# Switching 12v

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Little to nil knowledge of digital  logic.
I need to switch 12v at say 100ma across 10 wires at around 1sec each . I
must be able to start and stop the switching by applying around10v.
(No not an assignment, I need to do it for me :)
Could anyone point me to a webpage /circuit design source please ?

Cheers
Jim

Re: Switching 12v

There was this little invention a few years ago called the transistor that
might help :-)

Michael

Re: Switching 12v

Yep, 1947 I seem to remember. Before even I was born :)
Strangely enough I was asked where a guy could get some background on valve
theory the other day. They may be gone but they apparently aint dead :))

Cheers
Jim

Re: Switching 12v

I've got a series of rather large glowing valves just a few metres from me.
Not many transistors putting out 3kW just yet.

Cheers.

Ken

Re: Switching 12v

I'm still running a valve amp that must be over 35 years old. My parent's
bought it before I was born. The amount of heat it puts out just sitting
idle is amazing.

Michael

Re: Switching 12v

Check out this site; the link goes straight to the circuit you want
(substitute relays for the LED's - see the section in the site for
interfacing relays to logic gates).
http://ourworld.compuserve.com/homepages/Bill_Bowden/page5.htm#4017-2.gif

Cheers.

Ken

Re: Switching 12v

Hi Jim,

I am assuming you want the 10 wires to "take turns" at being energized?
If so, have a look at this site:

It has 10 outputs (via a 4017 Decade Counter IC) which take turns one at a
time.  It requires a clock input (high/low) to time the outputs.  Instead of
LED's connected to each of the 10 outputs of the IC (like that shown on the
site), you can connect a resistor and transistor to each of the outputs to
switch current such as 100mA.  If you're not familiar with this, I have
http://www.kpsec.freeuk.com/trancirc.htm#chip - "Connecting a transistor to
the output from a chip".

Hope this helps.

Jason.

Re: Switching 12v

and the clock source 555 ic or whatever can be powered by the 10v signal

Re: Switching 12v

Many thanks guys, the help is appreciated :))

Cheers
Jim