Function generator safety question - Page 1
Forum section: electronics / beginners

author: lkuchars
author_rank: Contributor
timestamp: November 05, 2020, 04:49:10 pm
content: Soon I'll be testing industrial servo drive and planning to buy simple function generator like this one. I was wondering if there are any big no nos regarding where you connect ground plug of output. I know that ground of OScope is directly connected with mains (usually) and without special equipment I need to be careful where I connect scope ground. What about function generators?

author: rstofer
author_rank: Super Contributor
timestamp: November 05, 2020, 04:50:53 pm
content: Should be the same thing: The shell of the BNC connector is connected to earth ground through the power cord.

author: palpurul
author_rank: Regular Contributor
timestamp: November 05, 2020, 05:37:01 pm
content: Same.

author: lkuchars
author_rank: Contributor
timestamp: November 05, 2020, 06:29:46 pm
content: Thank you for the help.

author: David Hess
author_rank: Super Contributor
timestamp: November 06, 2020, 02:44:53 am
content: Like the others said, the usual rules apply. Some function generators have galvanically isolated outputs just like some oscilloscopes have galvanically isolated inputs.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: November 06, 2020, 03:52:53 pm
content: Do you also have a picuture of the back?Some time ago I bought a similar Function Generator (JDS6600) and it's power supply was a dubious 5V adapter with a 5.5 / 2.1mm plug.I intend to throw the adapter away (I don't trust it) and replace it with a small C-core transformer I have lying around. C-core transformers have a very big separation between primary and secondary windings and have therefore excellent isolation properties and very low capacitive coupling.I also encourage you to open your function generator and have a look inside.There is plenty of space available to build a power supply into it.Another upgrade you may want to consider is to upgrade the resistors of the DAC's to hand sorted values to improve linearity.

author: lkuchars
author_rank: Contributor
timestamp: November 06, 2020, 04:24:09 pm
content: Quote from: Doctorandus_P on November 06, 2020, 03:52:53 pmThank you. I just wanted to get general feeling if that's something that I should be cautious about. I don't have any brand/model selected yet.

author: wizard69
author_rank: Super Contributor
timestamp: November 06, 2020, 08:27:36 pm
content: Quote from: lkuchars on November 06, 2020, 04:24:09 pmBeing cautious is just good practice, especially if working on older equipment. In most cases the you will have a grounded reference on modern electronics. Always read and understand a devices functionality, the manual is a good start. One thing to watch out for though is the ultra cheap equipment from China, make sure that the equipment is grounded. Also battery operated equipment can have floating references which you need to be aware of, especially if they have un-insulated BNC type connectors (or similar) or other connectors that might expose you to high voltages.So yeah being careful is important and not exposing yourself to lethal voltages should be high priority. Of course you don't want to blow up instruments or stuff you are working on either. Staying safe involves knowing your equipment and understanding the measurement you are about to make.