Voltage Supply Inverter Using IC 555

SUMAN HOSMANE

SURAJ DONTHI

Intro

Whats a power sopply???

A power supply is used to convert an input electrical energy to the required

electrical specifications of a loadIn our mini project we have used a

variable power supply….

Classification

AC Power Supply

DC Power Supply

AC Power Supply

DC Power Supply

Common Sources Batteries, Thermocouples, solar cells,

dynamo…..

Voltage Invertors

•Extensively used in the analog domain

•Most circuits incorporate voltage invertors

•Generally as dual power supply

Few Commonly used Inverters

◊ICL 7660

◊Op-amp sign changer/inverter

◊IC555 timer in astable multivibrator mode.

IC 555 Timer

Extensively used in pulse generation,

PWM, oscillators, time delays

Pin Layout

Internal Structure

Modes

Astable mode

Bistable mode

Monostable mode

The Astable Mode

DC to AC

Produces square waves at Vo

Produces square waves at Vc

Circuit Diagram

Time Calculation

Avoid low values of R1 so that o/p is saturated0V-2/3 Vcc in 1st cycle1/3-2/3 Vcc in subsequent cycles

Astable Multi Vibrator as Voltage Inverter

During +ve half cycle:◦The diode eliminates the -ve DC component

◦Fed to the –ve potential line to convert to –ve

During –ve half cycle:The –ve voltage is let out through the diode D2 as it is.

Working

Overall O/P

Finally the th o/p is got across the 100uF Capacitor at V0

The o/p is slightly smaller.

Calculation The output frequency of the circuit constructed is given by the   f = 1.449 / [(4.8+66)* 10^3 * 22 * 10^-6] f = 1.449 / 1.5576 f = 0.93 Hz

Duty Cycle

T on = 0.693(Ra + Rb) C = 0.693 (4.8 + 33) * 10^3 * 22 * 10^-6 = 0.57629s   T off = 0.693(Rb) C = 0.693 (33 * 10^3) (22 * 10^ -6) = 0.593s

Advantages

Used to run op amp which requires Vcc and –Vcc for its working. Circuits that require both negative and positive voltages for their working can incorporate such circuits. Eg:

Reference

CicuitsToday

Thank U