Microwave LED Driver Part 2
After Part 1, the LED lighting in the microwave oven was not providing enough illumination. With the LED ribbon left over from the first project, I designed replacement modules that would be better color matched and provide more light.
To control the current delivered to LEDs, an external driver is necessary. The LED driver controls the voltage and current to match the needs of the individual LED in order to maximize the LED’s light output and minimize damage to the LED’s junction temperature.
Detection Area
A microwave powered LED driver is a big dog in the lighting department but it doesn’t have to be. Despite its limitations, this octavetically crowned machine can still put a smile on your face at a reasonable price. The best part is it does it all while putting the occupants of your oh so shiny office on a happy dance. Using the right technology paired with the right people you will be able to see your office with a clear conscience and save on those costly utility bills.
Detection Sensitivity
Detection sensitivity is the ability of a sensor to accurately detect movement within its detection zone. This is an important factor for LED tubes that have microwave occupancy sensors integrated into them.
This type of motion sensor emits a high frequency (HF) 5.8 GHz signal and measures the reflection as it bounces off a moving object. The sensor then transmits a preset dimming control signal to the driver when this measurement reaches a preset threshold.
PVTECH’s motion sensor LED tube has a detection distance of up to 10 meters and will stay lit as long as it senses a movement within its range of sensitivity. The tube will automatically switch to standby mode and the light will be dimmed based on a preset percentage of brightness after a time delay of 20 seconds when it is no longer sensing movement within the area.
The sensitivity can be adjusted to adjust the detection area for a specific application. For example, if a customer wants to use the microwave LED driver in a warehouse with a large metal roof, it is important to reduce the detection area so that no false triggers occur.
In addition, the sensitivity of the microwave sensor will be affected by the materials it is microwave led driver installed in, such as plastic and glass. These materials will reduce or block the sensor’s ability to detect movement and cause a false trigger.
To help avoid this issue, it is recommended that the detector be installed in a location that does not have thicker materials such as glass and plastic, where the microwave radiation may be absorbed. Also, it is important to install the sensor on a flat surface so that it does not pick up vibrations from other nearby devices, such as fans and DC motors.
Corridor Function
Corridors in commercial buildings provide a safe, flexible and efficient way to move around. They also play a vital part in partitioning different spaces, such as office areas and central lobbies. CP Electronics has a range of corridor lighting control solutions that are designed to meet specific project demands from physical space constraints to installation deadlines and budgets.
A microwave led driver with a corridor function has a built in microwave motion sensor and daylight sensor which automatically switches the LEDs on or off based on the ambient light level and motion detected by the microwave sensor. The device also has a time delay which is set on site to suit the requirements of the customer.
When there is no movement the LEDs switch off after a pre-set hold time and gradually decrease to a 10% level saving up to 60% of energy usage. Corridor function is an easy to install and cost effective solution for LED lighting installations in corridors and other areas of the building that do not require constant light.
Luminaire models that feature a corridor function are available with an internal microwave sensor or can be externally mounted with a remote controlled microwave sensor (Part: HLBMS-RC). The remote control option makes it easy to change settings without gaining access to the fitting itself.
The OSRAM range of DALI ed2 compatible LED drivers can be activated for the corridor function using T4T software. This is a great way of achieving more control and savings on energy costs in large open plan offices.
Vitesse modular is a 2-way to 16-way modular wiring system that offers greater customisation enabling step down illuminance and pre-set configurations that are important in corridor lighting control. This gives you the flexibility of a standalone strategy, but introduces more distributed control and allows for customisation through pluggable wiring formats.
Dimming Level
Dimming refers to a process whereby an LED driver reduces the amount of energy that flows through its output circuit to its LEDs. This reduction in power can be achieved by either increasing or decreasing the output current to each LED.
Typically, there are two methods used by LED drivers to do this: pulse width modulation (PWM) or amplitude modulation (AM). PWM uses short on/off pulses to increase and decrease the voltage that flows through the LED output circuit. This results in reduced flicker. This is a good technique for low-brightness dimming as long as the LED driver has a closed-loop bandwidth that can handle high switching frequencies.
AM is also a popular approach. It involves the driver simply changing the current flow to each LED in order to decrease their brightness and eliminate any risk of flicker. However, some LEDs may change colour slightly if the current to them is increased or decreased too much.
When designing a dimming circuit, it is important to determine the total power load of each LED supply. This will help you microwave led driver calculate the maximum power rating of your LED driver. The maximum load should be 20-30% higher than you need to ensure that the driver has enough headroom to withstand unexpected overloads.
The dimming level of the LEDs is dependent on a number of factors including the type of driver being used, the input voltage and the number of lights being dimmed. The best way to get an idea of the dimming level of your LEDs is to use a light meter.
Most microwave led drivers have the ability to be dimmed using a 1-10V control signal, PWM signal or a simple resistance. For example, all MEAN WELL HLG and ELG series drivers can be dimmed to zero% by connecting a 0-10V dimming potentiometer in place of the mains supply.