A simple battery charger is an important device made to refill energy in rechargeable batteries.
In this article, we will explore a simple DIY battery charger circuit using center tap transformer that works great for charging lead acid batteries.
This setup can charge all kinds of 12V rechargeable batteries, and even the car batteries.
This circuit is not only efficient but also easy to build.
It uses basic parts making it capable of charging batteries that run on either 6V or 12V.
Because of this it is a fantastic choice for hobbyists and fans who want to take on hands on this projects.
Circuit Working:
Parts List:
| Component | Specification | Quantity |
|---|---|---|
| Capacitor | Electrolytic 2200µF 25V | 1 |
| Center Tap Transformer | Steps down the mains voltage 230V AC to 12-0-12V 5A | 1 |
| Diodes | 1N4007 | 2 |
| Ammeter | 0-5A | 1 |
| Rechargeable Battery | battery to charge | 1 |
Check out the circuit diagram above that comes with this explanation to get a better idea of how everything works.
This circuit has some important parts like a center tap transformer, diodes a capacitor and an ammeter and each one is really important for charging.
The transformer changes the high mains voltage down to a safer 12V AC.
Then, two diodes D1 and D2 are used to make a full wave rectifier which changes the AC voltage into a bumpy direct current DC.
To make this output smoother a capacitor C1 is added to reduce the bumps giving us a steadier DC voltage.
This smoother DC voltage is sent to the battery to charge it up.
Plus the ammeter is included in the circuit so you can see how much current is going into the battery letting you keep an eye on the charging process as it happens.
Note: Make sure to connect the charger to the battery the right way, you need to connect positive end of the battery to positive supply and the negative end of battery to negative supply.
Formulas with Calculations:
Formulas with calculations for Simple DIY Battery Charger Circuit using Center Tap Transformer is mentioned below to design your own battery charger circuit at home:
Transformer Rating:
Secondary voltage = 12V RMS.
Peak voltage (√2 × RMS) = 12V × 1.414 = 16.97V
Capacitor Value:
Load current = 5A
Ripple voltage (∆V) = 2V (assumed)
Capacitor value (µF) = (I × t) / ∆V
For a full-wave rectifier:
t = 1/(2 × f) = 1/(2 × 50) = 0.01s (for 50Hz AC)
C = (5 × 0.01) / 2 = 0.025F = 25000µF approx
Using a 2200µF capacitor results in higher ripple but is adequate for this simple circuit.
Diode Ratings:
Peak inverse voltage (PIV) = 2 × Peak voltage = 2 × 16.97V = 33.94V
The 1N4007 diode has a PIV rating of 1000V which is more than sufficient
How to Build:
To build a Simple Battery Charger Circuit using Center Tap Transformer following steps will help for DIY project and connections:
- Gather all the components mentioned in the above circuit diagram.
- Connect the upper outer wire of transformer to anode of diode D1 and cathode of diode D1 positive of capacitor C1.
- Connect the center tap wire of transformer to negative of capacitor C1.
- Connect the positive of capacitor C1 to the common cathodes of both the diodes D1 and D2
- Connect the positive of capacitor C1 to positive of ammeter and negative of ammeter to positive of 12V lead acid battery.
- Connect the negative of capacitor C1 to negative of 12V lead acid battery
Conclusion:
This Simple DIY Battery Charger Circuit using Center Tap Transformer is a great way to charge lead acid batteries.
It is easy to understand, and you can find the parts without any trouble.
Although this circuit works well for simple tasks adding features like voltage control and protection against overcharging can make it even better and safer.