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556 Timer Issue

I am having an issue with the enclosed circuit provided. The issue that I am having is with component U2B reset pin. In the current condition the resets are tied together. U2A and U2B turn on once the voltage on the reset signal line reaches approx 2.5v.

 

The thing that i don't understand if i tie (U2B) reset to VCC the circuit stalls and eventually errors out. What i was expecting to see with (U2B) tied to VCC is  an output of approx 5.50Volts on (U2B) output, then once (U2A) starts oscillating it would trigger (U2B) into to oscillation as well giving me an oscillating Output on (U2B) opposite of (U2A) Output.

 

I am guessing that something is setup or wired wrong with (U2B). Any help or opinions will be appreciated.

 

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Hi,

 

I ran a simulation on your circuit with Multisim 12 and it seemed to be working. Attached is the waveform I captured.

 

Derek Z.
National Instruments
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