Electronic Design (1): the anti-reverse power diode circuit

串联防反接原理

• V1 access timing, D1 is turned on, the voltage drop is assumed as D1 $V_F$, The voltage applied to the load is $V1-V_F$This circuit will disadvantage is loss, the power loss is $P=I*V_F$, The output voltage required by the need to consider the voltage drop of D1 $V_F$Size, a large current circuit output current value D1 to be considered, it is generally used in high pressure applications;
• When the reverse power V1, using the reverse blocking diode characteristics impede current flow, can not form a loop with the load R1, protect the load.
  
  二极管串联防电源反接电路

并联防反接原理

• Then V2 timing, D2 in the reverse off circuit to work;
• When reverse V2, D2 is forward at this time, the reverse voltage clamp $V_F$(The diode voltage drop), $V_F$It requires less than the maximum reverse voltage of the load; the other hand, when the PTC is detected loop current is too large, open, rear end load protection. This circuit is one more disadvantage fuse, BOM cost increase, if a plurality of loads connected behind V2, by using the circuit need extra attention, fuse select recoverable fuse.

二极管并联防电源反接电路