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Please, I need simplest possible monostable circuit (with like NE555, 74121, 74123 etc.) that will provide output like in this diagram .I am wanting to limit the time that the output is high irrespective of how long the input is high .Would a simple RCD differentiater do the trick?

enter image description here

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    \$\begingroup\$ Please define "simplest". Cheapest, smallest, fewest parts, ...? \$\endgroup\$ – uint128_t Jan 10 '16 at 1:50
  • \$\begingroup\$ The shortened pulses will be the tricky part. \$\endgroup\$ – Ignacio Vazquez-Abrams Jan 10 '16 at 2:03
  • \$\begingroup\$ @IgnacioVazquez-Abrams Without the shortened pulses a wire would work. \$\endgroup\$ – Spehro Pefhany Jan 10 '16 at 3:10
  • \$\begingroup\$ @SpehroPefhany: I mean the first and fourth pulses in the diagram. \$\endgroup\$ – Ignacio Vazquez-Abrams Jan 10 '16 at 3:15
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The solution to this circuit design request should be pretty easy. Use a half of a dual non-retriggerable monostable multivibrator such as the Fairchild 74VHC221A. Connect it up like this:

enter image description here

The circuit will use the two states highlighted in the truth table.

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D1 may not be necessary; may already be present in internal circuit of AND gate.

schematic

simulate this circuit – Schematic created using CircuitLab

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  • \$\begingroup\$ This is also a good solution but I guess would require some input buffer with low resistance output and that would require extra components \$\endgroup\$ – 69676F72 Jan 10 '16 at 14:16
  • \$\begingroup\$ Perhaps -- but the OP didn't have any other information about the system. \$\endgroup\$ – jp314 Jan 10 '16 at 16:24
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This might work as well:

Picture of circuit

Simulate circuit in Falstad

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