How do you calculate the resistance of a transistor?
Yes the simplest method to figure out the equivalent resistance is to measure the collector voltage Vc and the emitter voltage Ve and subtract: V=Vc-Ve, and then measure the current through the collector Ic. The approximate resistance (neglecting the base current) is: R=V/Ic.
How do I know which resistor to use for transistor?
To calculate the base resistor, subtract the B-E 0.7V from the driver voltage and divide by the base current: 4.5-0.7 = 3.8V / 400uA = ~9.5K ohms max. The difference in CE drop between a factor of ten and using the beta is neglible for relatively slow on/off circuits, and it lowers the driver current requirement.
What is the beta value of q2n2222?
In this experiment we measure the constant β ≡ Ic/Ib for a 2N2222 transistor. We show that β is in fact constant in the linear regime and equal to approximately 190. In addition, we show that the linear regime is realized for base currents of Ib < 50 μ A and that in this regime the voltage hierarchy is satisfied.
How do you calculate the voltage at the base of a transistor?
This can be done using the formula: Vcc = Vrc + Vrb + Vbe + (Ic + Ib)Rc + IbRb + Vbe, where “Vrc” is the voltage across the collector resistor; “Vrb” is the voltage across the base resistor (connected across the base) and the junction between the collector resistor and the transistor collector; and “Vbe” is the voltage …
What is the ideal resistance for a 2N3904 base resistor?
What is the ideal resistance for a 2N3904 base resistor value when using RTL logic? I have a ton of 2N3904 transistors and would like to use them for my RTL logic project. Based on what I could figure out on the web, and the parts I had, I’ve gotten logic gates to work quite well with the following values:
What should the base resistor value be for a transistor?
Your selection of 10kΩ is close enough. You can also scale the resistor values up, maintaining the ratio of base to collector current, but reducing the current overall. That reduces your power consumption, but also reduces the logic speed as the smaller currents are able to charge the parasitic capacitances less rapidly.
When is a transistor said to be saturated?
When the base current increases to the point where collector current can increase no more, the transistor is said to be saturated. The collector current can increase no more because it can’t permit any more current — the current is entirely limited by R1 in your diagram, and the voltage from emitter to collector is at a minimum.
How to calculate the current through a transistor?
There are several ways to calculate this but the easiest way for me is to calculate the currents and go from there. So the current through R4 when the transistor base is at 0.7V is 0.7V / 80kΩ = 8.75μA. Now we need to add some base current to this value. The LED current is affected by its ON voltage.