Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

mistake in the diagram - please help

Status
Not open for further replies.

newbie111

Member level 2
Joined
Nov 29, 2009
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
h.k
Activity points
1,616
mistake in the diagram

hi pal,

the 2 ( 7 segment displays) are common cathode type

so there are something wrong with the schematic.

T1 and T2 collectors and emitters are wrongly reversed

and should r3 and r4 be pull UP resistor ?

vcc --pull up resistor---- transistor emitter ----switch------ground

(transistor collector goes to the cathode of the 7 segment)

when the transistor is on and the button is pressed (brings it to the ground) to activate the 7 segment display


I am learning electronics as my hobby.

excuse me

Folks, please kindly tell me whether my analysis is right or not.

Thank you so much!
 

pranam77

Advanced Member level 5
Joined
Apr 22, 2008
Messages
2,786
Helped
552
Reputation
1,102
Reaction score
371
Trophy points
1,363
Location
INDIA
Activity points
16,418
mistake in the diagram

The given circuit is perfect. The displays are common anode type, switched through the NPN transistors with thier collectors connected to Vcc. PIN 2 and 4 are pulled to Vcc through 10K resistors and when the push button is pressed, the same get pulled LOW to increment or decrement the values. The symbol you are assuming as ground is actually a Vcc symbol. Only minor mistake i noted is that R1 and R2 may be 330E upto 1K instead 330K ..... Cheers
 

    newbie111

    Points: 2
    Helpful Answer Positive Rating

newbie111

Member level 2
Joined
Nov 29, 2009
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
h.k
Activity points
1,616
Re: mistake in the diagram

Thanks for your great answer.

The guy said the 7 segment displays are common cathode type tho


here is what he said:

This is a screen shot of the final assembly (yes, i soldered 2 flags )

To build this board you need 2 330Ω, 7 220Ω and 2 10KΩ resistors, 2 NPN transistors, a PIC16F690, two 7 segment display (i used in my build a common cathode, if you use a common anode you have to change the schematics and code a little) and 2 push buttons.



Here is the link
http://www.protung.ro/2009/09/simple-score-board-with-pic16f690-7-segment-display/#comments

If the 7 segment displays are common cathode type
then how should we fix his schematic?


Thanks

Added after 14 minutes:

Only minor mistake i noted is that R1 and R2 may be 330E upto 1K instead 330K<---

Sorry

why 330E to IK?

How did you get this figure?

Thanks
 

pranam77

Advanced Member level 5
Joined
Apr 22, 2008
Messages
2,786
Helped
552
Reputation
1,102
Reaction score
371
Trophy points
1,363
Location
INDIA
Activity points
16,418
Re: mistake in the diagram

newbie111 said:
If the 7 segment displays are common cathode type
then how should we fix his schematic?
You cannot use any other type of display than mentioned as the firmware in the pic is serving all the cathodes of the same. To change the display, the code should be complimented to drive anodes or all the output pins of the PIC micro needs to be inverted by an inverter like CD4069.

newbie111 said:
why 330E to IK? How did you get this figure?
I have not calculated it. I have just guessed it with my practical experience. BTW the author has mentioned the use of 2 x 330E. Thaz it. You may ask the author for a better answer about how he designed it. Cheers
 

    newbie111

    Points: 2
    Helpful Answer Positive Rating

newbie111

Member level 2
Joined
Nov 29, 2009
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
h.k
Activity points
1,616
Re: mistake in the diagram

Thank you for everything, pal.


Great help!
 

hugo00

Member level 2
Joined
Jun 2, 2005
Messages
51
Helped
18
Reputation
36
Reaction score
18
Trophy points
1,288
Location
Au
Activity points
1,674
Re: mistake in the diagram

newbie111 said:
hi pal,

the 2 ( 7 segment displays) are common cathode type

so there are something wrong with the schematic.

T1 and T2 collectors and emitters are wrongly reversed

and should r3 and r4 be pull UP resistor ?

vcc --pull up resistor---- transistor emitter ----switch------ground

(transistor collector goes to the cathode of the 7 segment)

when the transistor is on and the button is pressed (brings it to the ground) to activate the 7 segment display


I am learning electronics as my hobby.

excuse me

Folks, please kindly tell me whether my analysis is right or not.

Thank you so much!


Hey did you do something in electronic or you just COPY the ideas and design from someone else??
 

newbie111

Member level 2
Joined
Nov 29, 2009
Messages
51
Helped
1
Reputation
2
Reaction score
1
Trophy points
1,288
Location
h.k
Activity points
1,616
Hugo,

I guess you mean electronicS. I do love it and study people's designs as a learning process. Is it wrong to do so?


You did not need to ask me such a you know what question and capitalize the word
"COPY". ** I am incapable of changing people's designs as my own since I am a rookie.***

It was so rude to say that to someone who is willing to learn this subject.

Once again, I am saying thank you to anyone who has ever answered my questions in this forum.


Regards,

Newbie111
 

keith1200rs

Super Moderator
Staff member
Joined
Oct 9, 2009
Messages
10,877
Helped
2,064
Reputation
4,128
Reaction score
1,597
Trophy points
1,403
Location
Yorkshire, UK
Activity points
57,276
Ignore the offensive comments of hugo00. It is fine to use freely published material to build and learn. Without it there would be very few people around here with much to say!

Keith.
 

    newbie111

    Points: 2
    Helpful Answer Positive Rating

abbeyromy

Full Member level 4
Joined
Feb 2, 2010
Messages
194
Helped
26
Reputation
50
Reaction score
7
Trophy points
1,298
Location
US
Activity points
2,708
@newbie111
Dont be bothered with negative energy around. You are doing a great job! It is always a good practice to first understand proven designs in order to learn the concept practically and then play with design parameters in order to make something new.. Nothing wrong with that buddy...
There are lot of people on edaboard who will support you in your learning process..
All the very best!
-Hemanshu
 

hugo00

Member level 2
Joined
Jun 2, 2005
Messages
51
Helped
18
Reputation
36
Reaction score
18
Trophy points
1,288
Location
Au
Activity points
1,674
Hugo,

I guess you mean electronicS. I do love it and study people's designs as a learning process. Is it wrong to do so?


You did not need to ask me such a you know what question and capitalize the word
"COPY". ** I am incapable of changing people's designs as my own since I am a rookie.***

It was so rude to say that to someone who is willing to learn this subject.

Once again, I am saying thank you to anyone who has ever answered my questions in this forum.


Regards,

Newbie111

Hello,

Sorry about my negative comment, please take my APOLOGISE for it.

Regards,
Hugo
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top