Group Assignment #4: Electronics Design

This assignment is about documenting what we learned in Electronics Design week that includes working on test equipment in our lab to observe the operation of one of the echo Hello world boards that we designed this week in our Individual assignment. We checked the operating voltage on the board with a multimeter and used an oscilloscope in our lab to check different waveforms the board was generating at different points in the circuit. We also observed the noise in operating voltage and interpret a signal of blinking LED on the board. We used the variable power supplier in the lab to find out how much current the board is consuming and what is the operating voltage for LEDs.

Objectives of the Group Assignment:

- Understand and use the power supply unit for powering the echo Hello World board
- Understand and use Multimeter to test properties of echo Hello World board such as Continuity, Resistance, voltage,current supply, etc.
- Understand and use Digital Storage Oscilloscope (DSO) to observe the waveforms, check noise of operating voltage and interpret a signal of blinking LED.

Equipment need to be Tested:

- Multimeter
- Variable Power Supply
- Digital Storage Oscilloscope


This series instrument is a tiny hand-held 3 1/2 digital multimeter with good stability, reliability, and anti-drop performance. It has a 15 mm high LCD display that allows for easy reading. The circuit design incorporates an LSI double integral A/D converter as its core, which is protected by an overload protection circuit, resulting in a superior and practical instrument. It can be used to test in-circuit continuity and measure DC and AC voltage, DC current, resistance, diodes, transistors, and temperature.

Continuity test at LED on the board

Voltage test: Real time voltage consumption at eco Hello World board

Testing LED current using multimeter

Testing resistor value using multimeter

Digital Signal Oscilloscope

The digital storage oscilloscope is a device that allows you to save a digital waveform or a digital duplicate of one. It allows us to store the signal or waveform in digital format, as well as perform digital signal processing techniques on that signal, in digital memory. The maximum frequency measured on a digital signal oscilloscope is determined by two factors: the scope's sampling rate and the converter's type. DSO's traces are bright, well-defined, and appear in a matter of seconds.

Specifications of our DSO: At Vigyan Ashram Fab lab, we have BMI Surplus Tektronix TDS 2002 2 Channel 60 MHz Digital Storage Oscilloscope. We used it to check the noise of operating voltage and interpret a data signal of blinking led on one of the Hello World Boards. Following are its specifications.

DSO Operation Modes

Roll mode, store mode, and hold or save mode are the three modes of operation for the digital storage oscilloscope.
Roll Mode: On the display panel in roll mode, highly fast fluctuating signals are displayed.
Store Mode: The signals are saved in memory in the store mode.
Hold or Save Mode: In hold or save mode, a portion of the signal is held for a period of time before being recorded in memory.

How to use DSO

Checking AC current Wave form

AC current Wave form output:

Square signal wave form generated after pushing button on Hello world board.

Square signal wave form containing noise

RPS-3005 DC Regulated Power Supply
Click here to download the manual

At Vigyan Ashram Fab lab, we have a DC Regulated Power Supply of Metravi RPS-3005 with Single Output and Backlit LCD Display of variable 0 - 30V / 0 - 5A DC utilising SMT technology. A reliable, heavy-duty DC power supply suitable for lab work, research, R&D, and industrial use. Its linear design makes for quiet, stable operation with virtually no ripple and minimal delay during conversion, transformation, and adjustment. With a maximum output of up to 30 volts and a current capable of 5 amps, the Metravi RPS-3005 has several other beneficial features: two fully operational modes, back-lit LED display with clear resolution, above-average LCD accuracy (+/- 2.%), and programmable voltage and current. Constant voltage mode and constant current mode are the two operational modes, where you can limit your supply up to certain limit to avoid excess flow of power.

A DC power supply is an electrical device that convert the AC current in to DC current Suply using a rectifier circuit.

Specifications of our DC Regulated Power Supply:

Testing RPS-3005 DC Regulated Power Supply

We used it to provide power to one of the echo hello board circuits by providing 5V and 0.20A power supply limit after considering the power consumption of individual component.

The board consumes around 5V and 0.068 A to power up. Therefore, the power consumed by the board with LED on = 5V x 0.068A = 0.34 W. In this way we calculate the power consumption of any circuit or device.