EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: mendip_discovery on August 11, 2023, 05:10:42 pm
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I am looking for a portable bit of test gear that is sensibly priced and has a PWM (Power Wave Modulation) output.
I have a random eBay item that does it but it's an open circuit board and I could do with something that the customer won't start asking questions of. But at the same time I doubt I could get a Fluke Loop calibrator past the boss.
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I am looking for a portable bit of test gear that is sensibly priced and has a PWM (Power Wave Modulation) output.
I have a random eBay item that does it but it's an open circuit board and I could do with something that the customer won't start asking questions of. But at the same time I doubt I could get a Fluke Loop calibrator past the boss.
Not Pulse Width Modulation ? :-//
What's the difference if you don't mind ?
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I am looking for a portable bit of test gear that is sensibly priced and has a PWM (Power Wave Modulation) output.
I don't think that's what PWM stands for.
I have a random eBay item that does it but it's an open circuit board and I could do with something that the customer won't start asking questions of. But at the same time I doubt I could get a Fluke Loop calibrator past the boss.
Put it in a box?
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Better detail yorurequirements a bit more. Plain PWM? Closed loop? Modulation input?...
This could get as basic as a 555 with a battery, to lots of $$.
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Better detail yorurequirements a bit more. Plain PWM? Closed loop? Modulation input?...
Output frequency, precision, voltage, current...?
This could get as basic as a 555 with a battery, to lots of $$.
Or an Arduino.
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I am looking for a portable bit of test gear that is sensibly priced and has a PWM (Power Wave Modulation) output.
I have a random eBay item that does it but it's an open circuit board and I could do with something that the customer won't start asking questions of. But at the same time I doubt I could get a Fluke Loop calibrator past the boss.
Not Pulse Width Modulation ? :-//
What's the difference if you don't mind ?
You are right, pulse width modulation. Not sure where I got power wave modulation from.
I have to test a machine that uses PWM as part of its tests. It generates and measures so I am looking for a neat way to do this. It 100 Hz at 50% so nothing special. The customer has a Fluke Loop calibrator but that is >£1000 which just for me to use on 4 machines is a little pricey. We are looking to get a handheld multimeter to do the measurement side of it, Fluke 87 or 287 depending on what we can find, that will at least have a use generally around the lab.
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So the approach would be to manually verify the machine operation when setting different duty cycles, right?
These would do it for 5 bucks:
https://www.aliexpress.com/item/1005002771032403.html (https://www.aliexpress.com/item/1005002771032403.html)
https://www.aliexpress.com/item/1005004255904120.html (https://www.aliexpress.com/item/1005004255904120.html)
https://www.aliexpress.com/item/1005003352241302.html (https://www.aliexpress.com/item/1005003352241302.html)
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If all you need is 50% at 100 Hz, Paisley's compilation of circuits shows a simple way to get that with a 555: http://www.circuitous.ca/LM555.html#23 (http://www.circuitous.ca/LM555.html#23)
Since the 50% duty cycle is obtained by logic, my understanding is that it is relatively accurate; whereas, the frequency that is dependent on an RC circuit is not so accurate.
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It 100 Hz at 50% so nothing special.
It's not entirely clear to me what you need.
If you just want to generate a square wave at 100Hz, maybe your cheap multimeter will do?
An8008 (https://www.aliexpress.com/item/1005005196905116.html) for example can do that quite accurately.
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Build (https://www.circuitbasics.com/pulse-width-modulation/) your own and put it in a box.
Or if you want something fancier, would a fnirsi DSO-TC3 satisfy?
Very portable, and has a signal generator scope and component tester
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Build (https://www.circuitbasics.com/pulse-width-modulation/) your own and put it in a box.
Or if you want something fancier, would a fnirsi DSO-TC3 satisfy?
Very portable, and has a signal generator scope and component tester
I think the DSO-TC3 should do it fine. It's one of them jobs that if I turn up with something home made that I know I will get questions over it. It's a job I have ended up taking on becuase a bunch of cowboys decided they didn't want the job anymore, supposedly they also make multimeters but have to rebrand every few decades. As our firm is local to the job and my boss loves money I get volunteered to do the work, but as cheaply as possible.
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There's also these signal generators... search aliexpress.com for "SG-003A Signal Generator".
https://a.aliexpress.com/_mO0Ng5s