5v Power Supply Circuit Without Transformer

If a circuit requires very low current of a few milliamperes transformerless power supply is an ideal solution.

5v power supply circuit without transformer.

You get the main supply. Here is the circuit diagram of a 5v transformer less power supply using minimum components. Even if you try to build a traditional dc power supply with transformer the input is still high voltage ac 110. The zener diode regulates the rectifier output to obtain a steady 5v dc and capacitor c2 acts as a filter.

Output currents up to 1a can be drawn from the ic provided that there is a proper heat sink. A 9v transformer steps down the main voltage 1a bridge rectifies it and capacitor c1 filters it and 7805 regulates it to produce a steady 5volt dc. We can convert the high voltage ac into low voltage such as 5v 6v 9v 12v dc without using the transformer which is called transformerless power supply. The purpose of the post is to provide four transformerless power supply circuits and start the discussion.

Instead of discussing how and why the circuits work some readers focus on the dangerous side of the circuits that involve ac. Resistive type power supply on the other hand dissipates more heat so the power loss is quite high. To protect the circuit transformer rectifier capacitor filter an led indicator and the regulator ic. The basic working principle of the transformerless power supply is a voltage divider circuit that converts single phase ac high voltage to a desired low dc voltage without any use of transformer and inductor.

The working of this circuit is quite simple. Circuit diagram of 5v dc power supply. Resistor r1 does the job of current limiting and bridge d1 rectifies the mains voltage. Circuit diagram with parts list.

The basic circuit of the transformerless power supply. It works by using a high voltage capacitor to drop the mains ac current to the required lower level which may be suitable for the connected electronic circuit or load. The whole concept of this power supply involves rectification voltage division regulation and inrush limiting. Electronics projects 230v 5v 1a regulator lm2595t 5 0 without transformer dc dc converter circuit power electronic projects date 2020 02 06 even though regulated circuits over transformerless direct mains voltage are not recommended they are used in many circuits products especially in the lighting industry.

Before designing a transformerless power supply some facts about ac dropping through a capacitor or resistor are to be considered. Voltage and frequency can depend on your country fuse. Below is the circuit diagram for the said project.