New answers tagged transistors
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Sizing an CMOS StrongArm Latch comparator on Virtuoso from scratch
If you know Id, Vgs, and Vds, and a Virtuoso device model, you have enough information to solve for an approximate shape ratio under a few assumptions (namely, no body effect, if applicable you've ...
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Transistor works with just base connected
The base-emitter junction is a PN junction which is broadly similar to (but obviously with important differences from) a diode's PN junction that also allow it to control the flow of charge carriers ...
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Transistor works with just base connected
simulate this circuit – Schematic created using CircuitLab
Figure 1.
(a) A transistor when tested with a diode tester appears to be a pair of PN (diode) junctions.
(b) In this case Q2 is being ...
- 171k
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Transistor works with just base connected
Yes, it's normal, current into base flows out from emitter, regardless of what connections, if any, you have on the collector.
The base current controls the collector current. Both base and collector ...
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How do I select and use a BJT in a simple LED circuit?
Transistors don't have minimum voltage requirements per se, the limiting factor is generally the base emitter voltage \$V_{BE}\$ which is around 0.6 V for a silicon transistor.
For saturation, you'll ...
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The condition of linear operation of the transistor Dipole in small signal mode
For a BJT, the voltage scale is the thermal voltage, about 26 mV at room temperature. The base voltage change must be substantially smaller than that to approach linearity.
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Diode and bipolar NPN transistors orientation not correct, says JLCPCB
I guess what causes the populated view to show up inverted, is that the pick and place file generated from KiCad ends up 180° rotated for polarized components. Therefore, they fix this to adjust this ...
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NPN Transistor Base Current Calculation from Beta, Vth, and Rth
I'll write up something for you -- a problem and a solution. I'll make it tricky, but real. In fact, I just posted up this schematic a day or two ago. So it is fresh in mind. It may look like it ...
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Inconsistent resistance measurement in H-bridge
My hypothesis is that your transistors are slightly mismatched. The beta (hfe) on transistors can range between 30 and 400, which affects the effective emitter resistance.
I've simulated the scenario:
...
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How to determine the collector current limiting resistors for the Darlington's pair of transistors?
They're not particularly critical. Most of the current consumption is in the output circuit.
You can use the same values except replace [220Ω + buzzer + LED] with [1.5kΩ + LED] for about 5mA through ...
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Dual N/P-Channel MOSFET Dies with Smoke
When Q1 turns off, the drive is limited by the 47K resistor. The charge time is about R2 x total gate capacitance, or 47K x 3nf = 141us, and during this slow transition the n and p transistors burn as ...
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Am I using these MOSFETs correctly?
One likely problem is that the \$V_{GS}\$ you're applying to those MOSFETs, which is 5 V, is much lower than what they're designed for. The datasheet for the FQP30N06 promises that if \$V_{GS} \le 2 \ ...
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Am I using these MOSFETs correctly?
FQP30N06 is not a logic level FET so you can never switch it fully on with the Arduinos 5 V. Furthermore, it's a N-channel and you connected it before the load not after leading to even less on-state ...
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Three stage amplifier with third transistor connected to emitter of second
The used expressions for the 2nd stage is wrong. The gain must be positive and below unity (emitter follower).
The product of the individual gains for the 3 stages - when correctly calculated - gives ...
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Three stage amplifier with third transistor connected to emitter of second
Your circuit does not function correctly.
Here is what happens ... Q1 is deeply saturated, so "no" voltage gain.
Here is the AC Analysis of the circuit ...
After some changes, this should ...
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Three stage amplifier with third transistor connected to emitter of second
My question is that for voltage gain, is it correct if I take voltage
gain of each transistor and then multiplying, to get gain of whole
circuit?
That would be incorrect because you have AC negative ...
- 443k
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How can I calculate the current induced in the copper coil that is wrapped around a single phase of an 11kV, 2616A distribution line?
Your coil will have some capacitance to the HV line. You can look up formulae for cylindrical capacitors to get some idea of how much based on its geometry and the dielectric constant of its ...
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How can I calculate the current induced in the copper coil that is wrapped around a single phase of an 11kV, 2616A distribution line?
How can the current and voltage induced in the copper coil be
calculated so that the right transistors are used? I would like to
determine the base current of the transistor connected to the copper
...
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How to control unrelated circuit with a transistor?
Normally, it would be fine to connect the ground wires in the circuit you show. You have two battery powered supplies, so nothing bad will happen if you connect the circuits together.
If you really ...
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How to control unrelated circuit with a transistor?
Use an opto-isolator.
simulate this circuit – Schematic created using CircuitLab
An opto-isolator uses an infra-red LED and a photo-transistor encapsulated in the one package. They provide ...
- 171k
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Astable Multivibrator Not Oscillating
The base connections aren't crossed. You need to swap one end of the white and blue wires.
As Antonio said, the base resistors should be much larger than the collector resistor. I would use 22k and ...
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SMD SOT-23-3 device identification - top marking E8LJ0
It's a Infineon IRLML6402 P-Channel MOSFET.
(Source: lcsc.com)
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Astable Multivibrator Not Oscillating
Base resistors should be at least 10/20 times collector resistors.
These collector resistors should not be too low -> 1 kOhm.
Then the base resistors should be something like 10 kOhm or 20 kOhm.
NB:...
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How to make an LED light when motor stops running?
Swapping the inputs to the op amp (or comparator) ringed in red will achieve what you want.
OR
Change the LED driving transistor to a PNP, emitter to +5, collector to ground via LED (with appropriate ...
