Latin America. Dielectric has developed a new eco-friendly charging solution that reduces costs and features a closed-loop cooling system that protects RF system components from failures that can cause major damage to the transmission system and shelter.
Showcasing at the 2024 NAB Show, OptiLoad breaks new ground by using programmable logic controls (PLCs) to detect rising RF temperature and power levels, awakening the system to act. OptiLoad PLCs also monitor the status of circulation pumps and demand-driven fans that are activated to address RF flow and temperature increases.
The OptiLoad design includes a water column load that Dielectric has offered for two decades, with more than 5000 units shipped worldwide. Using the water column load as a basic component, Dielectric has added a built-in heat exchanger that responds to PLC activations. Water column charging can operate without coolant flow or activated fans with power outputs of up to 5kW. This ensures plenty of clearance when RF is detected and the coolant and fans start running before the charge reaches 5 kW.
The entire SNMP-enabled system is centralized in a compact cabinet on wheels that can be quietly located in a corner and easily moved to a new space in the facility as transmission systems are redesigned. SNMP functionality will allow the transmitter to perform a daily handshake. If that handshake does not occur, the station will be notified to prevent failures.
"OptiLoad's modern design is a true convergence of passive RF, electronics and sensing equipment that our engineering team brought to life," said Keith Pelletier, president of Dielectric. "This says a lot about the future of the RF business. For our customers, it fixes all-too-frequent RF string failures and gives them peace of mind knowing they have a solution they don't need to worry about. OptiLoad was customer-driven, and we listened to their concerns about reliability and required features."
Pelletier explains the importance of passive RF charging and a closed-loop system in the design of OptiLoad. This will prevent the refrigerant from becoming contaminated and causing failures within the charge that would eventually cause RF piping failures to the combined system. Once charging fails, other components will fail as well if they aren't detected early enough. "Once the refrigerant stops working or no longer flows through the pipes, failure and damage are imminent. In some cases, entire systems need to be replaced, and cleaning services may be required to remove coolant from floors. It can quickly become very expensive."
Use case scenarios
OptiLoad can be used in multiple scenarios. For high-power TV systems, OptiLoad takes on the role of charging solution for the transmitter combiner rack. In this scenario, the typical RF power reaching the load is very small or non-existent. "OptiLoad brings value here because when amplifiers fail in a transmitter rack, it causes a power surge in the load," Pelletier said. "The more amplifiers fail, the greater the amount of RF power within the load."
In traditional RF TV systems, independent charging requires a constant flow of refrigerant moving through the system to prevent catastrophic failures. OptiLoad's logic controls only apply power to the fans, releasing coolant flows through the load as needed. This makes OptiLoad a very eco-friendly solution, as the load remains off 95 percent of the time. When a power imbalance occurs, OptiLoad protects the entire RF chain until the amplifiers can be replaced or repaired. Once repaired, OptiLoad remains inactive until prompted again.
OptiLoad is also ideal as an RF troubleshooting tool. In this second scenario, engineers can use OptiLoad as a station load when they need to test the transmitter or isolate the transmission line and antenna to identify and resolve a problem. As in the first scenario, OptiLoad only kicks in and boosts to full power if the load is being used, offsetting electricity costs and reducing the station's energy bills.
OptiLoad further protects the broadcaster's RF investment through various operating modes. It will go into standby mode with no RF power present when the coolant temperature is below 130 degrees. OptiLoad initiates flow from the high-efficiency circulator pump when temperatures reach between 130 and 150 degrees; The fans kick in when the temperature rises from there.
"OptiLoad turns on the moment it detects the presence of RF and ramps up from there using variable-speed fans and adjusting coolant flow rates," Pelletier said. "This is the first system of its kind to recognize the presence of RF, which simply makes it the safest protection option on the market.
As a closed-loop system, the coolant circulates strictly within the OptiLoad to keep the liquid fresh. We've also simplified the overall design, favoring a minimal number of connections to ensure coolant lines run consistently and flawlessly. Basically, we eliminate all leak points and address all activations necessary for system protection to ensure that RF shelter floors remain dry and passive RF parts remain intact for future use."
