Low Battery Cutoff + Overload/Short Circuit Cutoff + Voltage Feedback Circuit For DIY Inverters

Low Battery Cutoff + Overload/Short Circuit Cutoff + Voltage Feedback Circuit For DIY Inverters

I am sharing a protection circuit for DIY inverters that has 3 functions which are 

1. LOW BATTERY CUTOFF:

The low battery cutoff circuit is a circuit that protects the inverter battery from draining (discharging)

led d4 turns on when the battery is lower than the preset voltage which can be adjusted through a 22kohms potentiometer (variable resistor) 

How does it work?

2. VOLTAGE FEEDBACK:

The feedback system is a circuit that senses the output level (voltage) of a circuit (inverter).

The feedback circuit in this project is compatible with many DIY oscillators (PWM circuits)

e.g SG3524, TL494, SG3525 etc

which can be preset with the help of a 10Kohms  potentiometer (variable resistor) in the VFB section

How does it work?

3. OVERLOAD/SHORTCIRCUIT CUTOFF(CURRENT FEEDBACK CIRCUIT):

The overload/shortcircuit (current feedback) protection prevents circuits from being damaged via overcurrent and shortcircuits In this project the current feedback circuit is a simple one that can be analyzed by anyone with basic electronics.

How does it work?

the shunt resistor is connected in series with the inverter transformer output when a load is connected to the inverter output there will be a voltage drop (build voltage) between the shunt resistor and  the voltage between the 2 pins of the shunt resistor is ac low voltage(1v-5v depending on how much load is connected to the inverter, the higher the load the higher the voltage build between the pin of shunt resistor )

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TERMS used in the schematic below:

VFB (voltage feedback)

LIVE (live output of the inverter)

NEUTRAL (neutral output of the inverter)

OSC+ (to inverter oscillator +)

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