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Why NPN Transistor AND Gate not working?
I believe this is what you're trying to achieve: falstad simulation
Edit: A Tinkercad simulation showing the same circuit can be found here.
The discussions in the comments are follow-ups on OP's ...
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Why NPN Transistor AND Gate not working?
You need three resistors. The first should replace your link from pin 13 to Bat+. This will limit the overall current to the LED when the gate is turned on. I'd suggest about 1K. Then you need a base ...
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Correct circuit design to light an LED
In the schematic you posted, Q1 is semi-backwards. Connect the source to GND, reverse the LED, and connect the LED anode to the 3.3 V source. Now the transistor will act as a saturated switch for ...
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Correct circuit design to light an LED
EDIT: Your fixed circuit will work perfectly. The only thing is 100 ohms will make LED current quite high, you may not want to burn up the LED or be so bright - depends on your LED though. The LEDs I ...
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How to make an LED light when motor stops running?
This is not an actual answer, but I have to do it this way to provide a schematic, so bear with me.
Your output stage may give you difficulty, especially if you are trying for output near zero, which ...
- 60.3k
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Transistor Driver - what is the purpose of Q2 on the included schematic?
I think a systematic exposition supported by experiments would be a good addition to the other questions. The idea can be revealed in the sequence below.
Building the circuit
Unloaded CE stage
Let's ...
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Help in recognizing a component
The manufacturer is Microne and the closest part I could find is ME6208A30M3G which is a 3V LDO. As far as I can tell, Microne doesn't explain their markings anywhere, so it's impossible to say for ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
Compare the performance with and without Q2 (100kHz with 0.6Ω resistive load):
Without Q2 (specifically with Q2 connected as a diode) there is only the 1k resistor to charge the gate capacitance. So ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
What is the purpose of Q2 on the included
schematic?
Just consider the circuit without the diode (just for convenience): -
Q2 can deliver significant power a load (when the input voltage is zero). ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
Q2 is not simply a B-E diode, it is an emitter follower.
Without Q2, R1 pulls up with about 10mA, driving the load rather modestly. This is okay for small loads, like logic-level inputs, or even ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
The answer to the question you cite almost tells you what you want to know.
When Vi is high Q1 is driven into saturation and Vo is dragged to ground. Q2 is off as its base is -0.7V negative WRT its ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
Without Q2 and depending on Vi, the output is driven low by the low impedance transistor Q1 and driven high by the high impedance resistor R1. This is an asymmetrical output impedance.
Q2 is there to ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
Q2 makes it easier to switch off the output. When Vi is high, Q1 is active and steals the base current from Q2. This base current is much smaller than the output current; without Q2, all the output ...
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Help me identify this unknown SMD transistor
Personnaly i read "CCEQ" on the marking (not sure).
MCP3421A2T-E/CH has a marking type "CCNN" with NN date/lot code in SOT-23-6 package. It is an ADC with I2C interface, is this ...
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IR emitter circuit not working
There's many reasons they don't work or work poorly.
You are transmitting out only the baseband of the IR signal, which looks like NEC protocol. More specifically, it looks like Extended NEC protocol ...
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UJT Negative Resistance and Ohm's Law
Ohms law is broken for any non-linear device as the conductivity is not proportional to the voltage and current.
Transistors,diodes and memristors do not follow ohms law
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Why does my flyback transformer simply refuse to work?
You may want to take a look at this circuit. That's a company that makes and sells power supply kits for Kirlian photography.
That circuit uses an LM555 as an oscillator. It then drives the ...
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Problem with push pull output
At that point you may as well put the whole op-amp together :)
The circuit below has +/-1V (2Vpp) input and +/-7V (14Vpp) output. Increase C1 should there be any instability with your particular ...
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Problem with push pull output
Try the complementary Darlington configuration, aka "Sziklai pair" for the output stage, rather than the Darlingtion as shown in the OP. Refer schematic below, just connect the bases of Q3 &...
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Problem with push pull output
Your driver and output transistors have no DC bias.
Since your input signal is a squarewave from the oscillator then you do not need the coupling capacitors.
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Is there any way to know how real discrete components are being connected to each other using logical gates?
The question mentions VHDL and gate level primitives. However, VHDL doesn't provide support for gate level primitives.
Whereas the Verilog language does support gate level primitives. Gate Level ...
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Is there any way to know how real discrete components are being connected to each other using logical gates?
When you design in an HDL, you are not actually designing circuits. You are designing logic. Another program (typically) then takes this logic and performs the circuit synthesis based on your target ...
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Is there any way to know how real discrete components are being connected to each other using logical gates?
passive components are being connected to each other using logical
gates?
It depends on the process (TTL or a mosfet based design) in an IC. If one is building the gate on the bench then descrete IC'...
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Is there any way to know how real discrete components are being connected to each other using logical gates?
VHDL is a hardware language that is oriented toward creating logic. It knows about logical functions and connections between them (wires), and not much else. It isn’t inherently aware of transistor-...
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Can I convert 12 V DC to 24 V DC using a 2N2222A?
S7-1200 has IEC Type 1 sink inputs so you need to provide current of nominal 4 mA 24 V at the input (minimum 15 V).
One way to do that is with two transistors:
simulate this circuit – ...
- 384k
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Can I convert 12 V DC to 24 V DC using a 2N2222A?
If you can accept inverted logic into your PLC, this would do it:
simulate this circuit – Schematic created using CircuitLab
If you can't have inverted logic, use two:
simulate this circuit
...
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