• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

how to solder on a board w/o circuit etched?

daviddoria

New Member
The NEW question:
now about the timer... since the pins are in such a wierd order... i was using little jumper wires to go across the IC, BUT it is really goofy cause i have like 8 little loops way down below my PCB. how am i supposed to solder the leads that need to go across the IC?

the OLD question:

how do i know which is pin 1 on the 555?

how do i know C-B-E on this square type of transistor? is the left when looking at the writing the collector?

please let me know

also, is it necessary to use a socket for a 555 timer?

david
 

kinjalgp

Active Member
The pin diagram of 555 is given below: Put the IC as shown and the pin just below the semi-circlular notch is pin 1. Also sometimes a small circle is given above pin number one. This standard is followed for all the ICs.
It is always better to use sockets for ICs as it is easy to replace it when blown.
 

Attachments

herbymcduff

New Member
what is your part number on your transistor?
 

daviddoria

New Member
thanks kinjalgp for the timer info.

herbymcduff, the transistor is TIP31c ( guess normally known as TIP31)

thanks guys
david
 

daviddoria

New Member
also, is it normal in a schematic for the numbers to be out of order on the IC? like this

2
1 ---------7
5 | |
8 | |4
3 | |6
|--------

is it just easier to draw like that?
 

herbymcduff

New Member
yes it is normal, maybe not easier, but it just depends on who draws the schematics.
 

daviddoria

New Member
ok, i'll try wiring the timer with the leads to the right number, not the position of the number,

also, hahaha that is my transistor, but i'm assuming that the diagram is looking from the perspecitive that you can see the writing on the transistor?

also, isn't the base usually in the middle?

does BUMP work in this forum? just a test ;)

david
 

herbymcduff

New Member
it is BCE. So the square part in front of you it goes in that order. The tab is also C.

Pin 1=Base
Pin 2=Collector
Pin 3=Emitter
Tab=Collector
 

daviddoria

New Member
excellent on the transistor.

now about the timer... since the pins are in such a wierd order... i was using little jumper wires to go across the IC, BUT it is really goofy cause i have like 8 little loops way down below my PCB. how am i supposed to solder the leads that need to go across the IC?

thanks
david
 

kinjalgp

Active Member
No circuit has straight-forward connection. Loops are always there. If you are using general purpose perf-board then solder all the componenets nearest to the IC's pins so as to have minimum jumpers. Or the other alternative is to use PCB.
 

Latest threads

EE World Online Articles

Loading

 
Top