Create a Square Wave with Op Amp: Simple Circuit Design

[forex10]

Hello,
I would like to produce a waveform like the one below. A square wave, then a 0 volt pause, then resume the square wave. I suspect there are a dozen ways to do this using an op amp & other circuit components but have not been able to create the circuit. Also - I have a function generator that could produce a square wave to start with.

(Please excuse the quality of this drawing - I have not used practiced online drawing in a while.)

 

[Hesch]

A binary counter setting the address of a PROM ( Programmable Read Only Memory ).
So when the counter is running, it will address different cells in the PROM, which in turn will set the output high/low according to the cells being programmed '1' or '0'.

 

[Khashishi]

You can "and" the clock signal with a gate signal. It's not clear from your question if you want to zero the output for a specific number of cycles or via some externally generated length of time. You might be able to use a binary counter as a clock frequency divider, and use the output as a gate signal.

 

[berkeman]

Hello,
I would like to produce a waveform like the one below. A square wave, then a 0 volt pause, then resume the square wave. I suspect there are a dozen ways to do this using an op amp & other circuit components but have not been able to create the circuit. Also - I have a function generator that could produce a square wave to start with.

(Please excuse the quality of this drawing - I have not used practiced online drawing in a while.)

View attachment 94059

I didn't open your attached *.ZIP file, because ZIP files can pose security problems. But, the title of your ZIP file contains the word "Aurdino" (maybe a misspelling of Arduino), so why don't you just use a microcontroller like an Arduino to generate the waveform?

 

[forex10]

I tried using the arduino program & it produced a rather poor square wave, while my function generator produced an excellent wave. Khash I want to try both of what you recommended for the 0 volt portion. There is a lot to experiment with here once I get this part accomplished. Thanks for the responses.

JoeL

 

[meBigGuy]

Some function generators have repetitive pulse bursting. Some function generators have pulse gates.
Some function generators can create a pulse burst when triggered.

Several things are not clear about your requirements.

1. What frequency or frequencies? Fixed or variable?
2. What load do you need to drive?
3. What voltages?
4. What period do you want to be off? on? Are either or both off time and on time programmable?
5. Do the pulses all need to be "clean"? That is, no shortened pulses?
6. What controls the off period? The on period?

There are quite a few ways to attack the problem, depending on your real control and waveform requirements.
For example, a pair of loadable binary counters can easily create programmable off and on times synchronized to the pulse train to gate the pulses.

Or, you can build a 555 gated astable if it suits your needs. Again, depends on what you REALLY need.
http://en.f-alpha.net/electronics/integrated-circuits/timer-555/go-on/experiment-16-gated-amv/
http://en.f-alpha.net/electronics/b...go-on/experiment-20-gated-amv-with-timer-555/

 

[forex10]

I accomplished creating this circuit using resistors & a branch wire. I still get some ac leakage in the central (DC) portion but believe this could be alleviated by a filter. Just thought I would provide an update.