556 timer problem

K

Thread Starter

kirkyj78

Joined Jan 19, 2008

7

Jan 19, 2008

• #1

Hi, can anyone help me i am using 556 timer to turn an led on for 2 mins & to turn a relay on for 30seconds which in turn switches a solenoid on, the problem i have is when the solenoid switches it causes the timer to reset or switch off, i do have a diode in reverse across the relay and another from the output of the 556 timer, i guess EMF is the problem, i just don't know how to solve it?????

thanks

 

hgmjr

Joined Jan 28, 2005

9,027

Jan 19, 2008

• #2

Can you post a copy of your schematic?

hgmjr

 

SgtWookie

Joined Jul 17, 2007

22,230

Jan 19, 2008

• #3

The bipolar version of the 556 can sink up to 200mA, the CMOS version sinks less.

What is the exact part number of your 556?

How much current does your relay's coil require?

What are you using for a power supply?

 

G

gee_emm

Joined Jan 16, 2008

34

Jan 20, 2008

• #4

Im pretty new to electronics myself, but maybe you can use an optoisolator between the 556 and relay, to kind of keep them electrically seperated. I discovered them after blowing up a basic stamp.

 

K

Thread Starter

kirkyj78

Joined Jan 19, 2008

7

Jan 20, 2008

• #5

hi,
Thanks for the reply's

the chip is an Ne556n
12v dc

The problem is the solenoid even though it is driven through a relay.

If i disconnect the solenoid the circuit work's fine.

thanks

 

K

Thread Starter

kirkyj78

Joined Jan 19, 2008

7

Jan 20, 2008

• #6

hi, how do i put a circuit diagram on here, i used pcb wizard to design it so it would not be in the correct format.

 

hgmjr

Joined Jan 28, 2005

9,027

Jan 20, 2008

• #7

Does you design software permit you to save or export the file into PNG, JPG, or TIFF format?

hgmjr

 

K

Thread Starter

kirkyj78

Joined Jan 19, 2008

7

Jan 20, 2008

• #8

no unfortunatly not, i wondered if i should print it then scan it and save it in a different format, seems a long way of doing it though

 

hgmjr

Joined Jan 28, 2005

9,027

Jan 20, 2008

• #9

kirkyj78 said:

no unfortunatly not, i wondered if i should print it then scan it and save it in a different format, seems a long way of doing it though

Click to expand...

That should work. Why don't you give it a try?

hgmjr

 

Ron H

Joined Apr 14, 2005

7,063

Jan 20, 2008

• #10

You can download any of a number of freeware or shareware screen capture programs to get around having to print and scan.

 

SgtWookie

Joined Jul 17, 2007

22,230

Jan 20, 2008

• #11

If you're using Windows, you can capture a screen shot like this:
1) Get your screen how you want it to look.
2) Hold down the Ctrl key and tap the PrtScr key
3) Start Windows Paint (in Accessories)
4) Edit/Paste or Ctrl+V
5) File/Save As...
I suggest saving it in either .jpg or .png format, as the resulting file size will be much smaller than the other formats.

 

JoeJester

Joined Apr 26, 2005

4,390

Jan 20, 2008

• #12

You can capture the active screen with alt-prnt scrn, then paste it into paint, then save as a jpg or gif or png.

ctrl-prnt scrn will place your whole desktop on the clipboard for pasting.