I am about to use the handy calculator here and build a few different frequencies.
Is there a way to measure the output without a scope ?
Would a zVOM meter on the AC setting show anything helpful ?

Thanks

 

Do you have a datasheet for the meter, or a link to a product page, or any information? Some digital multimeters can measure frequency, but most cannot.

To verify that a circuit *probably* is working, one thing you can do is drive an LED with the output, and increase the timing capacitor to slow down the frequency until you can see the LED blink.

ak

 

You could use a simple diode charge pump to get some idea of the frequency. If you can cope with the maths this is a good description: http://www.inictel-uni.edu.pe/sites...s/04/diode_charge_pump_am-fm_demodulators.pdf

 

Only way is to use a Frequency counter, or a dvm with that function.

 

Hmmm, don't know if its possible but does that mean that if I had started with a pulsating DC square wave,, smoothed it out until it looked like a sine wave, although it would have no negative portion (don't know if I said that correctly), but would the VOM still not be able to measure it as AC ?

 

If there is variation of any significant kind in the waveform (sine, square, triangle, saw, whatever), then a meter with a frequency measuring function (you still have not told us about yours) will measure it. However, if the signal is something other than a sine wave, the measurement will be incorrect.

ak

 

Hooray, my meter does have a Hz function.
Oh, oh. So even though it says nn hz, it might not be correct.
It got the wall voltage accurately.

 

I edited post #6 to remove the bad part. The AC voltage function reads incorrectly if the signal is not a sine wave. The frequency function should be accurate as long as the signal is not a very narrow pulse.

ak

 

I edited post #6 to remove the bad part. The AC voltage function reads incorrectly if the signal is not a sine wave. The frequency function should be accurate as long as the signal is not a very narrow pulse.

ak

The frequency measurement function on multimeters usually has a fairly low maximum frequency, perhaps only 1kHz - 10kHz. Check the spec for your meter.

 

My Fluke multimeter can measure frequencies pretty darn high but sometimes I must measure the frequency of a sound like the RPM of a motor or the pitch of a person singing very high. Instead of setting up a microphone and preamp I use my hearing and an accurate signal on my pc from Audacity program and adjust it to the same frequency that I am measuring.

 

I am about to use the handy calculator here and build a few different frequencies.
Is there a way to measure the output without a scope ?

What range of frequency are you considering?

1. You could use counters to reduce the frequency to something visible with an LED.
2. You could use a frequency counter.
3. You could build your own counter and let it count for a second. I did this a couple decades ago using two MC14553 3 digit counters when I didn't have a scope or a frequency counter.
4. You could build a frequency to voltage converter.

 

Only way is to use a Frequency counter, or a dvm with that function.

A counter is likely to be more accurate than most scopes (analogue ones anyway) but I'm not sure how far I'd trust the added feature type on a DMM.

 

The frequency measurement function on multimeters usually has a fairly low maximum frequency, perhaps only 1kHz - 10kHz. Check the spec for your meter.

Manual says 10Hz to 10kHz

 

Manual says 10Hz to 10kHz

So as long as your '555 is running in that range then the multimeter is good for the job.

 

A counter is likely to be more accurate than most scopes (analogue ones anyway) but I'm not sure how far I'd trust the added feature type on a DMM.

Which raises the question of how much accuracy is required. If the experiment is just to get familiar with 555s and establish that they behave as intended, the frequency meter can have the same loose tolerances as the caps will probably have anyway (5, 10, maybe 20%)

 

For lower frequencies, there are scopes that cost next to nothing.


There is also software out there for your audio board though you risk damaging your audio input.