Wednesday, March 4, 2015

Lenovo Pocket Projector Pair to Phones

Robometricschool. - Here is the new product from Lenovo. Lenovo has been launching their new product in MWC 2015. This product is  mini projector that called with Lenovo Pocket Projector. This product named with Pocket Projector to give function as a mini projector that pairs with your phone to shine photos, videos and presentations onto the wall up to 110 inches from corner-to-corner.

Figure 1. Lenovo Pocket Projector

Using the Lenovo Pocket Projector allow you to see the video with 4:3 and 16:10 aspect ratios. It is also allow you to rotate the lens up to 90 degrees to achieve the desirable viewing angles. Beside that this device also complete with two built-in 0.5W speakers, one on each side.

The Lenovo Pocket projector also can accommodate microUSB port supporting multiple mobile platforms. The Pocket Projector sports a microSD card slot that can take up to 32GB of cards and dimension wise it scales at 104x25mm and it is definitely light at just 170gms.

And don’t worry with the battery of Lenovo Pocket Projector, it is because the projector comes with a battery backup of 2.5 hours, which will ensure that you can get through home movies of your holiday without needing to charge the projector.

Read more about from the original article : "How to Pair the Lenovo Pocket Projector to Phones"

Saturday, February 28, 2015

Project Make Your Own USB Mp3 Player at Home

Robometricschool. - Do you want to Make Your Own USB Mp3 Player at Home now? Please follow this article about Project Make Your Own USB Mp3 Player at Home. It is good idea to design your own Mp3 player at home at minimum cost. you can save lots of money if you do it yourself using my Mp3 player circuit and connection diagram. To play Mp3 songs you can use your own computer speaker and amplifier and save the cost of an audio device too.


Components and parts to create a USB Mp3 Player at home:

  1. USB Mp3 Module with Remote (See screenshot)
  2. IR Sensor with Metal case (You can buy it from any TV spare parts shop)
  3. 0-9 AC to Dc (1 Amp.) Transformer (You can buy it from any TV spare parts shop)
  4. Audio Board 6 Volt to 9 Volt (You can buy it from any TV spare parts shop)
  5. IC 7805 with 1000MFD 16 to 25 Volt Capacitor (You can buy it from any TV spare parts shop)*
  6. IN 4007 Diodes(4)  for filter 0-9 power supply.
  7. One blank project matrix PCB Board for mount IC 7805 Power Supply and other components on it.
  8. One USB socket for connecting Pen Drive (USB) to module.
  9. One Audio Jack with pin for connecting speaker to your audio board.
  10. One Volume control (10 K) for control audio output.
Please read more about this project from the original article "Make Your Own USB Mp3 Player at Home"

Wednesday, February 25, 2015

Circuit Schematic PCB Drilling Speed Control using LM555 IC

Robometricschool. - Here is Circuit Schematic PCB Drilling Speed Control using LM555 IC like in figure 1 below. This is a simple, inexpensive and useful circuit for electronics hobbyists. The circuit is nothing but a PCB drill speed controller, which can be used to control the speed of any 12VDC small pcb drilling units. Such portable units are now widely available, and even a hobbyist can make it without too much difficulty.

Circuit Schematic
Figure 1. Schematic PCB Drilling Speed Control

Component List

  1. IC LM555
  2. Diodes
  3. Resistors
  5. IC 7805
  6. Capacitors
  7. LED


Circuit schematic like in figure 1 above is Circuit Schematic PCB Drilling Speed Control using LM555 IC . In this circuit, the renowned timer chip LM555 (IC1) is used as a PWM circuit. The whole circuit can be powered from a standard 12VDC supply, capable of sourcing ample current to the PCB drill motor. As you may noted, power supply for the PWM circuit is down-converted and regulated with the help of a 3-pin fixed regulator chip LM7805 (IC2). This will improve the circuit stability. Precision 50K trimpot P1 is the variable drill speed controller. Finally, a logic-level power Mosfet IRL 530N (T1) is used as the output drive element. This IRL530N mosfet (available in TO-220 package) can handle current upto 27A! Fast switching and Low on-resistance – RDS (on) – are other attracting features. IRL 530N is universally preferred for all commercial-industrial applications at power dissipation levels to approximately 50 watts.

Saturday, February 21, 2015

Circuit Schematic PIC Programmer

Robometricschool. - Do you looking for PIC programmer circuit now? Figure 1 show you Circuit Schematic PIC Programmer. PIC programmer  circuit is a circuit which suitable to do simple pic16f84, pic16f84A, 16c84, 16f628 group programmer.

Circuit Schematic
Figure 1. PIC Programmer Circuit

Component List

  • R1 10KΩ
  • R2 3.3KΩ
  • R3 15KΩ
  • C1 100µF 16V
  • D1 LED
  • Z1 5.1V Zener
  • Q1 BC547
  • PIC PIC16F84,PIC16F84A, 16C84, 16F628
  • Rs232 RS232 Femail Connector
  • IC Base 18 pin ic base fo


Circuit schematic like in figure above is Circuit Schematic PIC Programmer. This circuit schematic using IC base for PIC. Connect the PIC programmer to 1st or 2nd COM PORT of computer by using RS232 wire.

