Does this signal generator have an isolated output?

[treez]

Does this signal generator have an isolated output?

GW INSTEK GFG-8015G
**broken link removed**

 

[rfredel]

Hello treez,

download the user manual. Look for the circuit diagram.

It is no clear, if the generator has an isolated output. I think, that it is dependent of your power line. If you don't have a special ground wire, it be be isolated else the output is grounded.

Regards

Rainer

 

[treez]

..theres no cct diagram.

So do you think its ok if i snip the earth out of my three pin plug?

 

[rfredel]

Hello treez,

that you must know by yourself. It's a problem of safety. Here in Germany it's prohibited. Here you have to use a isolating transformer.

Look at the User manual page 46. In the middle of the page you find S502. That is the attenuator switch. The right conntact is the output. In the diagram it looks like an connection to ground, but it's the output.

Follow the ground symbol. You see, that the centre tap of the secundary winding and the core of the transformer are connected. It's not shown, that you have a connectio to Line ground. I think it dependent from the law of the country, where the generator is use.

In my workshop I have a isolation transformer, where my multimeters, generators and oscilloskop are connected. So I have an isolation to the line. Also I have to use an isolation transformer for repair.

I hope this helps.

Regards

Rainer

 

[treez]

Thanks, i see the cct diagram on page 46, but i see no earth ground connection....i see only two wires from the plug, neutral and live......there is definetely no earth ground connection......the ground symbol you speak of is just the secondary side common.

It's a problem of safety

...not in France it isn't........................they only have two pin plugs and never connection of earth ground to product.

In electronics test or repair everybody uses an isolation transformer, i accept that.

I used to work on flat screen television power supply test and development.....................we always worked through isolation transformer like you say.....

-when new engineer came to work, they would secretly snip off the 1 MegOhm resistors that were connected between primary and secondary of the smps..(without him seeing this) ........then the engineer would touch against the secondary, thinking it safe because he had the isolation transformer in the input....but ZAPP!!!....he would get a nasty capacitive shock, because without the 1 Meg resistor, the secondary would creep up and float to a high voltage.......charging to this high voltage via the interwinding capacitance of the isolation transformer..........................so i advise, that isolation transformer is not always as helpful as we sometimes think.....especially old ones that have worn out insulation...............................

...and yes, when i started work there i had my fair share of ZAPPS!!...............................then i sussed it out, noticing the snipped away 1 meg resistors.................often it happening when i was in the canteen for tea break.