Enhanced Heat Dissipation Performance of Automotive LED Lamps Using Graphene Coatings

Graphene heat-dissipating coating (GNHC) of 0.6 wt % GN concentration is utilized to promote the cooling performance of automotive light-emitting diode (LED) lamps. Three cases are studied as follows: Case 0 is the original automotive LED lamp as the baseline. Case 1 is to apply GNHC to reduce the thermal resistance of the junction surfaces between the components of automotive LED lamps. The aluminum fin radiator of Case 1 is further coated with GNHC on the surface that becomes Case 2. The spectrum, illuminance, power consumption, and surface temperature are measured at different ambient temperatures (Ta) to fully evaluate the feasibility of applying GNHC to improve cooling performance and the impacts on the related characteristics of automotive LED lamps. The results show that the maximum illuminance efficacy of Case 1 and Case 2 with high beam, irradiation angle of 0 degrees, and Ta of 80 °C is 11.03% and 8.70% higher than that of Case 0, respectively. The minimum temperature difference of heat dissipation path of Case 1 and Case 2 with high beam, irradiation angle of 90 degrees, and Ta of 80 °C is 6.41% and 5.33% lower than that of Case 0, respectively, indicating GNHC as a promising coating material for improving the cooling performance of automotive LED lamps.

PLATEAU FORMATION ON ACCELERATING WAKEFIELD FOR ELECTRON-WITNESS-BUNCH AND ON DECELERATING WAKEFIELD FOR DRIVER-BUNCHES IN A PLASMA

Plasma wakefield acceleration promises compact sources of high-brightness relativistic electron and positron beams. Applications (particle colliders and free-electron lasers) of plasma wakefield accelerators demand low ener-gy spread beams and high-efficiency operation. Achieving both requires plateau formation on both the accelerating field for witness-bunch and the decelerating fields for driver-bunches by controlled beam loading of the plasma wave with careful tailored current profiles. We demonstrate by numerical simulation by 2.5D PIC code LCODE such optimal beam loading in a linear and blowout electron-driven plasma accelerator with RF generated low and high beam charge and high beam quality.

Automatic (Headlight) Beam Controlling module for two-wheelers

Automatic High Beam controller is a device made due to the rising number of accidents at night because of LED headlamps temporarily affecting the vision of the driver on the opposite lane. According to AAA, LED lights do a much better job of illuminating the roadway, particularly in the low-beam application versus a halogen reflector at 150 feet more during testing. But, still, that brings the max vehicle speed to about 52 miles an hour, which is still falling short of highway speeds. So, the users are suggested to drive with high beam on if there is no oncoming traffic within a reasonable distance and the roadway is improperly lit. But in practice most people drive with the high beam settings in places with or without traffic great from the user's standpoint. However, even on low beam, they have such a high intensity that on 2-lane roads, especially when the oncoming driver of a car or small pickup approaches the LED equipped truck at night, in rain, fog, or snow the oncoming driver is blinded at a level equal to or greater than if the LED equipped vehicle were using conventional halogen high beams. This device is made without distance or ambient lighting being deciding factors and entirely based on user’s discretion. The transmitter model is fitted with a button that sends a signal to the receiver model using nrf24L01 modules and AT Mega 8 microcontroller (programmed using Arduino UNO). The pressing of button causes the state of the button to be set to HIGH. This signals the receiving circuit to set the LED pin to LOW. Therefore, the High Beam is set to Low Beam for 5 seconds when the impulse is received. Due to the use of H4 C6 headlamps which are rated for 36W with a minimum power requirement of 12W an adapter was connected to convert 220V AC supply to 12V, 3A DC supply for the LED and the rest of the circuit.