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
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