DC input power is prevented joining conversely and antisurge typical circuit

The utility model provides a DC input power is prevented joining conversely and antisurge typical circuit, including resistance R7, resistance R8, resistance R11, resistance R12, resistance R13, zener diode ZD3, zener diode ZD7, electric capacity C17, electric capacity C21, electric capacity C36, triode Q3, MOS pipe Q8 and MOS pipe Q12, when the input is joined conversely, DC the end can't constitute the return circuit through MOS pipe Q12 when the positive voltage and flow back to DC+ and hold, MOS pipe Q12 does not have driving voltage and does not switch on, reverse voltage is all with manage Q12 DS both ends at MOS, no -voltage on the level circuit of back, thereby back level circuit has been protected. 种DC输入电源防反接与抗浪涌典型电路,包括电阻R7、电阻R8、电阻R11、电阻R12、电阻R13、稳压二极管ZD3、稳压二极管ZD7、电容C17、电容C21、电容C36、三极管Q3、MOS管Q8和MOS管Q12,输入反接时，DC-端为正电压时通过MOS管Q12无法构成回路流回DC+端，MOS管Q12无驱动电压不导通，反向电压全部加在MOS管Q12 DS两端，后级电路上无电压，从而保护了后级电路。