At Bearing-Belt & Chain, we carry a wide array of power transmission products for our customers to ensure they have everything they need to operate effectively and efficiently. SCR drives are just one of the many power transmission products that we carry. SCR stands for ‘silicon-controlled rectifier.’ Machine Design shares a helpful description of the origins of SCR drives and how they are used, “With its introduction in the 1950s as a variable voltage-controlling device in acto-dc conversion applications, SCRs are the oldest controllable power semiconductor…To easily understand how an SCR works, consider its function in a typical dc drive, which was the first general industrial application. In these drives, SCRs control dc motor speed and torque by converting ac line voltage to adjustable dc voltage. To do this, the controller determines when in the ac half cycle to turn the SCR on so it conducts to the end of that half cycle. The earlier in the half cycle the SCR turns on, the higher the average output voltage is to the motor. To turn the SCR on, the controller applies a current to the SCR gate…SCRs are capable of handling large amounts of current — 5,000 A to 10,000 A. But large devices are needed to handle high currents; and the larger the device, the slower its switching characteristics…For dc drives, SCRs are the least expensive power semiconductor for applications below a power range of 200 to 500 hp.”
SCR drives area low-cost piece that helps control the amount of current flow to DC motors. SCR drives function much like a gate that allows voltage to vary easily but efficiently and safely. There are different types of SCR drives and it is important to carefully examine the manufacturer’s data sheet when investing in an SCR drive to ensure it is appropriate for your specific application. Important factors to consider include things like gate leads and triggers, blocking voltages, and critical rate of rise. Being aware of what your SCR drive can and cannot do is important to protect your investment and not break your SCR drive altogether. If you are looking for a cost-effective way to control the current flow to your DC motor in a power transmission application, an SCR drive may be the right fit for you.
