Q&A(FAQ) What happens if high/low input frequency is applied?
Commercial AC input frequencies are typically 50 Hz or 60 Hz. Although frequency variation has little effect on electrical characteristics such as output voltage in switching power supplies, the specified operating range is 47 to 63 Hz.
For models with safety agency approvals, operation within the designated frequency range is required to maintain compliance with the applicable safety standards.
1. High input frequency
Among our power supplies, some models can operate with an input frequency of 47 to 440 Hz, while others are limited to a range of 47 to 63 Hz.
Operating the product at a frequency higher than the specified rating increases losses in the input filter circuit as well as in the rectifier and smoothing stages. This results in lower efficiency and greater temperature rise, and therefore such operation should be avoided.
In addition, audible noise may increase, and in models equipped with PFC circuits, a reduction in power factor may also occur.
2. Low input frequency
When the input frequency falls below the specified range, the charging interval of the primary-side smoothing capacitor becomes longer than normal, preventing sufficient charge from accumulating. As a result, the output ripple voltage may increase and the output voltage may decrease.