I am thinking that 8 to ten volts would be reasonable.That puts the transistor current is developing 5 volts across 400 ohms

 

T

I am thinking that 8 to ten volts would be reasonable.That puts the transistor current is developing 5 volts across 400 ohms

Thanks MisterBill2. So you think that this circuit would work for say up to perhaps 30MHz?

 

T

Thanks MisterBill2. So you think that this circuit would work for say up to perhaps 30MHz?

With an adequate input signal it should. My experience with frequency counters is that with some of them, sensitivity does vary with the frequency.

 

This was a big waste of time!

 

This was a big waste of time!

That is what you get here!

 

This was a big waste of time!

Of course it was. The problem was badly specified at the beginning.

 

That is what you get here!

Is that coming from your vast three months of experience?

Look at the schematic and text in post #1, and then look at the requirements list in post #16. I completely agree that this thread has been a waste of time, but probably not in the way you mean.

ak

 

And the problem is, TS needs to understand what is a digital signal. Digital signals are still analog.

You don't need an analog to digital converter. You simply need to define a threshold voltage above which you define it as 1 and below it is 0. Every "digital" input circuit already does that. Every digital circuit is a 1-bit analog-to-digital converter.

 

And, all 1-bit analog-to-digital converters are equal but some are more equal than others, depending on the analog signal.

 

That is what you get here!

Forums are a two-way street. Tell us all about your particular contributions.

 

AN LM311 comparator is able to be much faster.

 

AN LM311 comparator is able to be much faster.

It is also older and crankier than modern devices. It is not suitable for amateur designers.

 

and while LM311 is faster than LM339, still neither will do 60MHz. maybe 5MHz at best and signal will be distorted. why not use something better and simpler like SN74LVC1G17-Q1?