Frequency meter

I need a frequency meter that can do the following

Be able to hook directly to 0 to 120 VAC
Able to measure from 0 to 120 Hz.

Here are two applications
recently trouble shot a home generator 4000 W 120/240 single phase. Freq meter would have been nice but used tach instead. Adjusted governor to better control engine speed.

Am setting up what may be a demonstration rig for variable AC drive. Will consist of motor (variable speed probably DC cause I have one) driving an automotive alternator modified to manually control excitation. Also took out rectifiers and brought out 3 phase. Alternator power will feed to either
A -- lite bulbs to demonstrate 3 phase by slowing alternator down to say one half Hz so that the waveform can be visualized on 3 lite bulbs. Got idea from synch lamps on switchgear - works well. Have done with VFD and 3 lite bulbs works quite well.
B -- another automotive alternator again with manual excitation control and with rectifiers removed. Will be used as synchronous motor.

Because this will be in a class setting an analog meter may be better because you can see oscillations in the meter needle.

Not sure if all this will really work so want to keep cost low AND just got my second social security check. So am watching budget pretty tightly. Lets out Fluke VOM which would be NICE.

Budget can probably handle $50 or so.

Thanks for help
Dan Bentler

To answer your question 1

I believe most good multimeters have a Hz setting available that would handle your voltage, I know most of the Fluke meters have that option.

Dial Hz meters are probably better sourced from electrical suppliers who should have a range of meters , what I have seen on Generators often work on a bar the acts as a tuning forkond vibrates one segment at the frequency found.

Transformer to drop ac to a few volts. F to V IC. Analog meter.

He waits 12 hours for a reply then gets 2 in a minute

keithkyll said:

Transformer to drop ac to a few volts. F to V IC. Analog meter.

Click to expand...

OK any suggestions for who makes a F to V that you have used and trust?

Will have to study and evaluate to determine if will meet my needs and wants.

Dan Bentler

This is not as simple as I thought.
Panel instruments range 45 to 75

Fluke has no options - even DMMs respond no lower than 15 Hz they say.
Seems bottom end of almost anything for this application is 15 Hz.

Have found one unit but oh boy does it look pricy.
http://www.ectron.com/frequency.php

Am checking with local instrument outfit Branom - in Seattle.

IF nothing else works out can always go the proximity sensor or encoder and convert pulses to frequency - just a little measuring and math.

Hmmm maybe should make this learning opportunity - never worked with encoder.

thanks for ideas and help
Merry Christmas to all of us

Dan Bentler

This may work with the encoder:
http://eshop.phoenixcontact.de/phoe...=2814605&parentUID=852472996&reloadFrame=true

Should run you about $400.00

I have never used one so you'll need to read the data sheet and manual to see if it fits in your application

Since it looks like the budget is blown, I would suggest this one for $285:

http://www.wici.com/technical/manuals/wici_pdf/cat_pdf_files/MM1700_Catalog_Page.pdf

I have used these and they are very rugged an reliable...the low end of the range is 10Hz.

They also have this one which you order with whatever range you want ($250):

http://www.wici.com/technical/manuals/wici_pdf/cat_pdf_files/TW850X_Catalog_Page.pdf

Here is a candidate for you. It can handle up to 150 volts for its input.
http://www.api-usa.com/pdf/api/api_7010g.pdf
You can get one from your local Branom rep.
We are using one of API's frequency to dual alarm trip units as a limit switch. It has worked well for >4 years now.

Gentlemen

Thank you all for the help. I believe I have enough options to look at so let us close this out and save you some work. Will advise on how I make out.

Dan Bentler