1. ### Are ISFETS available for cheap or am I out of luck

I was looking into measuring the ph levels of a lake nearby where I live. I wanted to tie the experiment to my electronics coursework so I did some reasearch and found the wonder electronic that is the ISFET. Unfortunately, I cannot find anywhere to buy an ISFET transistor; I can easily find...
2. ### Transformer Coupled Class A amplifier Single supply

How can Vce vary from 0 to 2Vcc? In class, I learned that it was due to Lenz Law working in the transformer and a voltage of Vcc being induced to reverse the change in Ic. However, I cannot picture this. Can someone please explain with a diagram of how this comes about in the transformer windings.
3. ### How to select a transistor?

Say you want to choose a npn transistor which works for 1000V and 4mA (Peak inductance current is around 1A) in the collector side while emitter is grounded. Which parameters should I look into to select a suitable transistor ? for the voltage should I be looking into Vbe ? or is Vce enough ...
4. ### How to calculate Carrier Concentration vs. Depth from a CV measurement?

I'm trying to obtain the free carrier concentration vs depth profile from the CV (capacitance-voltage) measurements of a normally-on HEMT with the expressions used for a Schottky barrier, but I´'m confused about how to extract the values for depth. I found in textbooks and articles that the...

18. M

### Question about circuits with transistors (current, voltage)

Homework Statement 1. In Figure A-1 of Experiment 18, assume that Vdc = 8Volts, R1 = 1kOhms, R3 = 7kOhms and there is no R2 resistor. Determine the current in R1 when the transistor is fully on and carrying current. Express your answer in mA. 2. In the circuit of Figure A-1, Experiment 18...
19. ### Transistors and Beta

Homework Statement I have this circuit Where I have to find R given that I=2mA, and Beta =200 Homework Equations Ic=Beta Ib Ie = Ic+Ib The Attempt at a Solution I would have thought that the voltage Vb would be -9.3V, since we have Vbe = 0.7 and at the bottom we are given -10V. Then I would...
20. ### Increase the maximum voltage rating of semiconducter

Hello, I was wondering if there is any way of increasing a transistor or thyristor maximum voltage ratting in DC? Thanks. Edit: Just to be more precise, I am referring to the off state. I know you can the on state via a resistor.
21. ### PNP Transistor voltage calculation

For the B) part, I don't get why is it that for calculating voltage between collector an the emitter (Vce) I take into account diode on base (0.7V), whereas for part A) it's ignored? Why is Vce in part A and part B are calculated differently? Why is it that in part A voltage of 0.7V isn't taken...
22. ### BJT and MOSFET complete analysis

Homework Statement I have been given the world's longest transistor problem as an assignment :wink: Here is the circuit: I am asked to find: a) V1, V2 and V3 using DC analysis b) AC equivalent circuit c) AC tension gain: Ava=Vx/Vsig d) AC tension gain: Avb=Vo/Vx e) Total AC tension gain...
23. ### Calculating the amplification of a transistor

Homework Statement In the circuit shown below, I have to find the amplification for when the commutator which connects to the 4 kΩ resistance is open, respectively closed. We know the Beta factor to be 200, and the current through the base is negligible. The transistor is made of silicone...
24. ### Electrical DIY wireless power transfer device concept

i am planning to do a small diy wireless power transfer device. The circuit of the transmitter is receiver has just the coil and load arrangement. my query is, (please correct me if am wrong) -->to induce a voltage in the secondary coil, there must be a varying magnetic field right? -->but...
25. ### BJT transistor analysis: common emitter confusion

Recently I started studying semiconductors and analogue electronics. First I studied the diode and its I-V characteristics and analysis in DC circuits, as well as in AC circuits. Now I started with BJT transistors. I was explained that transistors act as electronic switches. My problem is not...
26. ### I'm looking for this transistor

Hi, I need this transistor, but I have no more references than this number. https://scontent-yyz1-1.xx.fbcdn.net/v/t1.0-9/13886417_1422976724395700_8867555117386392787_n.jpg?oh=cb0057241b92e5fa390e134efba217c0&oe=581E9C28
27. ### NPN BJT transistor: base voltage / emitter current

I don't know how to calculate the voltages at the bases of every transistor shown in the lower row of that picture (~3V (2.9..V), ~2V, ~1.8V). Any help would be appreciated! - I'm currently trying to figure that out... The other thing I don't really understand: Why do the transistors in the...
28. ### Capacitive touchscreen control using a transistor

Hello, I'm posting the first time on this forum. I want to create a robot controlled by an Arduino which is able to make a touch signal without using a mechanic arm or finger ( here is a robot with the same goal but using an arm video). I want to take the electrical approach. A modern...
29. ### Why is my transistor overheating?

Okay so I am having this problem with a transistor overheating in a motor control circuit and I am not exactly sure why it is overheating. There is a PWM signal being used to power the transistor from an MSP430 microcontroller. I am using a standard 1N004 kickback diode for the motor and an...
30. ### Classical Understanding transistors

I am having troubles understanding the working of a bipolar junction transistor(and also its uses as switch, amplifier, oscillator etc.). Can anyone recommend any good book or video explaining it?