Its possible to pause 555 Timer IC's Output?

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In generally 555 Timer IC's output(3 no pin) goes to High and Became low depends on RC Timing constant.

 

In a case i'm want to freeze 555 Timer IC's output.

A certain timer Later when outputs goes to High and it will be High forever.

শূন্য  - The ZeRo

Last Edited: Fri. Jun 17, 2016 - 04:27 AM
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You can do just about whatever you want to do with a 555 snd it's probably been already done before. You just need the voltage to stay above 1/3 vcc.

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If the voltage on pin 6 (connected in this configuration to pin 2) is made lower than 2Vcc/3 while the output is high (by pulling it down via a resistor of a suitable value and an npn transistor, for example), the output would stay high.

 

Also, if the control pin 5 is connected to Vcc (via a pnp transistor for example), the capacitor voltage may not reach the new high level of pin 5 (which was 2Vcc/3 when open) to return the output back to its low level (please note I didn't test this yet).  

Last Edited: Fri. Jun 17, 2016 - 05:23 AM
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Left field suggestion: replace 555 with small 8bit micro then you can make it generate whatever pulse pattern you program :-)