All Transistor Equivalent Book Review

| Original Transistor | Type / Package | Safe Equivalents (Direct Pin-to-Pin) | Notes | | :--- | :--- | :--- | :--- | | | NPN / TO-92 | PN2222A, 2N3904 (low power only), BC337, KSP2222A | The most common general-purpose NPN. 2N3904 has lower current (200mA vs 600mA). | | 2N2907 / PN2907 | PNP / TO-92 | 2N3906 (low power), BC327, KSP2907A | Complementary to 2N2222. | | 2N3904 | NPN / TO-92 | BC547, BC548, 2SC1815, 2N4401 | Low noise, general purpose. BC547 is European standard equivalent. | | 2N3906 | PNP / TO-92 | BC557, BC558, 2SA1015, 2N4403 | Complementary to 2N3904. | | BC107 / BC108 / BC109 | NPN / TO-18 (metal) | BC547 (plastic TO-92), 2N3904 | Pinout differs! BC107 has C-B-E; BC547 has C-B-E but check your PCB . | | BC557 / BC558 | PNP / TO-92 | 2N3906, 2N4403, BC327 (higher current) | Standard low-power audio PNP. | | BD139 | NPN / TO-126 | BD135, TIP29, 2SC2682 | Medium power. Common in audio drivers. | | BD140 | PNP / TO-126 | BD136, TIP30, 2SA1012 | Complementary to BD139. | | TIP31C | NPN / TO-220 | TIP41C, 2N3055 (different package), MJE3055T | 100V, 3A power transistor. | | TIP32C | PNP / TO-220 | TIP42C, MJE2955T | Complementary to TIP31. | | 2N3055 | NPN / TO-3 (metal) | MJ15003, MJ15024, 2N3773 | Classic 15A power transistor. Use TO-3 substitutes only. | | MJ2955 | PNP / TO-3 | MJ15004, MJ15025 | Complementary to 2N3055. |

When you find a "match" in a book or database, you must verify these four parameters to ensure it won't damage your circuit: all transistor equivalent book

: The current rating must be equal to or higher than the original. Check fTf sub cap T | Original Transistor | Type / Package |