The Simplest Circuit

The strength supply routine structure is developed as a resource of continuous present with adverse heat range coefficient. Transistor Q1 (BD 140) is used as a heat range indicator. transistor Q2 is used to avoid the strength supply from discharging through R1 when strength is out of stock. Getting routine is developed depending on the LM350 present regulator IC. The result present of the battery charger can be altered between 13-15 V by various the POT R6.

LM350 will try to keep the present decrease between the feedback pin and result pin at a continuous value of 1.25V. So there will be a continuous present circulation through resistor R1. Q1 act here as a heat range indicator with the help of R6/R3/R4 elements that are more or less manages the platform present of Q1. As relationship emitter / platform of transistor Q1, the same as other semiconductors, containing the heat range coefficient of-2mV / ° C, the present result will also display a bad heat range coefficient. This one is just a aspect of 4 huge, because the difference of the emitter / platform of Q1 is increased by a aspect of category P1/R3/R4. This causes some-8mV / ° C. LED will lighting whenever strength is available.

The battery circuit scheme is designed as a source of constant voltage with negative temperature coefficient. Transistor Q1 (BD 140) is used as a temperature sensor. transistor Q2 is used to prevent the battery from discharging through R1 when electrical power is unavailable. Charging circuit is designed based on the LM350 voltage regulator IC. The output voltage of the charger can be adjusted between 13-15 V by varying the POT R6.

LM350 will try to keep the voltage drop between the input pin and output pin at a constant value of 1.25V. So there will be a constant current flow through resistor R1. Q1 act here as a temperature sensor with the help of R6/R3/R4 components that are more or less controls the base current of Q1. As connection emitter / base of transistor Q1, the same as other semiconductors, containing the temperature coefficient of-2mV / ° C, the voltage output will also show a negative temperature coefficient. This one is just a factor of 4 large, because the variation of the emitter / base of Q1 is multiplied by a factor of division P1/R3/R4. This leads to some-8mV / ° C. LED will light whenever power is available.

Here this is a simplest circuit for 100 watt inverter for generating 220vAC from 12vDC. I say simplest because here in this inverter circuit a minimum number of components are used to design the schematic, which is quite difficult to make a circuit like this with further fewer components.

100 watt inverter schematic diagram

Fig: Schematic diagram of 100W inverter

This 100W inverter circuit works great for small loads like a fan or 2-3 bulbs/lamps. In this circuit as IC1 we used a CD 4047 IC to generate 100Hz frequency (180 degree out of phase). CD 4047 IC is from Texas Instruments. It is mostly used as Astable/Monostable signal generator device. In this circuit it is triggered as astable multivibrator by the capacitor C1 between the Pin 1 and 3 of CD4047. And VR1 is used to adjust the frequency of signal.

Four 2N3055 transistors are used to amplify the pulse trains that are pre-amplified by two TIP122 transistors. There used three transistors for each side (half cycle), one TIP122 & two 2N3055 transistor to drive the output transformer (TX in circuit). Four 2N3055 transistors are used as driving transistor. An inverters maximum output power depends on two factors; one is the max current rating of transformer’s primary winding and other factor is the current rating of driver transistors.

Transformer: Use a 12v-0-12v, 10A step-down transformer in reverse. That’s mean secondary winding (12v-0-12v) will be the primary and primary winding (220VAC side) will be the secondary (output). So that it will worked like a step-up transformer. You can also use a 5A transformer instead of 10A, if you couldn’t have 10A.  But the output power will decrease to 60 Watt.

+12VDC: A good quality 12V car battery could be used for DC 12V.

Parts list of 100watt inverter: