This is getting on my nerves....

Thread Starter

peck68

Joined Nov 27, 2009
73
GRR - this exact circuit was working a week ago, yet I have the urge to make one again today because I managed to find some transistors :)

Yet, the astable 555 circuit is acting as if it was a monostable circuit - it is only on for a second, then off indefinitely. I have to take out the battery for a few seconds and then connect it again to get the same effect.

:confused::confused::confused::confused:

It cant be the timer, since I have two - and must be sheer coincedence that BOTH timers broke. And even then, they couldn't have been broken since it is timing something, but not resetting itself...

I have built and the rebuilt and then rebuilt the circuit again, the same result ¬_¬

Attached i have the breadboard of what i am doing - i have tried extending as far as possible to make it clearer for you guys, along with the schematic.

Apart from that R1 is 10k, R2 is 150k and C1 is 10uF, and its not 1hz - its 0.5 ;)
 

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bertus

Joined Apr 5, 2008
22,270
Hello,

Jony130 is right.
Normaly pin 5 is connected to ground using a capacitor of 10 - 100 nF for decoupling.

Greetings,
Bertus
 

Thread Starter

peck68

Joined Nov 27, 2009
73
OH yeah that was the one thing i completely forgot about when i did it last time :D

Thanks a HUGE bundles :) i shall make changes now to that schematic

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@bill marsden - hmm, why is discharge disconnected? Anyway could be helpful later on

Thanks all
 
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