Showing posts with label Power Bank EP. Show all posts
Showing posts with label Power Bank EP. Show all posts

Friday, February 19, 2016

Circuit Schematic Power Bank using 3.7V Li-ion Cells based on 555 IC and Transistors

Eltronicschool. - There are many circuit schematic designed for power bank design and application and give the best result. One application of Power Bank circuit schematic is like look in Figure 1 below. This circuit schematic is Power Bank using 3.7V Li-ion Cells based on 555 IC and Transistors that has been publishing by Homemade Circuit Projects site on January 11th, 2016. You also can read: Circuit Schematic 12V LDO Solar Charge Controller using MOSFET)

In here we will give you review again with this circuit with give you again the circuit schematic Figure, component part, and description about this Power Bank using 3.7V Li-ion Cells based on 555 IC and Transistors. And the last we will give you link to you to read more this circuit and description from original source.

Circuit schematic

Component Parts
  1. 555 IC
  2. Transistors
  3. Resistors
  4. Capacitors
  5. Rectifier Diodes
  6. Zener Diode
  7. Variable Resistors
Description

Circuit schematic like in figure 1 above is Circuit Schematic Power Bank using 3.7V Li-ion Cells based on 555 IC and Transistors. According Homemade Circuit Projects site describe that in order to correct the above situation and make sure that the 3.7V power bank is able to provide the required 4.2V at a consistent rate until the cellphone is completely charged at this level, a step up circuit becomes imperative.

Form circuit schematic above that the inductor L is made by using 5 turns of 22SWG super enameled copper wire over any suitable toroidal ferrite core. Two variable resistors (presets) included in the design, these are required to be optimally set for acquiring the most effective and efficient performance outcome from the boost charger circuit.

The voltage across "C" in this circuit is the output which is used for charging the external device, and in our case the voltage here must be fixed at around 5V. This circuit also includes a built-in 3.7V Li-ion charger circuit made up of a TIP122 emitter follower stage, a 5V zener diode and a small 6V/100mA incandescent bulb.

As long as the 3.7v cell charges through the transistor emitter lead, the series bulb remains illuminated and as the cell nears the full charge level, the illumination on the bulb becomes dimmer until finally it shuts off indicating a full charged 3.7V cell.

The 5V zener diode ensures that the emitter voltage of the TIP122 never exceeds the 5V range, which is further pulled down to around 4.3V by the associated series 1N4007 diode.

Another 1N4007 diodes can be seen connected with the base of the BC557 transistor, this configuration makes sure that the BC557 remains shut off disabling the 555 IC stage and boost converter stage during the charging phase of the cell.

The charging input is preferably obtained from any standard SMPS cell phone charger unit. So the above takes care of a power bank using a 3.7V cell, the AH level depends on the load specs, or the cellphone required to be charged, for smart phones the AH level should be preferably  above 5000mAH.

And for more your information about Circuit Schematic Power Bank using 3.7V Li-ion Cells based on 555 IC and Transistors you can read it fully from original source using link here.

Wednesday, August 5, 2015

Circuit Schematic Power Bank Charger using LM317 IC

Eltronicschool. - Here is circuit schematic for power bank charger based on LM317 IC like in figure 1 below. LM317 IC is popular linear voltage regulator that was invented by Robert C. Dobkin and Robert J. Widlar in 1970 from National Semiconductor. 

Circuit Schematic

Figure 1. Circuit Schematic Power Bank Charger using LM317 IC
(Source: Kit FM Tasikmalaya)

Component Part
  1. LM317 IC
  2. LED
  3. Capacitors
  4. Resistors

Description

Circuit schematic like in figure 1 above is Circuit Schematic Power Bank Charger using LM317 IC. Base in this circuit is LM317 IC as positive voltage regulator with 1.5 A adjustable output. 

And here are some information about LM317 IC like the specification, operation, voltage and current regulator.

Specification


Operation

As linear regulators, the LM317 and LM337 are used in DC to DC converter applications. Linear regulators inherently draw as much current as they supply. When this current is multiplied by the voltage difference between input and output, a significant amount of heat results. Therefore the use of an LM317 commonly also requires a heat sink. For large voltage differences, the energy lost as heat can ultimately be greater than that provided by the circuit. This is the trade-off for using linear regulators which are a simple way to provide a stable voltage with few additional components. The alternative is to use a switching voltage regulator which is usually more efficient but has a larger footprint and requires a larger number of associated components.

