Water Cooled LEDs

High-Intensity Water-Cooled LEDs

(Product ID: LM2XX-*, DC2XX, PUL2XX)**

Water-cooled LEDs are necessary in large wind tunnels and in applications where higher light intensity is needed, like fast PSP. The water-cooling allows the LEDs to be driven harder than the air-cooled systems. The system is composed of a control box, which houses the drive electronics, power supply and water-circulation system, the LED head and an umbilical cable linking the LED head to the control box. There are two water-cooled LED system options

1.) The continuous 2-inch, water-cooled LED light source provides uniform, stable illumination, for pressure and temperature sensitive paint measurements. The unit operates continuously or in long-pulse mode, designed for radiometric systems by connecting to the DC2XX driver box (module for radiometric). The operation mode is set sending an external TTL trigger pulse to the DC2XX to set the output pulse width and frequency. The duty cycle may be set from 0% to 100%.

2.) The lifetime 2-inch, water-cooled LED light source provides uniform, stable illumination for lifetime pressure and temperature sensitive paint measurements. The system is overdriven and designed for lifetime acquisition systems by connecting to the PUL2XX driver box (module for lifetime). Overdriving the unit gives a higher peak power per pulse than the continuous LED system. Because it is overdriven, the duty-cycle is limited to 5%. Operation is controlled by applying a TTL signal to the external BNC on the PUL2XX module. The maximum pulse width is limited to 1-ms. The PUL2XX has a built-in safety circuit to protect the LED head if the duty-cycle limits are exceeded.

The light distribution from either system is approximately Gaussian for distance greater than 18-inches [45-cm] from the source. The units are available in 400-nm and 460-nm packages, however, other wavelengths are available upon request. These units surpass the performance of the 2-inch, air-cooled LED systems as they offer a significant increase in power. Maximum input pressure to the control box is 90 psi. An external water source is required to cool the LED module. The control box contains a flow meter and safety circuit to shut off power to the LED if the flow rate is too low or the LED approaches overheat temperatures.

Ordering Information:

Continuous LED System: LM2XX-*** (LED head with umbilical) + DC2XX (DC/long-pulse control box and driver with power supply).
Lifetime LED System: LM2XX-*** (LED head with umbilical) + PUL2XX (Over-driven control box and driver with power supply).

**Note: “-***” denotes wavelength for LED heads.

The water-cooled LED systems are compatible with the parabolic reflector and diffuser for focusing the output.

Water-Cooling Schematic:

An external water source needs to be supplied to the control box. This can be tap water, so long as it is filtered and clean. A refrigerated chiller can also be used. Chillers with positive displacement pumps should be used. Chillers with centrifugal pumps do not have the required pressure for use with the water-cooled LEDs. In refrigerated chillers, only distilled water should be used.