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555 PROBLEM

J

Junkmail789

Jan 1, 1970
0
I got my 555 timer circuit working it's .3 sec per cycle. Problem is I'm
driving a relay that is 5 volts and the timer barely even lights a test LED
I hook up to it. Do I need to run a separate power line besides the output
of the timer to a relay?

I'll do some more research today but if anyone has a place to start it would
be appreciated.
 
C

CFoley1064

Jan 1, 1970
0
I got my 555 timer circuit working it's .3 sec per cycle. Problem is I'm
driving a relay that is 5 volts and the timer barely even lights a test LED
I hook up to it. Do I need to run a separate power line besides the output
of the timer to a relay?

I'll do some more research today but if anyone has a place to start it would
be appreciated.

This should do the trick. You need protection from the inductive kick of the
relay, and the 555 drive current may not be enough to drive the relay. If your
relay coil is less than 100 ohms, you might want to do something else. The two
resistors coming from pin 3 of the 555 could be 1K to 2.2K.

View in fixed font (M$ Notepad)

VCC VCC VCC VCC
+ + + +
| | | |
.-. 8| 4| |
| | .---o---o----. o------.
| | | | | |
'-' | | | |
| | | - |
| 7 | | ^ |
o----o | | _|_
| | | | RY1|_/_|-
.-. | |3 | |
| | | 555 o----. o------'
| | 6 | | | |
'-'.--o | | |
| | | | .-. |
| | | | | | |
o-o--o | | | '---o
| 2 | | '-' |
| | | | |/
--- | | o-----o Q1
--- | | | |>
| '---o--------' .-. |
| 1| 5| | | |
| | --- | | ===
| | --- '-' GND
| | | |
| | | |
| | | |
=== === === ===
GND GND GND GND



created by Andy´s ASCII-Circuit v1.24.140803 Beta www.tech-chat.de

Good luck.
Chris
 
B

Brian Oakley

Jan 1, 1970
0
You could always use a transistor on the output of the timer to drive the
relay.
Brian
 
B

Brian Oakley

Jan 1, 1970
0
How can I see your schematic drawing properly?
Brian
 
C

Chaos Master

Jan 1, 1970
0
Brian Oakley said those words of wisdom from the arcane mages in
sci.electronics.basics:
How can I see your schematic drawing properly?
Brian

Copy and paste it into Notepad.
 
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