Author Topic: FY3200S Easy fix to AC leakage current problem.  (Read 4573 times)

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Offline InsatmanTopic starter

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FY3200S Easy fix to AC leakage current problem.
« on: May 19, 2017, 01:58:59 am »
I own the FeelTech FY3200S function generator.  Recently I watched a YouTube video where a man in England modified his to stop leakage current from the AC mains to "ground", ie the BNC outer.  He did this by replacing the existing switching supply with a linear setup.  It was quite involved and he optically isolated the USB port as well.   Sadly I don't have a link to this video.   

I wanted to isolate my unit for both safety and ground noise problems but decided to take the easy way out.   See photo.

The 220VAC isolation transformer is from Digikey and cost's about $17.   There may be other cheaper transformers out there.  I chose this one because it's low profile and I've used this series before with great results.   

Dave
Retired Pulsed Power Engineer/Physicist...now I just dabble in electronics
 

Offline HoracioDos

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Re: FY3200S Easy fix to AC leakage current problem.
« Reply #1 on: May 19, 2017, 11:44:13 am »
I own the FeelTech FY3200S function generator.  Recently I watched a YouTube video where a man in England modified his to stop leakage current from the AC mains to "ground", ie the BNC outer.  He did this by replacing the existing switching supply with a linear setup.  It was quite involved and he optically isolated the USB port as well.   Sadly I don't have a link to this video.   

I wanted to isolate my unit for both safety and ground noise problems but decided to take the easy way out.   See photo.

The 220VAC isolation transformer is from Digikey and cost's about $17.   There may be other cheaper transformers out there.  I chose this one because it's low profile and I've used this series before with great results.   

Dave

You will find everything you need here.
https://www.eevblog.com/forum/testgear/feeltech-fy3224s-24mhz-2-channel-dds-aw-function-signal-generator/

I think that there's no need for another thread about this topic.

 
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Offline qq354813374

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Re: FY3200S Easy fix to AC leakage current problem.
« Reply #2 on: June 23, 2017, 09:34:37 am »
First of all, in the absence of the introduction of the ground wire of the two-wire plug of the switching power supply system will have such a situation.
In order to suppress common mode interference, the switching power supply in the design, the "safety capacitor" will be between the "LG / NG" (safety capacitor is used for such occasions, even if the capacitor fails, will not lead to electric shock,  so the secondary side of the switching power supply "ground" is equivalent to the midpoint of the AC voltage, so you measured 110V voltage. But this does not mean there will be security risks, after all, the capacitance capacity of only 1000pf.
If you are still worried about its leakage, then the correct way is to measure its DC leakage resistance, the use of insulation tester is the most effective way
 

Offline tankcreature

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Re: FY3200S Easy fix to AC leakage current problem.
« Reply #3 on: September 24, 2019, 02:29:02 pm »
How did you wire the transformer? I have one of these but I am not sure how to wire it for 110v.
 


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