Please help me understand this circuit and how it works

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my dears 

We will consider that 1-2-3-4-5.......14-15 as switches connect to base of transistor and 

collector of 1-2-3-4-5 connect to together and connect pin 30 micro and 

collector of 6-7-8-9-10 connect to together and connect pin 37 micro and

collector of 11-12-13-14-15 connect to together and connect pin 36 micro and

emitter 1-6-15 connect to together and connect pin 35 micro and

emitter 2-7-14 connect to together and connect pin 34 micro and

emitter 3-8-13 connect to together and connect pin 33 micro and

emitter 4-9-12 connect to together and connect pin 32 micro and

emitter 5-10-11 connect to together and connect pin 31 micro and

using pic18f67k40 or any pic 18f

like as picture 

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ARe you serious or plain lame??...get a grip and draw a schematic that describes what ever long list of connections you are providing.  No description of connections should be needed, or presented , just your finished schematic.

Also, why are you creating a schematic that you have no idea of what it does?   What have you done so far in figuring it out? You are not in the proper forum; this is the AVR forum, so best to perhaps go there instead.  

 

What the circuit does:  It switches a bunch of transistors or or off.  Current is only allowed to flow outward   The voltages avail are 12v, uc36, uc37 (neglecting drops)

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

Last Edited: Sat. Dec 14, 2019 - 05:30 PM
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i'm sorry but it's apart from elevator project in the old we used 2 74hc151 and connect the select line to micro and outputs to micro and we wrote the code and work but the doctor said remove the 2 151 and use this circute  

he want when press switch 1 write on lcd lvl ok 

                     press switch 2 .... and so on 

                     how the micro feel when the press switch 1 muste be put all collector 5 v? or what 

 

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i'm sorry but it's apart from elevator project

I doubt anyone will take a chance on riding your elevator if you can't even draw a schematic...spend some serious time and come back with a schematic of what you are doing, not some "old " schematic of what you are not doing.

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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So, in May of last year the OP starts a thread about gcc and it has to do with the 74151 and connecting to a Mega8, and now a year and a half later starts another thread regarding connecting a boatload of transistors to a micro to replace two 74151's because the doctor told him to.

Get a new doctor to help you with your homework assignment.

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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Will it work? The first step is to make a statement of what you want to achieve.
My guess is you have a number of pushbuttons you want to read using the smallest amount of port pins.

It seems the pushbuttons are connected to 12V and have a led in series.

The next step is to draw a decent schematic - this can be hand drawn, but it must be readable. Yours is a scribble i’d do as a first pass for myself. There’s also some resistor values - how were they arrived at? If it were my scribble I have current flow arrows and current values along with some ohm’s law.
Having uc pins makes no sense to us - how do we know what those pins are?
Then do some circuit analysis- redraw a section and put voltages to the nodes. Analyse the outcome. You only need basic transistor theory and ohms law.
The outcome of this will tell you if there is hope it will work or not.

Remember - the quality of the answer is based on the quality of the question. Ie: ask a good question as in a question that is clear and concise and you’ll most likely get a good answer. Your question is wishy-washy but yet you want a precise answer.
Ask yourself why using a handful of transistors/diodes would be preferable to using some multiplexer ics? Cost? Manufacturability? Testing?

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Kartman wrote:
Ask yourself why using a handful of transistors/diodes would be preferable to using some multiplexer ics? Cost? Manufacturability? Testing?

 

The "Doctor" told him to:

engmahmoud wrote:
we wrote the code and work but the doctor said remove the 2 151 and use this circute  

 

Don't waste your time on this Russell....not worth it.

 

Jim

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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You must sequentially activate pins 30-36-37 (collectors)
  and read pins 31-32-33-34-35.
 
That is:
Pin30 act: Read switchs 5- 4- 3- 2- 1
Pin36 act: Read switchs 11-12-13-14-15
Pin37 act: Read switchs 10- 9- 8- 7- 6

---------------------

- In that circuit all the diodes are unnecessary, the base-emitter and collector base junction itself behaves like a "diode" preventing reverse currents when are several switches actives (warning, this is true with 5V)

- Neither 2.2k resistors are necessary

- But... pulldown resistors are required at inputs 31 ... 35, otherwise incorrect readings will be taken due to the base current of the transistors and the mcu pulldown resistors will not be enough.

 

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So you have a 5x3 button matrix (I guess this is the elevator's button panel) and want to read the buttons using multiplexing?

You need to use the proper terminology to describe the problem. People will be less disposed to help if they have to decipher your scribblings first.

 

Ok, here is your suggested reading:

http://blog.komar.be/how-to-make...

https://www.dribin.org/dave/keyb...

http://www.openmusiclabs.com/lea...

https://deskthority.net/wiki/Rol...

Last Edited: Sun. Dec 15, 2019 - 02:01 PM
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jgmdesign wrote:

Kartman wrote:
Ask yourself why using a handful of transistors/diodes would be preferable to using some multiplexer ics? Cost? Manufacturability? Testing?

 

The "Doctor" told him to:

engmahmoud wrote:
we wrote the code and work but the doctor said remove the 2 151 and use this circute  

 

Don't waste your time on this Russell....not worth it.

 

Jim

 

think you all missed out on another small detail:

 

 

engmahmoud wrote:

using pic18f67k40 or any pic 18f

 

so not AVR related at all.

 

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meslomp wrote:
so not AVR related at all.

 

I saw it, but the question is general electronics and the question more specifically about the transistors so I ignored the PIC part.

 

Good catch though.

 

JIm

I would rather attempt something great and fail, than attempt nothing and succeed - Fortune Cookie

 

"The critical shortage here is not stuff, but time." - Johan Ekdahl

 

"Step N is required before you can do step N+1!" - ka7ehk

 

"If you want a career with a known path - become an undertaker. Dead people don't sue!" - Kartman

"Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?"  - Lee "theusch"

 

Speak sweetly. It makes your words easier to digest when at a later date you have to eat them ;-)  - Source Unknown

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB, RSLogix user

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engmahmoud wrote:
the doctor said remove the 2 151 and use this circute

So get the "doctor" to explain his circuit to you!

 

 

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eating an AVR a day keeps the "doctor" away

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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avrcandies wrote:
the "doctor" 

"doctor" who?

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...