Showing posts with label design. Show all posts
Showing posts with label design. Show all posts
Wednesday, 29 March 2017
Simple LED Driver Design
The Simple LED Driver Design TCA62735AFLG is a charge pump type DC DC Converter specially designed for constant current driving of white LED. IC can outputs LED current 120mA or more to 2.8-4.2V input. IC observes the power-supply voltage and the output voltage, and does an automatic change to the best of step up mode 1, 1.5 or 2 times. It is possible to prolong the battery longevity to its maximum.This IC is especially for driving back light white LEDs in LCD of PDA, Cellular Phone, or Handy Terminal Equipment.
This electronic project t LED driver is very simple and require few external electronic parts. Due of simplicity of this circuit this project not require additional explanations . If you want to change this design , please consult the manufactured datasheet.
Some features of the TCA62735AFLG electronic project are Switching Frequency : 1MHz(Typ.), Output Drive Current Capability : Greater than 120mA , 4 Channels Built in Constant Sink Current Drivers, Sink Current Adjustment by External Resistance, Soft Start Function , Integrated protection circuit TSD (Thermal Shut Down) .
Friday, 10 March 2017
Home theater design may require professional help
Having to be able to bring home entertainment may be a luxury. This is because only very few households can afford home theater system. Of late, only the rich and the famous can afford such luxury. This notion is now a thing of the past. Home theater systems may now be available to greater number of households because of the knowledge of basic home theater design. The basic home theater design may only require three basic components and these three components may already be affordable for the working class.
However, before you may need to think of the basic home theater design for your home theater system, you may need to know the size of the room for the home theater set up. The size of the room to where the home theater will be set up will depend on how basic the home theater design needs to be.Home theater experts recommends that if the room is quite small, all you need for your home theater design is a television set, three speakers and a DVD player. The home theater design may be dependent of the shpre of the room; however, the position of the speakers remains to be the left, the right and the center of the room. Basic home theater design may require a television set bigger than 27 inches. Too small screen for your home theater design may not be sufficient for a movie theater-like experience.
This is because even for the home theater design, you may need to consider the sight and sound of a movie theater. It is the main consideration why people go to a movie theater, the big screen and the surround sound. With respect to the surround sound of a movie theater, the basic three speakers is only applicable for smaller rooms, if the room is bigger, the home theater design needs to be more than three, you may go up to six speakers and a complimenting subwoofer may be necessary for the surround effect. Going back to a small room, if you will only put three speakers, you may want to consider buying a high quality brand speaker; this will give you enough surround sound for a smaller room.
If you have a small budget, ensure that the store where you will buy your speakers will allow you to test the product in your room and if it will not give you a good surround sound, they should allow you to return or replace the unit. This is because some speakers sound good in the store but when you finally set them up in a small room, the effect is not very good. Find a neat deal where they can allow you to return or replace the speakers. However, if your budget is sufficient, you may consider hiring the services of a home theater designer.
Your home theater designer will be able to design the home theater better and with complete accessories. He may require checking the power rating, and the need for amplifiers. He may also recommend using home theater projectors and he may recommend how the speakers need to be. You will get a good home theater design if you will be able to hire home theater designers. The need for home theater seating and television cabinet may also be necessary for the complete package of your home theater.
You may enjoy the entertainment without having to tide traffic jam and enjoy in your own home theater system.
Sunday, 26 February 2017
The Nexus 8 or Nexus Android 9 L and 64 bit processor could have these features and design
With the introduction of Android L, the latest operating system Google Android Lollipop might be called the Nexus 8 or Nexus 9 could have another design that we had seen.
The Nexus Nexus 8 or 9 remains a mystery and although we saw earlier as might be the design of this new tablet, the latest concept shows us the tablet based on Android L and a 64 bits.
This recreation was created by Vishal Bhanushali and has posted up a video to illustrate what could be the new product from Google.
The Nexus 8 which would be manufactured by HTC would have a soft material at the back to allow it to have a good grip, especially that it would be very thin and light. This rear appears very similar to the rear of the Nexus July 2013.
