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Rohat Kılıç
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but I cannot still find the currents properly

All currents can be found by solving a system of 4 equations.

We already know that \$\mathrm{|V_{CE}|=0.2V}\$ and \$I_E=I_B+I_C\$ for both NPN and PNP transistors.

Here are all the equations:

Equation-1 (from Vcc to PNP's emitter to base to ground):

$$ \mathrm{ 10V=10k \ I_{E1}+0.7V+10k \ I_{B1} \\ \therefore 9.3V=10k\ (2\ I_{B1}+I_{C1}) \ \ \ \ ... (1) } $$

Equation-2 (From Vcc to PNP's emitter to collector to ground):

$$ \mathrm{ 10V=10k\ I_{E1}+V_{EC-pnp}+10k\ (I_{C1}-I_{B2}) \\ \therefore 9.8V=10k\ (2\ I_{C1}+I_{B1}-I_{B2}) } $$

Equation-3 (From PNP's collector to ground and from NPN's base to emitter to ground): $$ \mathrm{ 10k\ (I_{C1}-I_{B2}) = V_{BE-npn} + 10k\ I_{E2} \\ \therefore 10k\ (I_{C1}+I_{C2}-2I_{B2})=0.7V } $$

Equation-4 (From Vcc to NPN's collector to emitter to ground): $$ \mathrm{ 10V=30k\ I_{C2}+V_{CE-npn}+10k\ I_{E2} \\ \therefore 9.8V=10k\ (4\ I_{C2}+I_{B2}) } $$

There are 4 unknowns and 4 equations. If you solve this 4-eq system via matrices (preferably) or replacements (too difficult), you'll find that;find;

\$\mathrm{I_{B1}\approx0.285mA}\$

\$\mathrm{I_{B2}\approx0.026mA}\$

\$\mathrm{I_{C1}\approx0.360mA}\$

\$\mathrm{I_{C2}\approx0.238mA}\$

Don't forget to crosscheck.

but I cannot still find the currents properly

All currents can be found by solving a system of 4 equations.

We already know that \$\mathrm{|V_{CE}|=0.2V}\$ and \$I_E=I_B+I_C\$ for both NPN and PNP transistors.

Here are all the equations:

Equation-1 (from Vcc to PNP's emitter to base to ground):

$$ \mathrm{ 10V=10k \ I_{E1}+0.7V+10k \ I_{B1} \\ \therefore 9.3V=10k\ (2\ I_{B1}+I_{C1}) \ \ \ \ ... (1) } $$

Equation-2 (From Vcc to PNP's emitter to collector to ground):

$$ \mathrm{ 10V=10k\ I_{E1}+V_{EC-pnp}+10k\ (I_{C1}-I_{B2}) \\ \therefore 9.8V=10k\ (2\ I_{C1}+I_{B1}-I_{B2}) } $$

Equation-3 (From PNP's collector to ground and from NPN's base to emitter to ground): $$ \mathrm{ 10k\ (I_{C1}-I_{B2}) = V_{BE-npn} + 10k\ I_{E2} \\ \therefore 10k\ (I_{C1}+I_{C2}-2I_{B2})=0.7V } $$

Equation-4 (From Vcc to NPN's collector to emitter to ground): $$ \mathrm{ 10V=30k\ I_{C2}+V_{CE-npn}+10k\ I_{E2} \\ \therefore 9.8V=10k\ (4\ I_{C2}+I_{B2}) } $$

There are 4 unknowns and 4 equations. If you solve this 4-eq system via matrices (preferably) or replacements (too difficult), you'll find that;

\$\mathrm{I_{B1}\approx0.285mA}\$

\$\mathrm{I_{B2}\approx0.026mA}\$

\$\mathrm{I_{C1}\approx0.360mA}\$

\$\mathrm{I_{C2}\approx0.238mA}\$

but I cannot still find the currents properly

All currents can be found by solving a system of 4 equations.

We already know that \$\mathrm{|V_{CE}|=0.2V}\$ and \$I_E=I_B+I_C\$ for both NPN and PNP transistors.

Here are all the equations:

Equation-1 (from Vcc to PNP's emitter to base to ground):

$$ \mathrm{ 10V=10k \ I_{E1}+0.7V+10k \ I_{B1} \\ \therefore 9.3V=10k\ (2\ I_{B1}+I_{C1}) \ \ \ \ ... (1) } $$

Equation-2 (From Vcc to PNP's emitter to collector to ground):

$$ \mathrm{ 10V=10k\ I_{E1}+V_{EC-pnp}+10k\ (I_{C1}-I_{B2}) \\ \therefore 9.8V=10k\ (2\ I_{C1}+I_{B1}-I_{B2}) } $$

Equation-3 (From PNP's collector to ground and from NPN's base to emitter to ground): $$ \mathrm{ 10k\ (I_{C1}-I_{B2}) = V_{BE-npn} + 10k\ I_{E2} \\ \therefore 10k\ (I_{C1}+I_{C2}-2I_{B2})=0.7V } $$

Equation-4 (From Vcc to NPN's collector to emitter to ground): $$ \mathrm{ 10V=30k\ I_{C2}+V_{CE-npn}+10k\ I_{E2} \\ \therefore 9.8V=10k\ (4\ I_{C2}+I_{B2}) } $$

There are 4 unknowns and 4 equations. If you solve this 4-eq system via matrices (preferably) or replacements (too difficult), you'll find;

\$\mathrm{I_{B1}\approx0.285mA}\$

\$\mathrm{I_{B2}\approx0.026mA}\$

\$\mathrm{I_{C1}\approx0.360mA}\$

\$\mathrm{I_{C2}\approx0.238mA}\$

Don't forget to crosscheck.

Source Link
Rohat Kılıç
  • 38.5k
  • 3
  • 32
  • 92

but I cannot still find the currents properly

All currents can be found by solving a system of 4 equations.

We already know that \$\mathrm{|V_{CE}|=0.2V}\$ and \$I_E=I_B+I_C\$ for both NPN and PNP transistors.

Here are all the equations:

Equation-1 (from Vcc to PNP's emitter to base to ground):

$$ \mathrm{ 10V=10k \ I_{E1}+0.7V+10k \ I_{B1} \\ \therefore 9.3V=10k\ (2\ I_{B1}+I_{C1}) \ \ \ \ ... (1) } $$

Equation-2 (From Vcc to PNP's emitter to collector to ground):

$$ \mathrm{ 10V=10k\ I_{E1}+V_{EC-pnp}+10k\ (I_{C1}-I_{B2}) \\ \therefore 9.8V=10k\ (2\ I_{C1}+I_{B1}-I_{B2}) } $$

Equation-3 (From PNP's collector to ground and from NPN's base to emitter to ground): $$ \mathrm{ 10k\ (I_{C1}-I_{B2}) = V_{BE-npn} + 10k\ I_{E2} \\ \therefore 10k\ (I_{C1}+I_{C2}-2I_{B2})=0.7V } $$

Equation-4 (From Vcc to NPN's collector to emitter to ground): $$ \mathrm{ 10V=30k\ I_{C2}+V_{CE-npn}+10k\ I_{E2} \\ \therefore 9.8V=10k\ (4\ I_{C2}+I_{B2}) } $$

There are 4 unknowns and 4 equations. If you solve this 4-eq system via matrices (preferably) or replacements (too difficult), you'll find that;

\$\mathrm{I_{B1}\approx0.285mA}\$

\$\mathrm{I_{B2}\approx0.026mA}\$

\$\mathrm{I_{C1}\approx0.360mA}\$

\$\mathrm{I_{C2}\approx0.238mA}\$