• 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.

TTL gate to 2n2222

Status
Not open for further replies.

aikiko

New Member
Hello,

I am making a little circuit to switch audio sources and it is many years that I haven t used electronic... How do I calculate the value of the resistor :



I hope the design is ok ?
This is only the usefull part of my design.

Thank you for you help.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
No, the design is completely (and self destructively) wrong.

The relay must be in series with the collector, and MUST have a protection diode across it.

Check out the relay example in my tutorials

Nigel's PIC Tutorial Hardware Extras

The resistor isn't critical, it needs to be low enough to switch the transistor fully, and high enough to not overload the chip.

Try something like 1K for a start.
 

aikiko

New Member
First of all thanks for you fast reply.

I did not notice that the design was completely wrong, thanks for make me paying attention that it was completely wrong...



Now this is fixed i would like to ask you another ting : do you know if logic or gates can be found with a clock/enable signal ?

Thanks
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading

 
Top