8 The Nexus runs the latest version of Google's mobile operating system Android Android Lollipop L or (if they end up calling the company), which offers the Material Design (Design Material), as support for 64-bit processors could be Intel or Qualcomm.
Being manufactured by HTC, the Nexus 8 would have the two speakers in the front that are named BoomSound.
According to the creator of this concept, the Nexus 8 would result by the minimalist aspect of L and Android Nexus devices, like the good style that HTC has shown in recent years.
Although this is only a concept, it is very possible that Google present Neuxs 6 and 8 together with Android Nexus L (Lollopop) possibly in October this year. Wait for it to arrive this date to find which is what Google actually has prepared for us.
The Nexus Nexus 8 or 9 remains a mystery and although we saw earlier as might be the design of this new tablet, the latest concept shows us the tablet based on Android L and a 64 bits.
This recreation was created by Vishal Bhanushali and has posted up a video to illustrate what could be the new product from Google.
The Nexus 8 which would be manufactured by HTC would have a soft material at the back to allow it to have a good grip, especially that it would be very thin and light. This rear appears very similar to the rear of the Nexus July 2013.
8 The Nexus runs the latest version of Google's mobile operating system Android Android Lollipop L or (if they end up calling the company), which offers the Material Design (Design Material), as support for 64-bit processors could be Intel or Qualcomm.
Being manufactured by HTC, the Nexus 8 would have the two speakers in the front that are named BoomSound.
According to the creator of this concept, the Nexus 8 would result by the minimalist aspect of L and Android Nexus devices, like the good style that HTC has shown in recent years.
Although this is only a concept, it is very possible that Google present Neuxs 6 and 8 together with Android Nexus L (Lollopop) possibly in October this year. Wait for it to arrive this date to find which is what Google actually has prepared for us.
Sunday, 11 December 2016
IC 555 Design Note Circuit Diagram
The popular Timer IC 555 is extensively used in short duration timing applications. IC 555 is a highly stable integrated circuit functioning as an accurate time delay generator and free running multivibrator. But one of the serious problem in 555 timer design is the false triggering of the circuit at power on or when voltage changes. The article describes how IC555 is designed perfectly to avoid false triggering.
555 IC pin functions
Pin1 Ground
Pin2 Trigger
Pin3 Output
Pin 4 Reset
Pin 5 Control voltage
Pin 6 Threshold
Pin 7 Discharge
Pin 8 Vcc
Functional aspects of pins
Trigger Pin 2
Usually pin2 of the IC is held high by a pull up resistor connected to Vcc. When a negative going pulse is applied to pin 2, the potential at pin 2 falls below 1/3 Vcc and the flip-flop switches on. This starts the timing cycle using the resistor and capacitor connected to pins 6 and 7.
Reset pin 4
Reset pin 4 can be controlled to reset the timing cycle. If pin 4 is grounded, IC will not be triggered. When pin4 becomes positive, IC becomes ready to start the timing cycle. Reset voltage is typically 0.7 volts and reset current 0.1 mA. In timer applications, reset pin should be connected to Vcc to get more than 0.7 volts.
Control Voltage pin 5
Pin5 can be used to control the working of IC by providing a DC voltage at pin5. This permits the control of the timing cycle manually or electronically. In monostable operation, the control pin5 is connected to ground through a 0.01 uF capacitor. This prevents the timing interval from being affected by AC or RF interference. In the Astable mode, by applying a variable DC voltage at pin 5 can change the output pulses to FM or PWM.
Threshold pin 6 and Discharge pin 7
These two inputs are used to connect the timing components- Resistor and Capacitor. The threshold comparator inside the IC is referenced at 2/3 Vcc and the trigger comparator is referenced at 1/3 Vcc. These two comparators control the internal Flip-Flop of the circuit to give High or Low output at pin 3.When a negative going pulse is applied to pin 2, the potential at pin2 drops below 1/3 Vcc and the trigger comparator switches on the Flip-Flop. This turns the output high. The timing comparator then charges through the timing resistor and the voltage in the timing capacitor increases to 2/3 Vcc.( The time delay depends on the value of the resistor and capacitor.
