Transformerless Power Supply Circuit: A Step-by-Step Guide


In today's blog, we embark on a journey to demystify the creation of a universal transformerless power supply circuit that converts 220V AC to DC, a fundamental component for countless electronic projects. Before delving into the intricacies of the circuit, let's emphasize the paramount importance of safety when working with 220V AC. Always prioritize safety measures to avoid potential hazards.

Power Supply Circuit
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Essential Components:

To Embark on this Transformative DIY project, gather the following components:

  • 2.2uF 400V Capacitor
  • 470uF 100V Capacitor
  • 470k 1W Resistor
  • 100R 1W Resistor
  • 220R 1W Resistor
  • 1K Resistor
  • 1N4007 Diode (x4)
  • Zener Diode (voltage depends on your requirements)
These components are readily available at your local market or even within old emergency rechargeable lights or torches.

Building the Circuit:

If you possess the technical know-how, proceed with assembling the circuit. However, if you lack the expertise, I strongly advise against attempting this, as it involves potential electrical hazards.

For those not inclined towards the intricacies of a transformerless circuit, an alternative is a transformer power supply, which is simpler to construct. A video tutorial on YouTube further simplifies the process for the uninitiated.

Schematic Diagram:

The schematic diagram reveals the heart of the circuit. The 2.2uF 400V capacitor is connected in series, accompanied by a parallel connection of a 470k 1W resistor. Pay close attention to the capacitor's polarity during the assembly process. The 470uF 100V electrolytic capacitor requires precise connection according to the schematic diagram.

Transformerless Power Supply Circuit:

Diode Dynamics:

The 1N4007 diodes play a pivotal role in the circuit, forming a bridge rectifier configuration that converts AC to DC. To enhance the DC output, a capacitor is connected to the bridge rectifier. The versatility of the Zener diode becomes apparent here, allowing customization of the output voltage. This adaptability solidifies the circuit's claim as a universal power supply.

Additional Features:

Incorporating an LED as an indicator adds a visual element to the circuit, signaling its operational status. However, exercise caution and refrain from touching the DC output, as safety features are not integrated, and contact may result in a mild electric shock.

PCB Design for Compact Elegance:

For enthusiasts seeking a more compact and visually appealing setup, a customized PCB design is available. The Gerber file can be freely downloaded, and for PCB orders, JLCPCB offers a $30 new user coupon code through our referral link: []. Registering via this link ensures a seamless ordering experience for your custom-made PCB.

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In conclusion, this universal transformerless power supply circuit offers versatility and customization, making it an ideal choice for various applications. However, caution is paramount, especially for those unfamiliar with the technical nuances. Embrace the simplicity of a transformer power supply if uncertainties persist.

Q&A for SEO Domination

Q: How does the universal transformerless power supply circuit differ from traditional transformer power supplies?

A: The universal transformerless circuit provides adaptability in output voltage through the use of a Zener diode, offering versatility for diverse applications. Traditional transformer power supplies may lack this level of customization.

Q: What safety measures should be prioritized when working with the circuit?

A: Safety is paramount when dealing with 220V AC. Always exercise caution, avoid direct contact with the DC output, and consider opting for a transformer power supply if you lack technical expertise.

Q: Why choose JLCPCB for PCB orders?

A: JLCPCB stands out for its user-friendly interface, quality PCB manufacturing, and the exclusive $30 new user coupon code offered through our referral link []

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