- It shuts down the inverter and also provides audio-visual indication of the overload condition.
- after shutdown, it automatically restarts the inverter with a delay of 6 seconds. thus, it saves the user from the inconvenience caused due to manually resetting the system or running around in darkness to reset the system at night.
- It permanently shuts down the inverter and continues to give audio warning, in case there are more than three successive overloads. Under this condition, the system has to be manually reset.(Successive overload condition indicates that the inverter output is short-circuited or a heavy current is being drawn by the connected load.)
Please note the following points carefully:
- Points A and B at the input of IC2 should be connected to the corresponding points (A and B respectively) across the ammeter.
- Points C and D on the relay terminals have to be connected in series with the already existing ‘on’/‘off’ switch leads of inverter as shown in Fig. 1. this means that one of the two leads terminated on the existing switch has to be cut and the cut ends have to be connected to the pole and N/O contacts respectively of relay RL1.
- The ammeter should be connected in series with the negative terminal of the battery and inverter, as shown in Fig. 2.Move the wiper of preset VR1 to the extreme position which is grounded. Switch ‘on’ the inverter. For a 300W inverter, connect about 250-260W of load. Now adjust VR1 slowly, until the inverter just trips or shuts down. repeat the step if necessary. Use good-quality preset with dust cover (e.g. multiturn trimpot) for reliable operation.the circuit can be easily and success-fully installed with minimum modifications to the existing inverter. all the components used are cheap and readily avail-able. the whole circuit can be assembled on a general-purpose PCB. The cost of the whole circuit including relay, buzzer, and PCB does not exceed Rs 100.
Author : Siddharth Singh - Copyright : EFY Mag