The circuit of a simple 100 watt inverter discussed in this article can be considered as the most efficient, reliable, easy to build and powerful inverter design.
The idea was published many years back in one of the elecktor electronics magazines, I present it here so that you all can make and use this circuit for your personal applications. Let's learn more.
The proposed simple 100 watt inverter circuit disign was published quite a long time ago in one of the elektor electronics magazines and according to me this circuit is one of the best inverter designs you can get.
I consider it to be the best because the design is well balanced, well calculated, utilizes ordinary parts and if done everything correctly would start working instantly.
The efficiency of this design is in the vicinity of 85% that's good considering the simple format and low costs involved.
Using an Transistor Astable as the 50Hz Oscillator
Basically the whole design is built around an astable multivibrator stage, consisting of two low power general purpose transistors BC547 along with the associated parts consisting of two electrolytic capacitors and some resistors.
This stage is responsible for generating the basic 50 Hz pulses required for initiating the inverter operations.
The above signals are at low current levels and therefore requires to be lifted to some higher orders. This is done by the driver transistors BD680, which are Darlington by nature.
These transistors receive the low power 50 Hz signals from the BC547 transistor stages and lift them at higher current levels so that it can be fed to the output transistors.
The output transistors are a pair of 2N3055 which receive an amplified current drive at their bases from the above driver stage.
2N3055 Transistors as the Power Stage
The 2N3055 transistors thus are also driven at high saturation and high current levels which gets pumped into the relevant transformer windings alternately, and converted into the required 220V AC volts at the secondary of the transformer.
Parts List for the above explained simple 100 watt inverter circuit
R1,R2 = 27K, 1/4 watt 5%
R3,R4,R5,R6 = 330 OHMS, 1/4 watt 5%
R7,R8 = 22 OHMS, 5 WATT WIRE WOUND TYPE
C1,C2 = 470nF
T1,T2 = BC547,
T3,T4 = BD680, OR TIP127
T5,T6 = 2N3055,
D1,D2 = 1N5402
TRANSFORMER = 9-0-9V, 5 AMP
BATTERY = 12V,26AH,
Heatsink for the T3/T4, and T5/T6
- Power Output: 100 watts if single 2n3055 transistors are used on each channels.
- Frequency: 50 Hz, Square Wave,
- Input Voltage: 12V @ 5 Amps for 100 Watts,
- Output Volts: 220V or 120V(with some adjustments)