1. All parameters NOT specially mentioned are measured at 230VAC input, rated load and 25℃ of ambient temperature.
2. Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair-wire terminated with a 0. 1uf & 47uf parallel capacitor.
3. Tolerance : includes set up tolerance, line regulation and load regulation.
4. Line regulation is measured from low line to high line at rated load.
平安彩票The topology of switching power supply refers to the form of switching power supply circuit. Generally, according to the output ground wire and the input ground wire has no electrical isolation, divided into isolated and non-isolated converters. Non-isolation means that the input end is connected with the output end, without isolation measures, common DC/DC converters are mostly of this type. The so-called isolation refers to that the input end and output end are not directly connected on the circuit. The energy transfer is carried out through electromagnetic transformation with the use of isolation transformer. The input end and output end are completely electrically isolated. Generally speaking, in order to protect the personal safety of the user, the switch power supply using the main power supply (mains) or input voltage higher than the safety voltage (currently recognized as 36 volts) must be isolated.
All isolated topologies contain a transformer that can be adjusted for higher or lower or negative potential output voltages. In some topologies, multiple windings can be wound around a transformer to output multiple voltage values. Some converters also use transformers as energy storage devices, while others still require independent inductors. Their power conversion mode is "dc - ac - dc" conversion.
In quasi-resonant zero-current/zero-voltage switch (ZCS/ZVS), electric energy is divided into packet output of a certain size. The switching turns on and off at the point of zero current and zero voltage, forming a loss-free switch. quasi-resonant switch, also known as "valley switch", can reduce electromagnetic interference from the following two aspects:
平安彩票When the voltage value drops to the minimum (at the trough), the bipolar switching device switches to minimize the electromagnetic interference caused by the hard switching effect.
When a valley value is detected, the switch is activated rather than triggered by a fixed cycle/frequency switch device, introducing a natural frequency jitter that separates the rf emission spectrum to reduce the overall electromagnetic radiation.
Control mode refers to the method of stabilizing voltage output. The sampling quantity can be divided into current mode and voltage mode.
Voltage mode: control mode with negative feedback by sampling the output voltage.
Current mode: negative feedback control mode for sampling input current and output voltage.
Double voltage mode: negative feedback control mode of sampling output voltage and input voltage.
平安彩票From the transfer function, can be divided into PID and Bang-Bang control
平安彩票PID control: first or second order PID control system constructed by sawtooth generator and compensation network.
Bang-Bang control: hysteresis control system constructed by comparator only. Also known as the hysteresis mode.