Contents
How do you find the base value of a resistor?
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.
What causes a resistor to burn up?
Burning of Resistor When a resistor has been overloaded with voltage exceeding its power rating, the resistor will become very hot to touch, darken considerably and possibly even melt or catch on fire.
Is a transistor a resistor?
A transistor is like a resistor, except that the resistor can be controlled by a second input called base input; It should also be noted that the gate input of the transistors is the transmitter and the output is the collector (its backward reason).
How does the BJT transistor work as a switch?
BJT transistor as a switch When a voltage is applied to the base of the transistor the bjt acts as a closed switch: the current can flow and the LED is turned on. When the voltage is removed the BTJ acts as an open switch, and no current can flow: the led is turned off. If you’ve missed the previous post, we recommend you to check it.
What does a base resistor do in a bipolar junction transistor?
Consider a base resistor that controls the amount of current entering the base junction of a bipolar junction transistor (BJT) to cause it to conduct in the saturation region.
How is the base of a transistor connected to the ground?
Because when the open collector is ‘high’ then the base of the transistor is at 12 V and it appears the 1 kohm resistor didn’t affect anything, and then when the open collector goes ‘low’ then the base is connected to ground through the output of the SN7407. So basically, what would the difference be if there was no 1 kilo-ohm resistor at all?
Where can I find the HFE value for a BJT transistor?
The hfe or gain value depends on the transistor and can be obtained from its datasheet. In this case, hfe = 40. Here’s the final circuit to meet our design specifications: Here are covered another kind of circuits using bjt transistors that you can find in [effect pedal circuits]: the common collector buffer and the switch.