C1815 VS BC547 – Differences Explained

In this post, we are going to discuss C1815 VS BC547 transistor. We will compare their pinout, ratings, and characteristics. Moreover, we will also discuss about their interchangeability and different situations in which we can and cannot use them in place of each other.

C1815 VS BC547 Pin Difference

As shown in the pin comparison chart above we can see that the pin configurations of both transistors are different. The C1815 transistor’s first pin is “Emitter” second is “Collector” and third is “Base”.  While the BC547 transistor’s first pin is “Collector” second is “Base” and third is “Emitter.

Ratings & Characteristics Comparison:

Can We Use C1815 Instead of BC547

By looking at the above ratings and characteristics chart we can see that C1815 has a higher collector-emitter voltage and also higher collector current due to which you can easily replace BC547 with C1815 in any circuit where it is used as a switch. Moreover, you can also replace C1815 with BC547 in other circuits easily such as an amplifier or preamplifier and the output will have not much difference. But if you want to replace it in an RF circuit then the frequency of the circuit must be around 80MHz. If the frequency is higher then you have to find some other alternative that has a higher transition frequency.

Can We Use BC547 Instead of C1815

You can use BC547 in place of C1815 in some conditions and in some conditions you cannot. You can easily replace BC547 with C1815 in amplifier, preamplifier, oscillator, and RF circuits but you cannot replace it in all switching circuits because C1815 has a higher collector-emitter voltage and also higher collector current. If you want to replace it in a switch circuit, it should be noted that the collector current of C1815 is higher than that of BC547 so first of all you have to find out what load C1815 is driving and how much current that load is using. This can easily be checked with a digital multimeter by selecting the ampere option and connecting its two leads between the load and the transistor. You will also find many tutorials on Youtube on how to check amperes. The other way to check the current of the connected load is by checking the spec sheet of that load. For example it that load is a relay then you have to find out how much current that relay requires. If that load requires more than 80mA then you have to find out some other alternative that has of 150mA collector current.

Conclusion

So now it is clear that we can interchange them when they are used as an amplifier but when it comes to using them as a switch there are some conditions in which we cannot use them interchangeably. The S8050 collector to emitter voltage is 25V so it cannot be used in the place of BC547 when the load requires more than 25V and the other condition is when it is used in an RF circuit above 100MHz. And when you want to replace BC547 in place of S8050 it cannot be replaced only in one condition when the load requires higher current than 80mA. Rather than that you can use BC547 in place of S8050 in all conditions.