SCR Power Controllers – Accurately Mounting and Aligning Parts
Proper mounting is even more important for a Hockey Puk SCR, then it is for SCR Power Controllers. The hockey puck SCR must be exactly centered on the mounting surface. If the centering pin is not properly aligned, then the pole face will not properly seal on the mounting surface and the silicon wafer inside the hockey puk, will not seal properly either. When everything is properly aligned on the other hand, then all services should be touching perfectly, the pole surfaces should be parallel to each other and the electricity and heat should travel smoothly from one surface to the next. This means that your hockey puk SCR will run cooler and last longer.
This is where the SCR Power Controllers come in. Hockey puk SCR’s require a specialized clamp, known as a heatsink clamp. This clamps the SCR together with its mounting surface and it is selected, based upon the desired mounting pressure, the diameter of this SCR and the distance from one mounting surface to another. The clamping force information is available from the SCR manufacturers and the higher the power rating of the SCR is, the more mounting force is needed.
Different types of SCR clamps are available from different manufacturers. There are those with spring gauges and those with pre-calibration indicators, which are the most common type of SCR heatsink clamp. They use stacks of Belleville washers to predetermine the clamping force, which is established when the pre-calibration indicator is loose and therefore, they eliminate the need for special torque wrenches or tools. Spring type clamps on the other hand, either require special tooling, or are temperamental. This is why pre-calibrated clamps are the most popular.
Effective Assembly of Different Shapes and Sizes
There are many different shapes and sizes of SCR Power Controllers, because there are many different shapes and sizes of hockey puk SCR’s. It is important that they be installed properly by following the proper steps and procedures. First, you assemble all the parts loosely and make sure that heatsink thermal compound was used on the SCR pole faces. Next, you finger-tighten the two clamp bolts. Then you verify that the top and bottom mounting surfaces are parallel. Make sure that the SCR is centered in the assembly and that the locating pin is in the hole on the mounting surface. Then use a wrench, to tighten each of the bolts one quarter turn at a time, until the pre-calibration indicator is loose to the touch.
Proper Application of Thermal Compound
For both SCR Power Controllers and hockey puk SCR’s, heatsink thermal compound must be used between the surfaces to ensure the proper flow of heat and electrical conductivity. For the SCR Power Controller, the heatsink thermal compound can simply be a good thermal conductor. However, for the hockey puk SCR, the heatsink thermal compound must also be a good electrical conductor. For both SCR Power Controllers and hockey puk SCR’s, proper installation is extremely important to avoid premature failure. However, installation of hockey puk SCR’s requires the most care and skill and failure to connect the SCR properly can lead to overheating and premature failure, so it is extremely important to choose the right SCR Power Controllers and to install them properly.
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