How to Convert AC to DC

This article talks about how to convert Alternating Current (AC) to Direct Current (DC). As almost all Electronic devices and circuits use Direct Current (DC) instead of Alternating Current (AC) directly, there is a need for a DC. Though, for a novice it may seem as if is an AC powering Electronic because is plugged on a mains supply from the wall socket or so. But this alternating current in reality is converted into direct current for the consumption of the electronic circuit. This conversion happens by the rectifier circuit section of the electronic device.

Alternating Current (AC) can be converted into Direct Current (DC) by the process – Rectification. Efficiently, a Switch Mode Power Supply (SMPS) gives the best rectification. Alternatively, we will use step down transformer and rectifier diodes for our design as it is cheaper and easier to build. This method is applicable in almost all electronics and circuits. The only problem is that is bulkier when you compare it to the switch mode power supply design.

Using transformer, you will either choose whether a Full Wave or Half Wave rectification is what you will go for. The half wave rectification converts only the half cycle of the AC input into DC. Hence, the DC output is not current sufficient. But however, the full wave rectification converts both the negative and positive cycles of the Alternating Current source into DC. This gives the better result as the output power is more sufficient.

Improving Output

Meanwhile, after rectifying the AC source into DC, there is always too much ripples especially in the half wave rectification. We can always minimize this and have a smooth DC output by connecting a filtering capacitor preferably, an Electrolytic Capacitor (polarized capacitor) in parallel across the output stage.

In this article on how to convert AC to DC, the designs are for

1. Half Wave Rectification using Center Tapped Transformer
2. Full Wave Rectification using Center Tapped Transformer
3. Half Wave Rectification using Non Center Tapped Transformer
4. Full Wave Rectification using Non Center Tapped Transformer

Below are the four (4) designs

In this circuits

• D1-D4 are rectifier diodes
• T is the step down transformer
• F is the fuse
• L stands for “LIVE” while N is the “Neutral” AC source respectively
• C1 to C2 is the filtering capacitor (Polarized Capacitor)