How to trigger a 555 mono with a +ve pulse?

Thread Starter

onlyvinod56

Joined Oct 14, 2008
362
hello,
This is a cascaded multi level inverter.
Iam trying to design a firing circuit based on 555 monostable, 555 astable, NOT gate, and optocouplers.
see the attachments

attachment 1: schematic of 2 level cascaded multi level inverter

attachment 2: firing scheme

attachment 3: my problem

How can i trigger the monostable with the pulse shown in attachment 3??

thankyou
 

Attachments

Wendy

Joined Mar 24, 2008
21,840
Just double checking, you want to trigger a 555 monostable with a positive going pulse? A simple transistor inverter in front of a conventional monostable would do this, or any inverter for that matter.

 

Thread Starter

onlyvinod56

Joined Oct 14, 2008
362
Just double checking, you want to trigger a 555 monostable with a positive going pulse? A simple transistor inverter in front of a conventional monostable would do this, or any inverter for that matter.

ThanQ Bill_Marsden

And one more question (just for conformation)
How can a long duration pulse can be converted into a spike using RC circuit?? see the attachment

Can u post the schematic
 

Attachments

Wendy

Joined Mar 24, 2008
21,840
Direction of flow for schematics is important, it can make a schematic hard to read or easy.

Basically the capacitor charges up, and no more current flow, so the resistor then predominates.
 

Thread Starter

onlyvinod56

Joined Oct 14, 2008
362
Direction of flow for schematics is important, it can make a schematic hard to read or easy.
OK.
It is a part of the schematic. Thats why the direction is reverse.

Basically the capacitor charges up, and no more current flow, so the resistor then predominates.
And, I got your point. I have done the simulation.
Thank you Mr. Bill_Marsden
 

Attachments

Top