Switch power adapter is what kind of switch power adapter output overload protection are there?
In order to effectively protect the safety of the adapter performance, in order to ensure that the adapter is in use process operation requirements can adapt to different environments and be able to provide users with a steady current voltage into work, engineers often provide the appropriate output overload protection for the adapter.
Switch power adapter as a kind of commonly used power supply power transformation equipment, such as notebook computers, mobile phones, digital cameras are configured in electronic products.
In order to guarantee safety performance for the adapter, power adapter will normally adopt some output overload protection technology, within the protection power supply system at the same time, guarantee the stability of output and security.
This article will introduce four kinds of the more widely used output overload protection technology, in order to help engineers to better complete the adapter design work of new products.
1, the flyback power limit protection against ultra power protection at present in domestic adapter is widely applied in the process of research and development and the manufacturer production, this protection technology is one of the forms of the speed on extension, in the form of a circuit to monitor the voltage, current and deputy while reducing power in the output voltage fall.
Through this method, when the load resistance decreased reduce output current, prevent vice edge components by a strong stress damage, its disadvantage is used in the nonlinear load locking phenomenon happens.
Above is based on two application more switch power adapter output overload protection technique is introduced, hoping to help engineers to complete the design work.
2, constant power, constant input power limit protection limit protection is relatively common in the international one of switch power adapter output protection technology, the protection principle of this method is that by limiting the maximum transmission power to protect the original circuit.
But in flyback, this technique can hardly protect the vice and output components.
When the load resistance decrease, load exceeds its limit value, the output voltage began to decline.
It is because the product of input and output voltage and current, output voltage when begin to decline, the output current will rise.
3, super delay shut off power protection super delay shut off power protection is in the process of research and development of the power adapter, must have a output overload protection technology.
In delay tripping type system, a short transient current requirement is allowed, only when the current stress for a long time more than what is the power will be off.
Short transient current offer will not damage the power supply reliability, and will not bring great influence to the cost of the power supply.
Only the requirements of current for a long time will affect cost and volume of the circuit.
The power output of transient current, its performance will be reduced to a certain extent, may exceed the prescribed voltage error and ripple values.
4, each pulse of the super power or current limits for each pulse super power or current limit is very effective in the practical application of the output of the overload protection method, in additional margin often use this technique in the current protection.
In previous switch equipment, input current is to real-time monitoring.
If the current exceeds the specified limit current value, conduction pulse will be terminated.
In not renew a flyback, its biggest current determines the power of the circuit, this type of protection circuit becomes a real power limitation protection circuit.
Above is for everybody introduced the switch power adapter output overload protection methods are: the flyback super power limit protection, constant power limit protection, super delay shut off power protection, each pulse of the super power or over current limit and so on four big method.
In this respect knowledge must further again, hope to be able to help engineers to complete the design work.