Melfior_Ra
New Member
Hi everyone.
i am trying to figure out how it is working this short circuit protection.
If i want to limit the current up to 4 A then Rsc should be 0.7/4 = 0.175 ohm. At this point Q2 starts conducting, the voltage at Q1 emitter is 11.3V, the voltage at Q2 collector is 10.6V which leads to voltage drop across r1 of 1.4V .The current through R1 is 1.4/R1 wich is arround 460 mA . To this current will add Q2 collector current and Q1 base current. All of this is taking by the LM 7805. How can i find this current (Ir1, IcQ2, IbQ1) ?
Please help me . Is this a good solution for current limiter?
i am trying to figure out how it is working this short circuit protection.
If i want to limit the current up to 4 A then Rsc should be 0.7/4 = 0.175 ohm. At this point Q2 starts conducting, the voltage at Q1 emitter is 11.3V, the voltage at Q2 collector is 10.6V which leads to voltage drop across r1 of 1.4V .The current through R1 is 1.4/R1 wich is arround 460 mA . To this current will add Q2 collector current and Q1 base current. All of this is taking by the LM 7805. How can i find this current (Ir1, IcQ2, IbQ1) ?
Please help me . Is this a good solution for current limiter?