Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options answers only not deleted user 3288

BJT stands for Bipolar Junction Transistor. It is a three-terminal electronic device constructed of doped semiconductor material and may be used in amplifying or switching applications.

2 votes

BJT push-pull modification

Mainly an aside: Remove D3 and D4 and see what happens. These are output stage antisaturation diodes that stop the output transistors being driven into saturation so that they recover more rapidly on …
  • 145k
2 votes

How to improve symmetry of +/-1 gain circuit?

Massively overdriving a BJT so that it has a forced beta of say 0.1 or even less allows a very low saturation voltage. Long ago I had a BJT switching a resistor and the junction needed to be ~ 0. …
  • 145k
0 votes

Alternating between two LEDS using BJTs

Just for fun :-). I'll add comment to this in due course if necessary. But, for now: Does it work? How does it work? R2 is optional. What does it do and what happens if it is omitted? simula …
  • 145k
1 vote
Accepted

What exactly is meant by beta dependence in this fixed bias BJT scheme?

Rearranging your formulae and using your assumptions: Rb = (Vcc-Ve) x (Re/Ve) x Beta. -> Rb is proportional to Beta. and/or, re-rearranging Ve = (Vcc x Re)/ ( Beta x Rb + Re) <- Ve is B …
  • 145k
4 votes

Oscillator Driven LED - Not Oscillating

Short: Short circuit Q1 C-E with metallic shunt on "bad" circuits. What happens? Review what's known: The CR2032 is being thrashed to far beyond its usual ratings and its voltage will sag to 2. …
  • 145k
5 votes

How does this diode compensate bias current change on a BJT due to temperature variation?

To read how he puts it look here - Temperature compensation of BJT differential amplifiers and start at the top of page 5. Reading pages 1 to 4 is probably good background preparation. …
  • 145k
1 vote
Accepted

MPSA42 confusion

Added: Any BJT with a base drive resistor becomes a "digital transistor". Any FET is a "digital transistor" Here is a Digikey list of FETS with Vds >= 300V in 10 quantity. …
  • 145k
6 votes
Accepted

The 'gap' between understanding of transistors and their application in real circuits

Buy this book The Art of Electronics by Horowitz and Hill (2nd edition). It cost $US20 (which is a bargain). It's in New Delhi and they have a number of them. If you cannot afford the 1050 Rupee get …
  • 145k
3 votes

BJT Pre-Regulator

As W5VO said, if you want to minimise energy loss then you need a switching regulator. If you want to minimise heat dissipation in the LM315 the probably cheapest solution is to add a resistor betwee …
  • 145k
0 votes

PNP transistor to command LED

Rushing. Diagrams later maybe., You should be able to draw this yourself from the following. Use two resistors. R1 from +5 to base. R2 from base to 0/3.3 Signal. R1 is say 10k R2 is say 39k - call …
  • 145k
1 vote
Accepted

Why is this current source with both sides grounded still supplying current

What happens INSIDE a current sink is what allows the zero Ohm link to simply carry the current generated with the internal potential. In any circuit that you deal with you would have no problem wit …
  • 145k
2 votes

How do I protect a sensor IC from overvoltage when not in use?

A relay is the easiest solution. Either DPST to switch sensor onto the inductor in circuit. or DPDT to switch the inductor out of circuit and onto the sensor. The latter arrangement gives full isolati …
  • 145k
0 votes
Accepted

Why does SOT89-ECB footprint exist?

... a part that has a footprint SOT89-ECB (PNP-BJT), ended up on my board, but when I tried to find a transistor that actually has compatible pin configuration I came out with nothing. …
  • 145k
4 votes
Accepted

Current source with IGBT

No. Not as shown without "select on test"ing. For input purposes an IGBT looks like a MOSFET. It will have a minimum gate voltage at which conduction begins and this will vary with the model of com …
  • 145k
11 votes
Accepted

FET vs bipolar junction transistor

If you wish to avoid holy wars you'll need to avoid making simplistic and incomplete statements :-). Bipolar transistors are current driven. MOSFETs are voltage driven. In both cases the spread …
  • 145k

15 30 50 per page