In this article, we discuss about a Simple Power Bank Circuit to Charge Mobile Phone, because this circuit is easy to make at home using few parts.
Also, it is good for emergency when there is no power and it also help to charge phone anytime and anywhere.
Parts Needed for Power Bank Circuit:
- The battery give power to phone charging circuit and when its full charged, it make around 8.2V.
- IC 7805 is popular part for controlling voltage and it is linear voltage regulator its main job is to make battery 8.2V go down to steady 5V for phone charging.
How to Build:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Semiconductors | IC 7805 Voltage Regulator | 1 |
| Power Source Li-ion Battery 7.4V | 1 | |
| Electronics Mobile USB Port for Charging | 1 |
How to Connect Everything:
- First, connect Li-ion battery positive to 7805 input (Vin).
- Next, battery negative connects to ground of circuit.
- Then 7805 gives output steady 5V from output pin (Vout).
- After that, use wire to connect 7805 output to USB port positive pin.
- Next, connect 7805 ground pin to USB port negative pin.
- Also, USB port positive and negative connect to phone charging cable, USB port must give 5V to charge phone properly.
- We can also add protection parts like fuse or over voltage circuit to keep things safe.
- Also can put LED or voltage meter to see battery level or charging status.
- Finally, this whole circuit uses IC 7805 to change battery 8.2V or 8.4V down to stable 5V.
- Then this 5V connects to USB for charging phone or other smart device when outside, as it work with normal phone charging rules.
Parts for Charging Power Bank Battery at Home:
9V AC-DC Adapter:
9V Zener Diode:
- Zener diode controls voltage to TIP35 transistor base and also it gives steady 9V reference, so this circuit uses 9V Zener diode for stable working.
TIP35 Transistor:
- TIP35 work like emitter follower here and emitter gives almost same voltage as base just little less because of diode drop and also it help pass right voltage to battery for charging.
Connection Details:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistor | 100Ω 1W Resistor | 1 |
| Semiconductors | TIP35 Transistor | 1 |
| Zener Diode 9V 1W | 1 | |
| Power Source Li-ion Battery 7.4V | 1 |
- First, connect Zener diode anode to 9V adapter positive.
- Next, Zener diode cathode connects to circuit ground and from Zener cathode wire connects to TIP35 base pin.
- Also, connect TIP35 emitter pin to ground and TIP35 collector pin connect to Li-ion battery positive.
- Battery negative must connect to ground too.
- Further, we can also use resistor or sensor to check charging and control current as needed and this will help charge battery safely and properly.
Formulas and Calculations:
Important things while using Power Bank to Charge Phone and here is easy formula to know charging time:
Charging Time = Battery Capacity / Charging Current
where:
- Charging Time (t) means how long it take to fully charge phone battery.
- Battery Capacity (C) size of phone battery shown in mAh or Ah.
- Charging Current (I) is how much current power bank gives in mA or A.
Example:
Say phone battery is 3000mAh and power bank gives 1000mA current.
Charging Time = 3000mAh / 1000mA = 3 hours
First, to charge phone from 0% to 100%, it take around 3 hours with 1000mA power bank, but however, this is only rough guess, actually, real charging time can change because charging circuit, battery condition and also because of its efficiency.
Circuit Working:
How the charging circuit works is explained below:
Simple Power Bank Circuit to Charge Mobile Phone get steady 9V DC from 9V adapter.
First, Zener diode keep TIP35 base voltage around 8.6V after small drop.
TIP35 works in emitter follower mode, so output at emitter is slightly less, around 8.4V and this 8.4V is good for charging 7.4V Li-ion battery.
Also, TIP35 emitter and battery share same ground and battery positive connects to TIP35 collector.
Further, this simple charger circuit help charge Li-ion battery safely at home using 9V adapter.
Moreover, after battery becomes full, we can use it in power bank to charge phone when there is no power, so it works well for emergency.
Conclusion:
To conclude, this Simple Power Bank Circuit to Charge Mobile Phone is easy to understand with no hard math used so anyone can follow it.
Also, most people just want safe way to charge phone and does not need big calculations so it also show ready-made modules that are easy to use.
Hence, this saves time and there is no headache in building full circuit.
Lastly, short and simple explanation is better to read and remember, and with also make less mistakes so charging stay safe.