Hello Engineers. Inverters are a necessity in areas with a load shed or powercuts. Also necessary in offices, shops, etc. So that the day to day electricity requirements can’t be interrupted. Today I am going to discuss a 150 watts inverter circuit using CD4047 IC. This is a stable square wave inverter circuit for powering AC devices like table fans, CFLs, Tube lights, TV (LCDs or LEDs only). This inverter circuit using CD4047 IC is a stable square wave design with a much cleaner and stable waveform than the other transistor inverters. So let’s go further with understanding and making our 150 watts Inverter circuit using CD4047 IC.
Block diagram / Basic design of an inverter circuit
Above is a block diagram showing the basic concept of the working of an inverter. For understanding, the work of each element or component of an inverter, click to read this article. And know the basic working of an inverter and types of inverters.
Circuit Diagram for Inverter Circuit Using CD4047
Materials and components
- IC CD4047B
- VR1 250K pot -1pcs
- C1 0.02uf or 0.01uf – 1pcs
- R2&R3 100R(100 Ohm) 1 watt – 1pcs
- Q1 & Q2 IRF540N MOSFETs – 2pcs
- Transformer 12-0-12 10A – 15A Transformer( for voltage step-up)-1 pcs
- 12V 20 Ah Lead Acid battery | 10 ah for 100 watts
- 16 pin DIP connector
- Misc ( Digital multimeter, soldering iron, PCB)
- Separate standard size Heat Sinks for MOSFETs
The main components of this circuit design are IC CD4047, IRF540N Mosfets and 12-0-12 15A transformer for voltage step-up( usually called step-up transformer as used reversed).
CD4047 IC: This is a 16 pin multivibrator IC designed by TEXAS Instruments that have a very low power consumption. This IC can operate in astable or multivibrator mode in free-running or gateable topologies. Here, it can generate a 50% duty cycle that is used for the inverter circuit.
CD4047 have a number of applications like frequency generators, Timer circuits, inverters ( modified sinewave as well as squarewave).
The circuits here use CD4047 IC as an astable multivibrator ( free-running oscillator). There is a capacitor between pin 1 and 3. A variable resistor of 250k is connected to the pin2 (Rxx) to set the frequency of the IC.
Outputs are from pin 10 and pin 11. Pins 10 and 11 outputs are going to the gates of MOSFETs for amplification through 100ohm resistor. 100ohm resistor protects the IC and MOSFETs both.
The high-speed switching of MOSFETs generates the current and power is then amplified to drive the transformer. Here, in the circuit, its mentioned to use 15Atransformer for 150watts power output with a suitable battery.
The backup of the output depends on the battery’s ah value as well as the load power requirements.
For eg battery is 12v 20ah with 15A transformer and load is 50w, the total power by the battery is 240 watts but the transformer provides 150w. The max time 50watts load can run over 240w backup is 4.8 hours.
Important Keynotes for inverter design and construction :-
I am mentioning some very important notes to calculate output power and backup time.
- Total INPUT POWER = OUTPUT POWER(backup)
- OUTPUT POWER = VOLTAGE*O/P CURRENT across device
- Backup time depends upon Battery ah value as,
- Total available battery backup power(Ah*Vin) / load power requirement = backup time(in hours)
- Output VOLTAGE INCREASES as the CURRENT DECREASES but power remains the same supplied by the transformer.
- Output power is dependent over MOSFETs used for each stage, Total bearable transformer power V*A and of course battery power input.
- STEP-UP TRANSFORMER: A step-up transformer is a stepped down transformer used in a reverse manner. This means the secondary side used as primary and primary used as secondary. Just a transformer for inverter purposes is used in a reverse connection. And, usually have higher amps rating like 5 amp,10 amps,15, or even 25 amps, etc.
I hope you guys liked the circuit as well as the explanation of each stage. Please do mention your views in the comments. Thanks.