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did you try it ??
555 timer self reset.
- Thread starter sahil-siwatch
- Start date
Where did you find that circuit? Can you share links ?
If you have time, Can you please add RC on your trig and dis pins and see what happens..it will be a big favour. Only if you have time
thanks in any case for your time. Best Regards
Last edited by a moderator:
Just completed and it works as described. R1 = 1M, C3 = 10uf..... shuts off after 11 seconds
Thank you so much.
but when you press button...does it shut off?? Will it be possible to make a video somehow and mail it to me?
I am sorry for your troubles
you will see my id on my circuit. renamed it and battery is also named as my id https://www.multisim.com/content/uGjVW7HiACX9TKujNtZDrG/sahilsiwatch07gmailcom/open/
You can try this.I am new to working on 555 timer. I am running it in monostable mode. I am triggering it using a button on trigger pin. It works just fine. What I want is the LED connected to the out pin 3 to switch off when I press the trigger button again. If I don't press the button, LED will switch off after the specified time duration by the RC circuit. Is it possible? Thanks in advance.
I haven't bread boarded this but it works in simulation.
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ElectricSpidey
- Joined Dec 2, 2017
- 3,335
I worked up a sim of the idea I mentioned in Post#11.
First push under .3 second starts timer.
Second push .5 second or longer stops timer.
I also did not breadboard the circuit, and I used the ideal 555 model, so that may affect results, but circuit requires only passives.
First push under .3 second starts timer.
Second push .5 second or longer stops timer.
I also did not breadboard the circuit, and I used the ideal 555 model, so that may affect results, but circuit requires only passives.
I used the simulator link you sent me and corrected the schematic as needed. Set R1 at 100K.... C3 at 5uf.....C1 at 1uf....R3 at 100K.
LED turns on with switch and shuts off after several seconds. That's working correctly.
When the switch is pushed a second time the LED shuts off but comes right back on when the switch is released.
That is not what's happening in the actual circuit. The simulator is not accurate in this detail.
When the switch is pressed a second time the voltages on the RST and TRI pins during simulation are correct but the output is not responding correctly on the simulator.
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Okay. Thanks for your help
I am sure it will work if I try it on breadboard. I will try that soon. Did you use the same MOSFETs used in the circuit i.e 2n7000G ? I got the changes that you told me but please post a screenshot of the design as the changes that you made doesn't show on the simulator on my end. I should probably try it on LTSPICE as well. But thanks anyway for your efforts. I appreciate that.
Thanks for the design. I will try this probably
I tried the circuit today. Same as we discussed earlier. It's not working. Only thing that was different was the MOSFET. I used IRF540 instead of 2N7000. Could it be anything wrong about the MOSFETs? I checked the gate threshold voltage. Seems okay.
breadboard
It works same as in the simulation. Monostable is starting but the second button push doesn't switch the LED off.
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