Summary of DIY Variable DC Power Supply with Display and PC interface
The article describes an economical, portable bench power supply offering one variable channel (1.2–25 V up to 5 A) plus two fixed channels (5 V/1 A and 12 V/1 A). It includes onboard LCD readout of voltage, current, and instantaneous power, and a serial PC interface for graphical monitoring. The design uses easily available components and is split into a main power module (rectification, filtering, linear regulators) and a microcontroller module for sensing and display; the display module is optional.
Parts used in the DIY Variable DC Power Supply with Display and PC interface:
- Transformer's secondary (suitable for required voltages/current)
- Bridge rectifier (diode pack)
- Filter capacitors
- Linear voltage regulators (adjustable regulator for 1.2–25 V channel; fixed 5 V and 12 V regulators)
- Pass transistors or current-boosting transistors (for 5 A capability)
- Current sensing resistor or shunt
- Voltage divider components (for sensing)
- Microcontroller (for sensing, display, and serial communication)
- LCD display (onboard for voltage, current, power)
- Serial interface circuitry (RS232 level shifter or TTL-to-RS232 adaptor)
- Output terminals and connectors
- Heatsinks for regulators/transistors
- PCB or perfboard and interconnect wiring
- Enclosure and front panel controls (adjustment knob/potentiometer for variable voltage)
Power supply is an utmost essential tool for an electronic lab. It comes in handy for powering up various applications and circuits.
However a fixed voltage, fixed current power supply is sufficient for basic needs but a variable one is good to have because different circuits and components operate at different voltages and consumes different current. When it comes to an electronic hobbyist’s lab, a good power supply is must to have. Also if the power supply boosts additional features like on board voltage and current display, it comes in handy as one can know the exact voltage at the output terminals and also the current drawn by the load. But in the electronic market, those power supplies are not economic are meant for industrial purpose . Here in this article I present an economical and cost effective yet efficient variable bench power supply that is capable of providing 1.2 to 25 Volt variable supply up to 5 Ampere through one channel while 5 Volt, 1 Ampere and 12 Volt, 1 Ampere supply through other two channels thus having one variable and two fixed supply channels. It also displays the voltage on the output terminals and also the current and instantaneous power drawn by the load on an on board LCD display. Not only this one can connect this power supply to his personal computer via the serial port and can see the voltage, current and power drawn by the load graphically. The project is portable and simple to build that even a newcomer can build this power supply with ease and add into his lab. The project uses component that are easily and cheaply available. The project is composed of two modules, one is main power module that consists of linear voltage regulators with rectification and filtering circuitry for supply generation and regulation while the other is composed of a micro controller which is used to sense and display the current and voltage across the variable supply channel. The second section only provides an additional functionality of displaying current and voltage, however one can build the power supply even skipping the second section leaving it functional but without the display feature.(Actually this version 2,I have already build one which was later modified with new features).
For more detail: DIY Variable DC Power Supply with Display and PC interface
- What voltage range does the variable channel provide?
The variable channel provides 1.2 to 25 Volt output according to the article. - What is the maximum current available on the variable channel?
The variable channel can supply up to 5 Ampere as stated in the article. - What fixed output channels are included?
Two fixed channels are included: 5 Volt at 1 Ampere and 12 Volt at 1 Ampere. - Does the power supply display voltage and current?
Yes, it displays voltage, current, and instantaneous power on an onboard LCD display. - Can this power supply connect to a PC?
Yes, it can be connected to a personal computer via the serial port to view voltage, current, and power graphically. - Is the display module mandatory to build the power supply?
No, the microcontroller/display section is optional; the power supply will function without it but without display features. - What are the main modules of the project?
The project is composed of a main power module (rectification, filtering, linear regulators) and a microcontroller module for sensing and display. - Are the components difficult to source?
No, the article states the project uses components that are easily and cheaply available. - Is this project suitable for beginners?
Yes, the article says the project is simple to build and even a newcomer can build it with ease.
