求助：控制芯片在次级，电源怎么启动？
想做一个双管正激电路，想把PWM控制芯片放在次级。芯片供电次级的储能电感加一个绕组。初级开关管用MOSFET，驱动用变压器。想知道电源开机时怎么启动的？
全部回复(17)
正序查看
倒序查看
这个搞笑了@ymyangyong
对呀！双管正激如何实现自激启动？这个真有点难！
这个是电路图，我看不明白启动电路。
原文就这么一点文字描述。Start-up circuit
As already mentioned in the introduction section, the controller is located on the secondary side of the power
transformer, and for this reason, a start-up circuit has to be provided for a correct system activation.
The start-up circuit is based on a diac sending a train of controlled pulses to the low side drive section; the floating
drive section is energised by the second secondary gate driv
e transformer winding .
As soon as the L5991a wakes-up, it generates a pwm signal enabling the start-up circuit.
0
@grtang
这个是电路图，我看不明白启动电路。原文就这么一点文字描述。Start-upcircuitAsalreadymentionedintheintroductionsection,thecontrollerislocatedonthesecondarysideofthepowertransformer,andforthisreason,astart-upcircuithastobeprovidedforacorrectsystemactivation.Thestart-upcircuitisbasedonadiacsendingatrainofcontrolledpulsestothelowsidedrivesection;thefloatingdrivesectionisenergisedbythesecondsecondarygatedriv[图片] etransformerwinding.AssoonastheL5991awakes-up,itgeneratesapwmsignalenablingthestart-upcircuit.
启动电路
由于已经在引言部分提到，位于电源的二次侧控制器变压器，因为这个原因，启动电路必须提供正确的系统激活。
发送DIAC 低侧驱动部分 列车的控制脉冲启动电路是基于浮动
驱动部分由第二栅极驱动变压器绕组通电。一旦作为L5991a唤醒的，它会产生一个PWM信号，使启动电路。
0
