LED Bulb Schematic
Every year the demand for LED bulbs is growing. They may soon displace from the market incandescent and fluorescent counterparts, which can not boast the same safety, last not as long, absorb more electricity and can not be repaired in case of breakage.
The circuit diagram of an LED light bulb is simple for an experienced electrician as well as for a beginner. But the device of LED light bulbs is more complicated than fluorescent light bulbs. If you need to replace the LED, you not only need to understand the circuit of the bulb, but also know how to use a soldering iron, as well as understand how the elements work.
Variety of circuits
The driver is needed to stabilize the voltage and is collected using circuits on capacitors and transformers. The second option is more economical, and the first is needed to create a powerful lamp. In addition, there is another type of circuit - inverter circuits. They are used in the production of dimmable lamps and a large number of chips.
Pulse drivers.
When compared to the linear driver, which uses a capacitor, the pulse driver is characterized by effective protection against instability in the mains. To look in detail at an example of a pulsed diode lamp circuit, we use the CPC9909. The efficiency of this product reaches 98%, so it can be considered without exaggeration one of the most economical and energy-saving.
The device can be connected to high voltage (550V) due to the built-in driver with a stabilizer. This simplified the circuit and reduced the cost of the device.
Connection with a pulse driver is used to activate lighting in case of emergency, and is suitable as an example of step-up converters. At home, based on the CPC9909 driver model, you can build a light that will be powered by batteries or a driver, but the power will not exceed 25V.
Dimmable drivers
With the help of a dimmable driver, the brightness of the LED lamp can be adjusted, allowing you to set the desired level of light in each room, reducing the brightness of the light during the day. Devices are used to emphasize certain interior items.
Dimmer saves energy, because you do not need to turn on the lamp at full power each time you turn it on, which has a positive effect on the service life of the product.
Two varieties of dimmable drivers are used in production. Each has pros and cons. One works on pulse width modulation (PWM). The dimmer is installed between the diodes and the power supply. The circuit is powered by pulses of varying duration. A good example of PWM modulation is a crawl line.
The second type of dimmable drivers affect the power supply. They are widely used for products with the ability to stabilize current. Adjustment can affect the hue of the lighting. If they are white chips, they will begin to glow yellow when the amperage is lowered, blue when the amperage is increased.
Capacitor
The capacitor circuit can be considered one of the best-selling, and is often found in household lights.
The capacitor C1 is needed to protect the device from mains noise. C4 will smooth out the ripple. When current is applied, resistors R3-R2 will limit it and protect the circuit from short circuits. The element VD1 converts the AC voltage. When the current flow stops, the capacitor will discharge through resistor R4. But elements R2-R3 are not used by all LED lighting manufacturers.
To check the functionality of the capacitor, a multimeter is used. The scheme has several disadvantages:
- you can not achieve high brightness of the glow, you will need more capacitors;
- there is a risk of overheating chips due to unstable current supply;
- there is no galvanic isolation, electric shock is possible. When disassembling a light bulb you can not touch the live elements with your bare hands.
Despite the disadvantages, the circuit has many advantages, the lamps sell well. It is easy to assemble, low prices, and a wide range of output voltages. Even craftsmen with a modest amount of experience can try to make a product themselves. To do this, some of the parts can be removed from old TV sets or receivers.
Click here to see: A simple circuit for an LED lamp power supply
LED Tube Voltage
The voltage of LEDs in a lamp is between 110 and 220 volts. These values are achieved by combining several chips. Reducing the voltage and DC is the job of the driver, which is in every bulb.
If it is not there, and the bulb needs to run from the mains, you will need to connect an external device. Not so long ago there were LEDs that run on alternating voltage. But since they pass current only in one direction, they remained in the niche of products that operate on direct current.
