In this article, we explained how the inverter bulb or emergency bulb works and also we shared the circuit of inverter bulb. So you can try and make your own DIY emergency bulb
An inverter bulb is essentially an emergency LED bulb. Actually, such products are somewhat confusing because there is no inversion process (DC to AC, or vice versa) involved in the circuits where these are used.
The technology used in these bulbs enables them to automatically turn on the LED light during a power cut and automatically charge the internal battery when AC mains is available.
Also check: Which Current is more Dangerous AC or DC?
Basically, an inverter LED bulb is a two-in-one bulb. That is, when there is AC mains power, it works as a normal light bulb but when there is a power cut, it works as an emergency light bulb.
Most inverter LED bulbs have lithium-ion batteries that provide three- to four-hour backup. These internal batteries require three to four hours of charging time to fully charge.
Thereafter the charging voltage is automatically cut to protect the battery from getting overcharged. The bulb is designed to charge the internal battery even during normal operation.
However, most inverter LED bulbs come with a charge-only mode. This mode is used to charge the internal battery with the LED bulb off.
When AC mains power goes off, this inverter bulb automatically switches on to act as a DC emergency light. It can be switched off when not required.
The features of an inverter LED bulb include fully automatic control, low power consumption, and high efficiency. Since it has an internal backup power source and electronic control circuit, it can detect the switch state even during a power cut.
Inverter Bulb Circuit Construction
The circuit would contain the following components:
- A battery (such as a 12V lead-acid battery or a 3.7V lithium-ion battery) to provide backup power
- A DC-DC converter (also known as a boost converter) to step up the voltage from the battery to the voltage needed to drive the LED bulb
- An inverter circuit to switch the bulb between using main power and battery power
- A switch to manually select between battery power and main power
- A charging circuit to charge the battery when main power is available
The main power would be connected to the input of the inverter circuit and the output of the inverter circuit would be connected to the input of the DC-DC converter. The output of the DC-DC converter would be connected to the LED bulb.
The switch would be connected in parallel with the main power input to the inverter circuit. The charging circuit would be connected to the battery and the main power input.
When the main power is available, the inverter circuit would supply the main power to the LED bulb, and the battery would be charged by the charging circuit. When the main power is lost, the switch would be flipped to activate the inverter circuit, and the battery power would be supplied to the LED bulb through the DC-DC converter.
Inverter Bulb Working
An emergency inverter LED bulb contains a small battery and an inverter circuit. When power is lost, the inverter circuit switches the bulb over to battery power.
The LED bulb will continue to function as normal, using the battery power as its source until power is restored, at which point the inverter circuit switches the bulb back to using the main power source.
This allows the LED bulb to continue functioning as an emergency light during power outages.
Recommended: You can check this video to understand what is inside the emergency rechargeable inverter LED Bulb.
