Before we proceed with what we were asked to do and how we will do it, I should first discuss the safety capacitors, what they are, and their purposes.
X1, X2, Y1, and Y2 capacitors are safety capacitors used in electrical and electronic equipment to suppress electromagnetic interference (EMI) and radio frequency interference (RFI) and to provide electrical isolation for safety purposes. These capacitors are classified based on their voltage ratings and the types of equipment they are designed to be used in. Here is a brief explanation of each type:
X1 capacitors are designed for use in applications where their failure could result in electric shock hazards. They are typically used in the input circuits of devices directly connected to the main power grid. X1 capacitors are rated for voltages up to 440 VAC and subjected to more stringent safety tests than X2 capacitors.
X2 capacitors are also safety capacitors used for EMI suppression and safety isolation. They are typically used in applications where failure of the capacitor would not result in electric shock hazards. X2 capacitors are rated for voltages up to 275 VAC and are commonly used in appliances and equipment that are connected to the main power grid.
Y1 capacitors are designed for use in applications where failure of the capacitor could result in a risk of fire. They are intended for use in circuits that are directly connected to the main power grid. Y1 capacitors are rated for voltages up to 500 VAC and subjected to more rigorous safety tests than Y2 capacitors.
Y2 capacitors are used in applications where failure would not result in a risk of fire. They are rated for voltages up to 300 VAC and are commonly used in equipment connected to the main power grid. However, if the capacitor fails, it does not pose a fire hazard.
In summary, X1 and Y1 capacitors are designed for applications where safety is critical, while X2 and Y2 capacitors are used in applications with less stringent safety requirements. X1 and Y1 capacitors are used in the EMI/transient filtering stages of power supplies.
The Challenge!
We were asked to conduct noise measurements on various X1 caps to find the quietest of all. For those of you who didn’t know, X-caps can be the source of electronic noise, so finding the less noisy ones can be a challenge, requiring a dead-silent hemi-anechoic instrument and state-of-the-art equipment. Since we already have these, the only thing missing was a special “device” that would allow us to check X-caps easily and safely. At the same time, it should be adjustable to allow us to bring the X-cap under test at the specified distance from our MIC. George, an engineer at the Cybenetics lab, is always up to the challenge of implementing any solution required according to the test scenario. You will find a photo of his creation below. Simplistic, but highly usable!
