Energy resistors are utilized in energy era and distribution, control techniques, and other electricity program apps. Illustrations incorporate load financial institutions, grounding resistors, and dynamic braking resistors.
There are numerous potential production strategies but resistors based mostly on thick movie technology substrates provide high integration density that can make it excellent for purposes exactly where higher power dissipation is essential in a modest area. The substance characteristics of the substrate imply it is an excellent match with the aluminium materials in heatsinks and it is chemically inert and mechanically steady.
Particular carrier materials, this kind of as Silicone Nitrite may be utilised to make a power resistor in the kW variety. However, these components can be expensive and could price as a lot as € two hundred every in order portions of a couple of thousand units, in addition the fees for processing with Thick Film components. This implies such resources are normally only used for specialists programs.
Illustrations consist of a electrical power resistor with dimensions one hundred mm by fifty mm on 1 mm thick Alumina Ceramic that can handle five hundred W offered the element temperature is kept constant at about sixty °C. Resistor load financial institutions with energy rankings as high as twenty five kW @ one hundred forty kVolts could be manufactured.
When manufactured correctly utilizing acceptable materials Thick Film power resistors can manage a number of kW of energy dissipation but they generate big quantities of warmth which will fracture the resistor provider plate if not kept under control. Careful thought of the application and thermal administration is consequently essential before committing to the resistor layout and manufacturing process.
One remedy to the resistor thermal overload problem is to submerge the energy resistor in substantial quality mineral oil in a heat exchanger. The exchanger should be designed appropriately to make certain it is capable of taking away the warmth created so the oil temperature is retained continuous at a secure amount.
Proper administration of the warmth exchanger is required as Impurities in the sort of carbon deposits are produced in large voltage oil cooled programs and except if oil is filtered and / or or else retained at substantial top quality via regular replacements, these kinds of impurities will develop to a stage exactly where 1 or a lot more resistors are shorted out of the loop and as a result cause other resistors in the chain to overload and fracture. Annually oil modifications are for that reason advised.
A power resistor produced employing thick movie technology offers a reasonably reduced price, higher functionality, small footprint solution for a broad selection of electricity purposes. Nevertheless, careful thing to consider of thermal troubles is necessary during the design stage to make certain dependable operation. Learn more about power resistors here.