Electronic ballast for automotive high intensity discharge lamps

lulu91

Electronic ballast for automotive high intensity discharge lamps [Copy link]

Metal halide high-intensity discharge lamps, commonly known as HID, can be applied to many fields, especially in automotive lighting, which can effectively reduce accidents and benefit mankind. Existing low-voltage HID electronic controllers generally have problems such as old-fashioned style, large size, many components, few functions and protection functions, low safety and reliability, and inconvenient installation and use: 1) When used in installation or testing, the "+, -" polarity is accidentally connected in reverse, or because cars in some parts of the world are positively grounded, it is easy to cause burns to the wires in the car, and in severe cases, it will catch fire and burn the controller because this product has a reverse protection circuit; 2) When the power supply or the car generates electricity, the voltage regulator tube is unstable or the power is too low. The battery capacity is reduced, resulting in a rise in the voltage of the entire vehicle, which is easy to burn. When the user stops the generator but forgets to turn off the light, the battery is almost exhausted, the voltage drops, and there is insufficient voltage when the car engine starts next time; 3) Since the instantaneous output ignition voltage is as high as 23KV at startup, when the bulb is burned out or damaged and cannot be lit, when the output wire is disconnected or damaged, and when there is no bulb installed, there will be a risk of sparking, which may cause fire in the car or people in the car to be injured. Some users accidentally damage the output wire during installation, causing a short circuit, which will burn out and the fuse will burn out; 4) When the bulb begins to age or the bulbs of different brands have obvious parameter errors, the bulb will work unstably.

The purpose of this design is to provide an electronic controller for high-intensity gas discharge lamps that is easy to install and use, safe, reliable, and fully functional.

The technical solution (Figure 1) is: a booster, A/C converter and high-voltage ignition are connected in sequence behind the DC power supply. The output end of the high-voltage ignition is connected to the HID high-intensity gas discharge lamp, and a reverse protection circuit is set between the DC power supply and the booster.

The electronic controller of the high-intensity gas discharge lamp also includes a control and protection module, which includes a switch tube, a pulse width modulator and an undervoltage and overvoltage protection circuit. The switch tube is connected in series to the primary coil of the booster, the control end of the switch tube is connected to the output end of the pulse width modulator, the input end of the undervoltage and overvoltage protection circuit is connected to the output end of the DC power supply for sampling, and the output end of the undervoltage and overvoltage protection circuit is connected

to the input end of the pulse width modulator. The control and protection module also includes an open circuit and short circuit protection circuit, the input end of the open circuit and short circuit protection circuit is connected to the output end of the booster for sampling, and the output end of the open circuit and short circuit protection circuit is connected to the input end of the pulse width modulator.

This control and protection module also includes a ballast tracking circuit, the ballast tracking circuit samples the voltage from the output end of the booster and the current from the A/C converter, and the output end of the ballast tracking circuit is connected to the input end of the pulse width modulator.

A filter network is provided between the DC power supply and the booster, and between the A/C converter and the high-voltage ignition, and the output end of the DC power supply is connected to the power indication circuit.

This design has the following advantages:
· A reverse protection circuit is set between the DC power supply and the booster. Even if the "+" and "-" polarities are accidentally connected in reverse during installation or testing, the circuit will be automatically cut off to protect the circuit.
· Undervoltage and overvoltage protection circuits are set: When the voltage of the vehicle rises after power supply or vehicle power generation due to unstable voltage regulator or reduced battery capacity, it will automatically power off to protect the vehicle when it reaches 16V. However, it will automatically restart when the voltage drops. When the user stops the generator but forgets to turn off the light, and the battery is nearly exhausted, the voltage drop will automatically power off to protect the battery to ensure that the battery can save enough energy for the next engine start. When some users turn on the light to start the generator, the starter motor suddenly consumes a lot of current, causing the battery voltage to drop, and it will protect and shut down. When the generator starts, the voltage returns to normal, and this circuit will immediately return to normal operation.
·Since the instantaneous output ignition voltage is as high as 23KV at startup, when the bulb is burned out or damaged and cannot be lit, when the output wire is disconnected or damaged, or when there is no bulb installed, there will be a risk of sparking, which may cause fire in the car or people in the car to be injured. Therefore, this circuit is equipped with an open circuit and short circuit protection circuit, which automatically cuts off the power supply when open circuit, short circuit and leakage occur.
·Real-time tracking of the working status of the bulb is realized. When the bulb begins to age or the bulbs of different brands have obvious parameter errors, this circuit also makes it work stably, through voltage monitoring and current monitoring, and sends the detection signal to the pulse width modulator to change the pulse width to achieve the purpose of ballast.
·Equipped with LED power indicator light, when the power is on, the LED automatically lights up, and when the power is off, the LED goes out, which is more intuitive and convenient to use.

Figure 1 Automobile high-intensity discharge lamp electronic ballast circuit

As shown in the circuit block diagram, this circuit includes a booster 2, an A/C converter 3 and a high-voltage ignition 4 connected in sequence behind a DC power supply 1, the output end of the high-voltage ignition 4 is connected to a HID high-intensity gas discharge lamp 5, and a reverse protection circuit 6 is also provided between the DC power supply 1 and the booster 2. The utility model circuit also includes a control protection module, which includes a switch tube 8, a pulse width modulator 9 and an undervoltage and overvoltage protection circuit 10. The primary coil of the booster 2 is connected in series with the switch tube 8, the control end of the switch tube 8 is connected to the output end of the pulse width modulator 9, the input end of the undervoltage and overvoltage protection circuit 10 is connected to the output end of the DC power supply 1 for sampling, and the output of the undervoltage and overvoltage protection circuit 10 The end is connected to the input end of the pulse width modulator 9, the control protection module also includes an open circuit and short circuit protection circuit 7, the input end of the open circuit and short circuit protection circuit 7 is connected to the output end of the booster 2 for sampling, the output end of the open circuit and short circuit protection circuit 7 is connected to the input end of the pulse width modulator 9, the control protection module also includes a ballast tracking circuit 12, the ballast tracking circuit 12 samples the voltage from the output end of the booster 2 and samples the current from the A/C converter 3, the output end of the ballast tracking circuit 12 is connected to the input end of the pulse width modulator 9, the circuit also includes a power indication circuit 13, the power indication circuit 13 is connected to the output end of the DC power supply 1, and a filtering network is arranged between the DC power supply 1 and the booster 2, and between the A/C converter 3 and the high-voltage ignition 4.

nm85

nice one

wangqingtao

Very good!!!

2345

Haha, it's a very practical design, but I'm still a little worried about modifying it myself. Thanks for sharing.

bignight

You have to learn this stuff well.

yqy1231988

Good stuff~~