The original article : "PIC Programmer"

Wednesday, February 18, 2015

Circuit Schematic TDA2004 Car Stereo Amplifier

Robometricschool. - Here is good circuit for car audio amplifier. This is Circuit Schematic TDA2004 Car Stereo Amplifier like in figure 1 below. The TDA2004A is a class B dual audio power amplifier in MULTIWATT package specifically designed for car radio applications.

Circuit Schematic
Figure 1. Circuit Schematic TDA2004 Car Stereo Amplifier

Component List
  • R1
  • R2
  • R3 1.2kΩ
  • R4 1.2kΩ
  • R5 3.3Ω
  • R6 3.3Ω
  • R7 120kΩ
  • C1 2200µF 16V
  • C2 2200µF 16V
  • C3 100µF 16V
  • C4 100µF 16V
  • C5 100nF (104)
  • C6 100nF (104)
  • C7 220µF 16V
  • C8 220µF 16V
  • C9 2.2µF 16V
  • C10 2.2µF 16V
  • C11 100nF (104)
  • C12 470µF 25V
  • C13 10µF 16V
  • LS1, LS2 4Ω 10W speaker
  • IC1 TDA2004

Circuit schematic like in figure 1 above is Circuit Schematic TDA2004 Car Stereo Amplifier. With the component values shown and with a supply voltage of 14.4V (a fully charged car battery), the stereo amplifier is capable of delivering a power output of at least 6W, typically 6.5W with a load impedance of 4Ω. It can also handle a load impedance of 2Ω, in which case the output power is a minimum of 9W, but typically 10W. Power outputs of this order are subject to about 10% distortion, however, if lower power outputs are acceptable, 4W with a load impedance 4Ω or 6W with a load impedance of 2Ω, distortion is only in the order of 0.3%.

The voltage gain of the left-hand channel is determined by the ratio of R3 to R5, and that of the right-hand channel by the ratio of R4 to R6. With the values given, this will be 50dB. Therefore, a signal of 50mV is required at the input to give the maximum output. If this input sensitivity is too great, a 50kΩ stereo potentiometer can be included at the input. The impedance of non-inverting amplifier input is minimally 100kΩ.

The original article : "TDA2004 Car Stereo Amplifier"

Sunday, February 15, 2015

Circuit 3A Switching Regulator using LM317

Robometricschool. - Circuit 3A Switching Regulator using LM317 like in figure 1 below is  a simple and low cost switching regulator using the IC LM317 that can deliver up to 3A of current. The input voltage range of this circuit is between 8 to 35V DC and the output voltage can be adjusted between 1.8 to 32V DC. The output voltage can be adjusted by using the POT R4.
Figure 1. Circuit 3A Switching Regulator using LM317


When compared to linear voltage regulators the switching voltage regulators are much power efficient. In the case of linear voltage regulators the difference between the input and output voltage is just wasted and for switching regulators there is almost no such wastage and that’s why the switching regulators have great power efficiency ranging up to 85% . In simple words, the switching regulator operates by taking small bits of energy from the input voltage source and then transferring it to the output with the help of a solid state switch and a control circuitry.

Friday, February 13, 2015

Oxford Dictionary of English 4.0 for Windows - Free Download

Robometricschool. - Here is Oxford Dictionary of English 4.0 for Windows to you. Oxford Dictionary of English is the desktop version of this popular English language dictionary. Oxford Dictionary of English incorporates the newest words.

Please follow this link below to download and more information about  Oxford Dictionary of English 4.0 for Windows.

Thursday, February 12, 2015

Circuit LM723 Positive Floating Regulator

Robometricschool. - Do you want to build your own regulator now? Please use Circuit LM723 Positive Floating Regulator like in figure 1 below.
Figure 1. Circuit LM723 Positive Floating Regulator


Circuit like in figure 1 above is Circuit LM723 Positive Floating Regulator. Floating regulator is a type of voltage regulator that works without a real ground connection. This is a trick used for regulating voltages higher than the rated value. For example the typical output voltage range of LM723 voltage regulator IC is 2 to 37V DC. The upper limit can be pushed beyond 37V DC by using the floating technique.

In floating configuration, the ground pin of the regulator will not be at the same voltage of the return path of the load current. This can be achieved by putting a Zener diode in series to the circuit ground. This makes the circuit tricked into working above the real ground to a voltage equal to the breakdown voltage of the Zener diode. The rated safe difference between the unregulated input voltage and regulated output voltage is easily maintained. In simple words, when the regulator is operating in the floating mode, it sees only the difference between the input and output voltages and voltages much higher than the rated value of the regulator can be regulated.

LM723 floating regulator.

LM 723 is an integrated series regulator from National Semiconductors. Maximum input voltage is 40V and the output voltage range is from 2V to 37VDC. Maximum output current is 150 mA and this can be extended by using external pass transistors. The IC can be configured in linear or switching configuration. The circuit given below  is of a positive floating regulator with external pass transistor. Resistor R1 and R2 sets the output voltage. 36V Zener diode D1 is used to trick the circuits ground to operated 36V (break down voltage of D1) above real ground. R5 is the current sensing resistor which is associated with the internal current limiting circuit. Q1 is the series pass transistor. Capacitor C1 is meant for frequency compensation. Output voltage of the circuit is according to the equation: Vout = (Vref/2) x {(R2-R1) /R1}.