transistor designator

[red devil]

i got this ckt i getting problems in making connection of 7 segment to the ic can any one help me....

 

[Mike_2545]

That is the circuit I gave you. Just connect the pins as described.

 

[red devil]

mike first i wanna ask tht which type of segment would be gud common cathode or anode....
secondly in ur ckt segment A is connected with 5 v batterey and A B E F are short with each other am i right??

 

[Mike_2545]

Here let me google that for you: Let me google that for you

 

[Mike_2545]

You should also use seperate resistors per segmenet. That drawing is from 1975.

 

[red devil]

thnx mike and by the way what is the value of capacitorwhich is connected in pin 2 of 555

 

[red devil]

don't u have its modified or more clear form as it is from 1975

 

[Mike_2545]

You want me to Google that too?

Try a .15mF disk cap like I have in the drawing. It will give you a nice fast pulse.

 

[Mike_2545]

No I don't. You are the student. You can do some of the work.

 

[red devil]

no dont google that

 

[red devil]

ok mike
i'll do the rest of the work. and from where u got that circuit

 

[Mike_2545]

In some of my notes.

 

[red devil]

hey what is the display cathode in figure???

 

[Mike_2545]

N= npn
P=pnp
A=open
R=short

Just like the notes tell you

 

[red devil]

hey mike i am getting the default in which segment a b e f are working but if i am inserting either npn or pnp transistor none of segment g or c is getting on ...

 

[Mike_2545]

Recheck it: it works fine.