To simulate the monoshot, I gave inputs from an exponential power supply manually with current limits set at 10mA, 40mA or 100mA.

This doesn't make sense. How do you expect to get defined voltage steps by setting current limits on a power supply? And what is an exponential power supply?

We need to see a schematic.

 

We need proper English.

1ms pulses are almost too short for a lousy old LM324 opamp. I thought your input was 5VDC.

I do not know what is "an exponential power supply" and I also do not know what is "0.5V stepped out". Why are you limiting the input current when the input current is extremely low?
SEE? I cannot understand what you say!

If you apply 2.0VDC to the input of the circuit then the output will also be 2.0VDC.

 

Your circuit is not working properly probably because you swapped the emitter and collector pins of the transistor.

As audio guru told, it was my mistake. I got interchanged the collector and emitter.Thanks guru. Now I rectified the problem and the output follows input.

See the attachment for my project.

1. First I have implemented LM324-2N2222 portion without R9 and 50K on a bread board

2. Set supply at 10V with 200mA current limit

3. Gave inputs to the 3rd pin of Op-Amp using a dc source and varied the dc volts in 0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,& 5 to simulate variable mono pulses

4. WoW! output following the input with saturation occurs at 7.77V

5. Connected the 100R resistor network as shown in the figure with one end at ground and other end connected to dc source(set at 5V) mentioned in 3rd point to simulate the mono pulse

6. Connected voltage legs of the ladder directly to 3rd pin of Op-Amp without 50K.

7. WoW! output following the input for 0,0.5,1,1.5,2,2.5,3,3.5,4,4.5,& 5 at different positions of the resistor ladder

8. Tomorrow I am going to implement 1ms 555 monoshot or 1ms 74123 monoshot(additional 7805 IC needed to power it) on separate bread board and will cascade all three sections(1ms monoshot + Resistor ladder + Op-Amp_BJT) to form the final project. Hope it will work fine.

ANOMALIES OBSERVED:

1. 50K is rejected intentionally and connected the voltage legs of the ladder to the Op-Amp directly. This is to avoid the disturbance to the ladder resistors when 50K comes in parallel to them as I want exact 0.5V divisions of 5V.
But this causes the emitter volatge to goes to saturation(7.77V) when 3rd pin of Op-Amp not connected to any points.(floats)
To avoid this can I connect a high value resistor like 100K between 3rd pin and ground permanently without disturbing both ladder and Op amp.

2. 1ms pulses are almost too short for a lousy old LM324 opamp.
Which Op Amp should I use to transfer 1ms varying amplitude pulses to load fluently with 0 to 5 volt in/out capacity ?

 

I am glad that you fixed the wiring and got good results.

There are thousands of modern rail-to-rail opamps in The West that are much faster than the lousy old LM324 but they are probably not available in India.

Most opamps today have a frequency response/slew rate 50 times higher than the LM324 but they need a dual polarity supply. Can you add a negative supply to your circuit?

 

Most opamps today have a frequency response/slew rate 50 times higher than the LM324 but they need a dual polarity supply. Can you add a negative supply to your circuit?

Yes I can add a dual supply.

 

I use TL07x opamps (Texas Instruments but many manufacturers make them) for audio. They are the TL071 single, TL072 dual and TL074 quad low noise audio opamps. The TL08x opamps are the same but might have higher noise.
They work perfectly up to 100kHz. They need a dual-polarity supply or must be biased at half the supply voltage. The lousy old LM324 has trouble above 2kHz.

I use Motorola, ON Semi or Freescale Semi MC3317x low power 35kHz opamps or MC3407x normal power 100kHz opamps to replace the LM358 and LM324 opamps.

 

2. 1ms pulses are almost too short for a lousy old LM324 opamp.

I have trouble believing that. According to the TI datasheet, the typical slew rate is 0.5v/usec (see attachment). This will yield 10usec rise and fall times for a 5V pulse. Even if it is only 1/10 that fast, a 1ms pulse should be no problem.

 

The lousy old LM324 has trouble above 2kHz.

But I use 1ms single pulses produced by pressing the trigger switch once and next pushing may or may not be done as per the requirement of output pulse randomly.

That is there is no specific period for the pulses and the differentiator for triggering is designed for choosen period of 625ms >> 1ms.