That is, higher values, higher time).When the voltage level in the capacitor increases above 2/3 Vcc, the threshold comparator resets the Flip-Flop and the output turns low. Capacitor then discharges through pin 7.Once triggered, the IC will not responds to further triggering until the timing cycle is completed. The time delay period is calculated using the formula T= 1.1 Ct Rt. Where Ct is the value of Capacitor in PF and Rt is the value of Resistor in Ohms. Time is in Seconds.
How to eliminate false triggering?
The circuit diagram shown below is the simple monostable using IC 555. To eliminate the false triggering resistor R1 and Capacitor C1 are connected to the reset pin 4 of the IC. So the reset pin is always high even if the supply voltage changes. Moreover capacitor C3 connected close to the Vcc pin 8 acts as a buffer to maintain stable supply voltage to pin 8. Using this design, it is easy to avoid false triggering to a certain extent.
555 IC pin functions
Pin1 Ground
Pin2 Trigger
Pin3 Output
Pin 4 Reset
Pin 5 Control voltage
Pin 6 Threshold
Pin 7 Discharge
Pin 8 Vcc
Functional aspects of pins
Trigger Pin 2
Usually pin2 of the IC is held high by a pull up resistor connected to Vcc. When a negative going pulse is applied to pin 2, the potential at pin 2 falls below 1/3 Vcc and the flip-flop switches on. This starts the timing cycle using the resistor and capacitor connected to pins 6 and 7.
Reset pin 4
Reset pin 4 can be controlled to reset the timing cycle. If pin 4 is grounded, IC will not be triggered. When pin4 becomes positive, IC becomes ready to start the timing cycle. Reset voltage is typically 0.7 volts and reset current 0.1 mA. In timer applications, reset pin should be connected to Vcc to get more than 0.7 volts.
Control Voltage pin 5
Pin5 can be used to control the working of IC by providing a DC voltage at pin5. This permits the control of the timing cycle manually or electronically. In monostable operation, the control pin5 is connected to ground through a 0.01 uF capacitor. This prevents the timing interval from being affected by AC or RF interference. In the Astable mode, by applying a variable DC voltage at pin 5 can change the output pulses to FM or PWM.
Threshold pin 6 and Discharge pin 7
These two inputs are used to connect the timing components- Resistor and Capacitor. The threshold comparator inside the IC is referenced at 2/3 Vcc and the trigger comparator is referenced at 1/3 Vcc. These two comparators control the internal Flip-Flop of the circuit to give High or Low output at pin 3.When a negative going pulse is applied to pin 2, the potential at pin2 drops below 1/3 Vcc and the trigger comparator switches on the Flip-Flop. This turns the output high. The timing comparator then charges through the timing resistor and the voltage in the timing capacitor increases to 2/3 Vcc.( The time delay depends on the value of the resistor and capacitor.
That is, higher values, higher time).When the voltage level in the capacitor increases above 2/3 Vcc, the threshold comparator resets the Flip-Flop and the output turns low. Capacitor then discharges through pin 7.Once triggered, the IC will not responds to further triggering until the timing cycle is completed. The time delay period is calculated using the formula T= 1.1 Ct Rt. Where Ct is the value of Capacitor in PF and Rt is the value of Resistor in Ohms. Time is in Seconds.
How to eliminate false triggering?
The circuit diagram shown below is the simple monostable using IC 555. To eliminate the false triggering resistor R1 and Capacitor C1 are connected to the reset pin 4 of the IC. So the reset pin is always high even if the supply voltage changes. Moreover capacitor C3 connected close to the Vcc pin 8 acts as a buffer to maintain stable supply voltage to pin 8. Using this design, it is easy to avoid false triggering to a certain extent.
555 Monostable circuit
A ready recknor to select timing resistor and capacitor
Theoretically long interval is possible with IC 555,but in practical conditions, it is difficult to get more than 3 minutes. If low leakage Tantalum capacitor is used, this can be increased to 5 minutes or more. If the value of the timing capacitor is too high above 470 uF, charging time will be prolonged which will upset the timing cycle and the output remains high even after the desired time is over.
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