# Tag Info

## New answers tagged npn

0

The important piece of missing information is that in the circuit, current through the resistor flows into the collector -- both currents are Ic, and they are the same. So, for a given base current, the blue line shows you how Ic changes with Vce, as determined by the transistor. The red line shows you how Ic changes with Vce, as determined by the resistor....

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The load line plot does a poor job of demonstrating the non-linear voltage error of a large swing output. But it does tell you the base current needed vs output voltage. A better plot would be error voltage vs output for a given load current V/R and current or voltage gain. But for high current and full swing, you can see the spacing between base steps ...

1

The transistor characteristics say what the transistor does. The load line says what the resistor does. The intersection of the transistor characteristic lines with the resistor load line says what the amplifier does.

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Bz1 is a self-oscillating warning buzzer, and the circuit around R1, T1 & Bz1 is an over-current warning. The current from the power supply drawn by the load you connect to it ends up returning through R1. When the current increases sufficiently to cause enough of a voltage-drop across R1, T1 begins to turn on which in turn causes Bz1 to buzz at you. ...

1

You are so very close to answering your question. You want to know how to calculate the collector current and aren't sure how to develop that value. But let's look at the schematic again: simulate this circuit – Schematic created using CircuitLab Note that I've now included some information that was included in the question that you may have missed ...

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Since you need to find the transistor's beta you should calculate what the collector and base current must be for Vi=Vo=(Vcc/2) to be true. In order for Vo to be Vcc/2 than Rc must have Vcc/2 volts dropped across it. From ohms law you should get the needed current for that to be true. Using the parameters given for Vbe you should be able to calculate the ...

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Figure 1. From the datasheet on the linked site. The diagram is telling us to power the sensor on 1 (+) and 3 (-) and connect the load between 1 and 4. simulate this circuit – Schematic created using CircuitLab Figure 2. The internals of the sensor. These sensors are far more complex that you seem to have imagined. The type you have chosen is a ...

1

NPN photo detectors usually leave the base open, or tied with a very large resistor to the emitter. Normally the light hitting the transistor excites the base-emitter, causing base current to flow. The collector draws more current, due to the transistors current gain. So then a resistor in the collector, biased positive (VCC) relative to the emitter allows ...

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