In packages with a heat-dissipating mounting tab, such as TO-220, the tab is connected internally to the output pin which may make it necessary to electrically isolate the tab or the heat sink from other parts of the application circuit. Failure to do this may cause the circuit to short.

Voltage Regulator

The LM317 has three pins: INput, OUTput, and ADJustment. The device is conceptually an op amp with a relatively high output current capacity. The inverting input of the amp is the adjustment pin, while the non-inverting input is set by an internal bandgap voltage reference which produces a stable reference voltage of 1.25 V.

A resistive voltage divider between the output and ground configures the op amp as a non-inverting amplifier so that the voltage of the output pin is continuously adjusted to be a fixed amount, the reference voltage, above that of the adjustment pin. Ideally, this makes the output voltage:

Vout = Vref (1 + RL/RH)

Because some quiescent current flows from the adjustment pin of the device, an error term is added:

Vout = Vref (1 + RL/RH) + IQRL

To make the output more stable, the device is designed to keep the quiescent current at or below 100µA, making it possible to ignore the error term in nearly all practical cases.

Current Regulator

The device can be configured to regulate the current to a load, rather than the voltage, by replacing the low-side resistor of the divider with the load itself. The output current is that resulting from dropping the reference voltage across the resistor. Ideally, this is:

Iout = Vref/RH

Accounting for quiescent current, this becomes:

Iout = (Vref/RH) + IQ

LM317 can also be used to design various other circuits like 0 V to 30 V regulator circuit, adjustable regulator circuit with improved ripple rejection, precision current limiter circuit, tracking pre-regulator circuit, 1.25 V to 20 V regulator circuit with minimum program current, adjustable multiple on-card regulators with single control, battery charger circuit, 50 mA constant current battery charger circuit, slow turn-on 15 V regulator circuit, ac voltage regulator circuit, current-limited 6 V charger circuit, adjustable 4 V regulator circuit, high-current adjustable regulator circuit and many more.

Wednesday, November 5, 2014

How to Make Our Self Power Bank from Car HP Charging DC to DC Converter - Electronic Project

Eltronicschool. - Let we continue to make electronic project now. In this time we will show you electronic project on How to Make Our Self Power Bank from Car HP Charging DC to DC Converter. And output of this project we hope you will make your self power bank without must buy power bank from the electronic shop or gadget shop to charge your gadget or HP in everywhere and whenever.

Materials and Tools

Figure 1. Materials and Tools
  1. Cutting pliers, 
  2. Cable cutters pliers, 
  3. Screwdrivers plus and minus, 
  4. Desoldering Ion, 
  5. Tin, 
  6. Battery (rechargeable cultivated), 
  7. Box or casing where the contents 4 batteries , 
  8. ON / OFF switch, 
  9. Terminal cable , 
  10. and the last is a tool that is used to make the process charging in the car.

Step-By -Step to Make it

And now please follow the step by step on how to Make Our Self Power Bank from Car HP Charging DC to DC Converter as follow:
  1. Prepare tools and materials required for the manufacture of power bank as like in figure 1 above.
  2. Once all the equipment is ready, the next step we are ready to make the power of banks, take part which is used for charging the phone in the car, and then unloading and grab the PCB circuit therein, as like the figure 2 below.
    Figure 2. Car HP Charging DC to DC Converter 
  3. Then take the PCB contained therein, the PCB is the one that will be used to lower the voltage or DC to DC Converter term, then we are in the setting PCB Casing that we prepared, we can use a glue gun or glue to attach the PCB into the firing casing.
  4. The next step then we are ready to do the wiring circuit using additional cables, we connect the blue cable is a cable (+) cable to the red and yellow wires are the cable (-) to the black wire, cable, or the positive red color we associate with the switch ON / OFF, and then we connect the cable to the terminal cable as like the figure 3 below.

    Figure 3. Installation of the Material
  5. After the wiring is completed the next step is to conduct a series of testing, how testing can be done by connecting the circuit with a 10V DC power supply and connect with our Hp each. And please you can try to charge your handphone now as like in figure 4 below. and Congratulation.
    Figure 4. Power Bank ready used 
Source: https://utakatikmikro.wordpress.com/2014/01/07/membuat-power-bank-sendiri-untuk-mengisi-battery-hp/