General > General Technical Chat
This Astable Multivibrator doesn't work
<< < (3/4) > >>
Labrat101:

--- Quote from: xzswq21 on June 04, 2021, 06:04:18 pm ---
--- Quote from: Labrat101 on June 04, 2021, 05:31:37 pm ---Personally I use a full Tester & or  Curve Tracer Test   :-+

--- End quote ---

What do you mean full tester? Could you please introduce me a curve tracer or a full tester?
Plus I have an idea, can I modify the circuit to generate a 1KHz pulse instead of a few Hz? I will see the output with an oscilloscope, is it more effective?
Thanks

--- End quote ---

https://www.kandh.com.tw/uploadfiles/592/Products/Testing-Instrument/KI-3020A/KI-3020A-Catalog/_en_ki-3020a_10801.pdf

I built my one Many moons ago years ago .  This one is about the same .  in fact looks very similar .
 There are quite a few circuit designs floating around read up on this they are not so complicated .
the transistor tester side uses an pulse staircase  design with XY out.The Mosfet is a lot different  as you can Not put
more than a few ua  on the gate only voltage.  & has a extremely high hfe . and when active switched will have a very
low internal resistance usually less than an Ohm between the source and Drain .

If you are a beginner    I would look at the  arduino component tester there was a whole project up on GitHub
which would get you on the right track and it tests all components and about 90% + accurate  .
and will recognise most MosFet's  , Transistors pnp npn ,caps ,diodes , resistors etc.
As I don't know what you want exactly . If you are starting out . which I guess you are  by the first Question.
 Or Look on Ebay etc there are component testers for less than $20 .. (Dave did a YouTube on 1 long time back)
If you have CRT scope then curve tracer will give you a visual  of what's what .

  Personally i am OLD school analogue only . Non of my test gear is newer than 15 years . My Tech scope is having its 35 birthday soon .  ;D

 I think that the arduino component tester would be good . its cheap and will give you fun building it and learning .
  :popcorn:

https://create.arduino.cc/projecthub/plouc68000/ardutester-v1-13-the-arduino-uno-transistor-tester-dbafb4
Labrat101:
UPdate ::
Read this it will explain how to build a curve tracer
it simple and it works well .
FET CURVE TRACER  (recommended)
http://eprints.utar.edu.my/88/1/EE-2011-0703010-1.pdf
Read the entire Document its a bit long as it explains how each section works
and how to use with examples .  the power supply is towards the end of doc

The one I built I added another row of DAC .. ie D1 to D6 . with a switch HI/Low so I could test
Power transistors
using the other outputs from IC1 4024. .. also adding another switch for 4 or 8 lines (traces)
Just make sure that the switch S1 & S2 are wired correctly as it will burn a Fet gate if tested
as a pnp or npn .  Recommend putting a separate socket for the Fet . as not to make error when
testing .

Enjoy
Zero999:

--- Quote from: Labrat101 on June 04, 2021, 05:31:37 pm ---
--- Quote from: Zero999 on June 04, 2021, 01:41:12 pm ---
--- Quote from: Labrat101 on June 03, 2021, 09:29:18 pm ---This tester No comment .
Quick & Dirty .

--- End quote ---
You might want to add a 1M to 10M gate-source resistor, otherwise the MOSFET's gate can pick up noise, causing the LED to flicker and, to avoid damaging the gate from ESD, always touch the source side first, before the gate.

--- End quote ---
@Zero999
That's WHY I wrote NO Comment .. Its a Demo ONLY. 
 Personally I use a full Tester & or  Curve Tracer Test   :-+

--- End quote ---
Why post it, if you didn't want anyone to comment?

Another improvement to that circuit would be to replace the finger, with a switch. A small gate resistor, say 1k would also be a good idea, to avoid short circuiting the supply, if the MOSFET's gate is damaged. Also note that the gate-source voltage rating of some small, low gate threshold voltage, MOSFETs is under 12V.
Labrat101:

--- Quote from: Zero999 on June 07, 2021, 07:43:13 am ---
--- Quote from: Labrat101 on June 04, 2021, 05:31:37 pm ---
--- Quote from: Zero999 on June 04, 2021, 01:41:12 pm ---
--- Quote from: Labrat101 on June 03, 2021, 09:29:18 pm ---This tester No comment .
Quick & Dirty .

--- End quote ---
You might want to add a 1M to 10M gate-source resistor, otherwise the MOSFET's gate can pick up noise, causing the LED to flicker and, to avoid damaging the gate from ESD, always touch the source side first, before the gate.

--- End quote ---
@Zero999
That's WHY I wrote NO Comment .. Its a Demo ONLY. 
 Personally I use a full Tester & or  Curve Tracer Test   :-+

--- End quote ---
Why post it, if you didn't want anyone to comment?

Another improvement to that circuit would be to replace the finger, with a switch. A small gate resistor, say 1k would also be a good idea, to avoid short circuiting the supply, if the MOSFET's gate is damaged. Also note that the gate-source voltage rating of some small, low gate threshold voltage, MOSFETs is under 12V.

--- End quote ---
@ Zero999
If only you had a Brain and could Read the whole subject you would have realised why I put it there
But I guess you only want to add Stupid remarks that are not only off subject but are not relevant or helpful in any way .
 The  diagrams that were added are 100% operation and also allow for modification .
 and Based on the Original Design . :-+
 
Have a good life,   and go Patent some thing ..
Halcyon:
I'm too tired for crazy. Play nice or I start deleting/locking stuff.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod