MINI PROJECT GROUP ASSIGNMENT PRESENTATION

TOPIC-STRESS METER

PRESENTERS:- TAMCHI WADIE

SUMAN DEV

DIGVIJAY BHATTACHARJEE

STRESS

Stress is a physiological condition in which the body becomes excited to face an emergency situation.

Increase in heart rate, breathing rate etc occurs during a high stress state.

A permanent stress condition is harmful to the body and may results in many health problems.

The circuit described here is useful to monitor the stress level before and after practicing a relaxation exercise.

http://www.electroschematics.com/wp-content/uploads/2010/02/Stress11.png

PRINCIPLE

The resistance of the skin varies, if the stress level is high the skin offers less resistance and if the body is relaxed the skin resistance is high. During high stress there is increase in the blood supply to the skin, this increases the permeability of the skin.

High stress causes sweating and leakage of water from the blood vessels in the skin. This makes the skin moist and electrical conductivity increases.

CIRCUIT

COMPONENETS

Resistors: 1)R1- 470Ω

2)R2- 1.2 K

3)R3- 470Ω

4)R4- 470Ω

5)R5- 1K

6)R6- 47Ω

7)VR1- 1M

8)VR2- 47K Capacitors: 1)C1- 10µ, 16V

2)C2- 100µ, 16V

3)C3- 100µ, 16V

Semiconductor: 1) IC1- LM3915

2) T1- BC548

3) D1- IN4148

4) ZD1- 5.1V,0.5W

5)Red, Green and Blue LED PZ1- Piezo Buzzer 9V Battery One Way Switch Touch Pads

LM3915

It is a monolithic integrated circuit that senses analogue voltage levels and displays them through LEDs providing a logarithmic analogue display. It can drive up to ten LEDs one by one for each increment of 125 mV in the input.

PIN CONFIGURATION

PIEZO BUZZER

APPLICATIONS

Stress level indicator.

For measuring resistance of skin.

To know mental state of person. In diagnosis of excessive sweating

(Hyperhydroses).

ADVANTAGES

Portable.

Low power consumption.

Low cost.

Highly sensitive to small currents.

DISADVANTAGES

Less accuracy.

Output is not measurable.

THANK YOU