDA 7056A working with a power supply between 4.5 - 18 volts so the IC can use a battery as power supply. if you use more than 9 volts, you need to attach small heat sink to the IC.TDA7056A has a built-in DC volume control so you can control the gain of the amplifier by changing voltage value at DC volume control pin by use a potentiometer. DC volume control makes you connect the audio signal directly to the amplifier input so it makes a sound more transparent and cleaner than a normal amplifier. 
The IC has a short circuit protection, over temperature protection, No switch-on/off clicks, ESD protected on all pins, Mute mode (The IC switch mode when DC volume control pin voltage lower than 0.3 volts) 

TDA 7056A has a very wide audio bandwidth 20 Hz to 300 KHz (Hi-fi ampl…

How to remove scratch coating from mobile phone camera

Now a day a mobile phone camera lens cover coating with anti-glare, scratch resistance. However, every coating material can be scratched easily even the smartphone camera coating with scratch resistance material, and it makes the camera quality drop significantly. 
The best way to fix this problem is removing the scratches coating off the camera lens cover, but you need to remove it the right way or you may end up make more scratches to the camera lens cover.
My instruction is easy to do and make a pleasant result. All tool you need is old sim card adapter and car polishing(no rubbing bead type)
You may have a question in your mind that why I use sim card adapter as the rubbing tool. - The simple answer is a sim card adapter made of plastic that softer than commercial cell phone camera lens cover.
Please check the video below for the instruction and before and after comparison.

Awesome ideas with inner tire tube

Hello everyone, today I will show you how to save money with old inner tire tube. Next time when you change a tire tube to a new one, you should not put it in a bin ;) See the video below and see how it works.

security door alarm circuit diagram

Hello, today I will show you how to make a security door alarm, the door alarm is easy to make and give the best result.The door security alarm provides a very long battery life and easy installation, the circuit use only 2.4 volts to operate so you can power the circuit with 2xAA rechargeable battery or even you can use a lithium-ion battery with auto charging circuit as power supply because the circuit can withstand up to 5 volts power supply. 
If you want to change the power supply to 12 volts, you simply need 7805 IC to regulate 12 volts to 5 volts without any problem. You also can use 12 volts Buzzer instead 5 volts Buzzer that I used in the circuit and connect directly to 12 volts power supply (solar charger's output, 12 volts car battery). The SCR (thyristor) in this circuit can withstand current up to 3 A so you can connect 20 Buzzers (estimate 100 milliamp/hour per Buzzer) with one circuit module without making any damage to The SCR. You also can change the SCR model if you…

lm3914 schematic diagram and test

If you want to make a simple VU meter. LM3914 is the best choice for you. It's easy to make VU meter or 10 dot/bar DC level meter with lm3914.  lm 3914 can withstand +-35 volts input without any damage so you can make VU meter even you are new in electronic DIY.
The circuit uses minimal component to make the job done. List of component: R1 = 1 kilo-ohms R2,R3 = 4.7 kilo-ohms R4 = 10 kilo-ohms ic = lm 3914n-1 (lm3914) C1 = 4.7 uf at least to 47 uf (better bass respond) 10 LEDs red,green,yellow,orange or whatever you want 9 - 12 volts DC power supply
LM3914 schematic diagram
   Lm3914 VU meter video, the video show step by step guide and circuit explanation.
Now, I add a sine wave rectifier circuit to lm3914, it makes the dot mode more accuracy.
Real dot mode VU meter schematic diagram

Stereo left right sound test

If you reverse left speaker and right speaker position, you will see picture move right but sound move to left, that seem annoying. Now it's time to correct a mistake!!!

simple bass booster circuit diagram

This bass boost diagram is easy to build and work well, I made it because people asked me the schematic diagram of bass boost diagram on my youtube channel.

The circuit has 9 dB gain@40 Hz that mean you will get good bass performance even you play music to a small speaker. Why this circuit doesn't look like circuits on the internet?
Almost every circuit on the internet uses R/C filter between pre-amp and power amp stage to bypass high frequency to a ground and that seems audio signal being amplified and bypass to ground. I think it wastes pre-amplifier gain, the more gain preamp stage the more distortion to the audio signal, so I use a capacitor to send more negative feedback to pre-amp negative input when the frequency higher than cut-off frequency, capacitor impedance(resistance) higher when frequency lower and that make negative feedback decrease when frequency lower.
An op-amp distortion lowers when negative feedback higher, that mean high-frequency distortion lower when you use …

Infrared proximity sensor circuit diagram

An infrared proximity sensor is a sensor that detects any object when it close to the sensor. The circuit is an important part of an automatic faucet, robot, and touchless switch.
An above image is an infrared proximity sensor circuit diagram. The circuit is simple and easy to make, it has 2 transistors, 4 resistors, an IR LED, an IR phototransistor, and a purple or white or green LED (use as an indicator so you can remove it if you want)
Electronic components list

This circuit's maximum detection range is 10 centimeters, you can decrease the detector range by changing R2 resistor. Use 7805 regulator IC if you want to use the circuit with 12 volts power supply. The infrared proximity sensor consumes around 50 milliamps per hour when standby and consumes around 80 milliamps(add a relay that consumes 30 milliamps) so you need an external power supply because battery life will not last long. The reason that makes this circuit consume much energy because IR LED need at least 50 milliamps …