 

The lousy old LM324 was made as the FIRST low power quad opamp. This makes it SLOW.
The output will slowly ramp up instead of switch up.
It might not get high enough before it must slowly ramp down.
The output will not be a square pulse. Instead it will be a triangle.

Try it to see.

 

I use Motorola, ON Semi or Freescale Semi MC3317x low power 35kHz opamps or MC3407x normal power 100kHz opamps to replace the LM358 and LM324 opamps.

MC34074 can be used in single supply and dual supply config. But in its datasheet there is no point to mention whether its is rail in/ rail out or not.

But states in dual supply its output can swing from -ve to +ve but what about input ? I want 0-5v variation in both in & out.
* Large output voltage swing: -14.7V to +14V
(with +-15V supplies)

 

I tested the circuit with a lousy old LM324 made by TI. I used a 33Ω load. The output slewed from 0 to 5V in 16usec, and from 5V to 0V in 16usec.
I'm not saying that all LM324s will slew this fast. I'm just sayin'.

 

The MC3407x opamps have inputs that work all the way down to the negative supply which can be ground. Just like the LM324. Its output goes all the way almost down to ground. Just like the LM324. They both can work with a single supply.

But its output and its inputs cannot go as high as the positive supply, they go to about 1.2V less. Just like the LM324.

But the LM324 has crossover distortion. The MC3407x opamps have none.

The LM324 has trouble above 2kHz.
The MC3407x work perfectly up to 100kHz.

An MC3407x opamp will work perfectly in your circuit with a single polarity supply.

 

Yeah, go out and buy some MC3407x opamps, just in case you ever need a good audio amp.

 

I tested the circuit with a lousy old LM324 made by TI. I used a 33Ω load. The output slewed from 0 to 5V in 16usec, and from 5V to 0V in 16usec.
I'm not saying that all LM324s will slew this fast. I'm just sayin'.

Thanks, Ron. Yours is pretty quick.

Maybe very old opamps have been improved over the years.
But the datasheets still spec the old ones.

 

Thanks, Ron. Yours is pretty quick.

Maybe very old opamps have been improved over the years.
But the datasheets still spec the old ones.

Actually, 5V/16usec is only about 0.3V/usec, which is reasonably close to the graphs in the TI datasheet.
My point was (and still is), even if the transition times are 100usec, that is probably OK for the OP's 1ms pulse.

5v/100usec=0.05v/usec.

Still, I prefer op amps with actual specs for slew rate.

 

I have implemented 1ms 555 monoshot and cascaded it to the (Resistor ladder + Op-Amp_BJT) to form the final project.

Wow! everything is working fine as expected.

But here is one interesting factor I have noticed, without any trigger 555 monoshot outputs 10mV. Is there any noise effects?

 

I have implemented 1ms 555 monoshot and cascaded it to the (Resistor ladder + Op-Amp_BJT) to form the final project.

Wow! everything is working fine as expected.

But here is one interesting factor I have noticed, without any trigger 555 monoshot outputs 10mV. Is there any noise effects?

The datasheet for a 555 has graphs that show the typical output low voltage vs load current. It is never 0V. The output of a Cmos 555 goes very close to 0V when it has no load.

 

Here is my output for the circuit implemented using 555-LM324-2N2222 with Connection taken from 4.5V plug of the resister ladder.

Anomalies observed:

1. Even if I have implemented one Differentiator circuit, according to the manual pushing speed of the trigger switch the 1ms output duration is 'slightly' varying and some disturbances occur in the output pulse

Can I solve this by incorporating 74LS14 schmitt trigger inverters(2 Nos) in series with Microswitch.

2. Some noise like spikes are there at high level and low level of the output pulse. Is this is due to circuit or measurement setup ?

(0.5V voltage divisions from 5 to 0V are perfectly taking place with the use of resistor ladder having resistors of tolerance 0.01%)

 

What is the vertical scale, 2V/div?

Check noise with probe at 1x and at 10x with voltage at 500mV/div to see the extent of the noise while the switch is low.

Ensure the ground lead is short and connected to the probe well.

Do you have a 0.1uF cap across the supply pins on the op-amp, 555, and switch (with a 1k pullup resistor on the non-grounded switch side). The switch cap will reduce bounce and possibly noise, while the others reduce noise on the power rails.

 

It looks suspiciously like quantization noise from the ADC/DAC in the 'scope.