Author Topic: Uses for the Square wave fixed frequency output on DMMs?  (Read 2487 times)

0 Members and 1 Guest are viewing this topic.

Offline kalel

  • Frequent Contributor
  • **
  • Posts: 880
  • Country: 00
Uses for the Square wave fixed frequency output on DMMs?
« on: July 02, 2017, 10:59:54 am »
I asked previously about some uses of the manual hold button.

This time, I would like to ask about the fixed frequency output "square wave" function of multimeters. Usually it's a fixed 50 Hz with 0.5 duty cycle. At least a few meters offer it, starting from the famous DT series.
What could this function be used for? In case it's only available on cheap multimeters, I would assume it's not designed especially as a kind of test signal for a scope, plus it likely wouldn't make a good/accurate one anyway.
I'm not sure if there's enough power to test with any LEDs or beepers. Maybe for testing simple transistor amplification circuits? If you only have a transistor, an LED and no other source for the gate signal, perhaps it makes sense. Maybe there's no specific intention, but I imagine this could have more uses than the manual hold button.
 

Offline alm

  • Super Contributor
  • ***
  • Posts: 1291
  • Country: 00
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #1 on: July 02, 2017, 11:20:57 am »
Given that it is only found on cheap meters, unlike the hold button, I am not so sure about the more useful part :P. I can only see it being useful if you have some other meter or scope to observe the output of your circuit.
 
The following users thanked this post: kalel

Offline WhichEnt2

  • Regular Contributor
  • *
  • Posts: 98
  • Country: ru
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #2 on: July 02, 2017, 11:28:44 am »
I heard once that it function being used for checking the segments on the liquid crystal displays or something.
Short pieces, high value, small period, huge amount, long delay.
 
The following users thanked this post: kalel

Offline bjcuizon

  • Frequent Contributor
  • **
  • Posts: 284
  • Country: nz
  • RF and Analog Electronics Enthusiast
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #3 on: July 03, 2017, 07:16:31 am »
Maybe it is for testing some kind of audio device. :-// I tried using it to test some audio amp and it outputs something like the 50Hz mains hum (like when you plug in a guitar cable for example.)
Don't mess with an Electronics Engineer, it Megahertz!
 
The following users thanked this post: kalel

Offline BU508A

  • Super Contributor
  • ***
  • Posts: 1748
  • Country: de
  • Per aspera ad astra
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #4 on: July 03, 2017, 08:27:32 am »
Given that it is only found on cheap meters, unlike the hold button, I am not so sure about the more useful part :P. I can only see it being useful if you have some other meter or scope to observe the output of your circuit.

I would not consider the Agilent U1252B as a "cheap meter".

“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 
The following users thanked this post: kalel

Offline Electro Detective

  • Super Contributor
  • ***
  • Posts: 2713
  • Country: au
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #5 on: July 03, 2017, 08:40:58 am »
Whatever priced meter it's on, it would be handy as a go / no-go speaker tester, or certain mf types of capacitors ?  :-//
« Last Edit: July 03, 2017, 08:43:45 am by Electro Detective »
 
The following users thanked this post: kalel

Offline jpb

  • Super Contributor
  • ***
  • Posts: 1711
  • Country: gb
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #6 on: July 03, 2017, 09:09:06 am »


I would not consider the Agilent U1252B as a "cheap meter".

It is not, but it does not have a fixed frequency, fixed duty cycle square wave output. Its square wave output is variable in frequency and duty cycle so could be used with pwm circuits.

Some cheap meters, apparently, have just one fixed frequency 50% duty cycle output which is rather less useful and I suspect is more a marketing thing so it looks like they have the same as more expensive meters.
 
The following users thanked this post: Electro Detective

Online Fungus

  • Super Contributor
  • ***
  • Posts: 10821
  • Country: 00
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #7 on: July 03, 2017, 10:23:25 am »
I would not consider the Agilent U1252B as a "cheap meter".
It is not, but it does not have a fixed frequency, fixed duty cycle square wave output. Its square wave output is variable in frequency and duty cycle so could be used with pwm circuits.

Some cheap meters, apparently, have just one fixed frequency 50% duty cycle output which is rather less useful and I suspect is more a marketing thing so it looks like they have the same as more expensive meters.

I suspect the OP is talking about the new AN8008, which isn't fixed frequency.
 
The following users thanked this post: kalel

Offline kalel

  • Frequent Contributor
  • **
  • Posts: 880
  • Country: 00
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #8 on: July 03, 2017, 11:22:39 am »
I would not consider the Agilent U1252B as a "cheap meter".
It is not, but it does not have a fixed frequency, fixed duty cycle square wave output. Its square wave output is variable in frequency and duty cycle so could be used with pwm circuits.

Some cheap meters, apparently, have just one fixed frequency 50% duty cycle output which is rather less useful and I suspect is more a marketing thing so it looks like they have the same as more expensive meters.

I suspect the OP is talking about the new AN8008, which isn't fixed frequency.

Actually I was talking about the fixed frequency ones (I have a DT with that function, never found much use for it), but as for AN8008, it's a shame it doesn't offer a temperature setting like AN8002.
 

Online Fungus

  • Super Contributor
  • ***
  • Posts: 10821
  • Country: 00
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #9 on: July 03, 2017, 11:29:10 am »
as for AN8008, it's a shame it doesn't offer a temperature setting like AN8002.

I think it can be hacked to enable it, but at that price you can have both!

 
The following users thanked this post: kalel

Online Shock

  • Super Contributor
  • ***
  • Posts: 3274
  • Country: au
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #10 on: July 04, 2017, 04:51:55 am »
Keysight U1252B User’s and Service Guide: Square Wave Output
Quote
The square wave output function can be used to generate a PWM (pulse width modulation) output or provide a synchronous clock source (baud rate generator). You can also use this function to check and calibrate flow-meter displays, counters, tachometers, oscilloscopes, frequency converters, frequency transmitters, and other frequency input devices.

On this specific meter you can adjust the frequency, duty cycle and pulse width.
Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 87V, 117, 27/FM       >>> WANTED STUFF <<<
Oszilloskopen: Lecroy 9314, Phillips PM3065, Tektronix 2215a, 314
 

Offline Crumble

  • Regular Contributor
  • *
  • Posts: 96
Re: Uses for the Square wave fixed frequency output on DMMs?
« Reply #11 on: July 17, 2017, 09:22:40 pm »
as for AN8008, it's a shame it doesn't offer a temperature setting like AN8002.
I think it can be hacked to enable it, but at that price you can have both!
I have an AN8002, but I usually use a generic TM-902C temperature meter for measuring temperature. They are just a few $, and they liberate a multimeter for the electric work. I'd recommend to get one of those. :-+
 
The following users thanked this post: kalel


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf