Building a passive energizer from scratch --- to ground or float the bias supply?

[bobkatz]

For the bias voltage, I will be using a DC power supply I'm getting from Ebay:

Bertan PMT-10C/N -1 kV 4mA Adjustable High Voltage DC Power Supply. Even though this supply takes in a DC input, the spec sheet says: "These fully enclosed modules are specifically designed with proprietary linear power conversion techniques to provide exceptionally low ripple and noise"

Not sure how they can get a regulated high voltage from +24 VDC using "linear techniques", but  in without using a switcher, but anyway, my question is: Is it necessary to ground one side of the bias supply? That is, connect it to chassis, U ground and audio ground?  Is it necessary or useful for one side of the bias supply to be connected to the same ground as the source audio power?  What do you think ?

Also, I should measure and see if the Bertan's output is galvanically isolated from its input and maybe ask the company if it's even ok to ground one terminal of its output. 

 

[bobkatz]

Well, I found an app note from Spellman High Voltage, that makes the Bertan supply. Looks like Grounding is a VERY Good idea:

How should I ground your supply? 

Grounding is critical to proper power supply operation. The ground connection establishes a known reference potential that becomes a baseline for all other measurements. It is important that grounds in a system are low impedance, and are connected in such a way that if currents flow through ground conductors they do not create voltage level changes from one part of the system to another. The best way to minimize the possibility of creating voltage differences in your system grounding is to use ground planes via chassis and frame connections. Since the source of the high voltage current is the power supply, it is recommended that it be the tie point for system grounds to other external devices. 

The rear panel of the power supply should be connected to this system ground in the most direct, stout manner possible, using the heaviest gauge wire available, connected in a secure and durable manner. This ties the chassis of the supply to a known reference potential. It is important to understand most damage to HV power supplies occur during load arcing events. Arcing produces very high transient currents that can damage power supply control circuitry (and other system circuitry) if grounding is not done properly. The product manual provides more detailed information regarding grounding requirements. If you have any additional questions, please contact the Sales Department. 

[kevin gilmore]

first make sure the bertan is positive voltage output!!!!.  because they make both.

edit, because its a 24vdc input. the chassis of the power supply needs to be wired to ac input ground.

make sure the bertan ground goes the center tap of the transformers.

Edited July 30, 2023 by kevin gilmore

[bobkatz]

6 hours ago, kevin gilmore said:

first make sure the bertan is positive voltage output!!!!.  because they make both.

edit, because its a 24vdc input. the chassis of the power supply needs to be wired to ac input ground.

make sure the bertan ground goes the center tap of the transformers.

Thanks, Kevin. Yes, it is positive voltage input. It's hard to tell, but I think the output polarity follows the input polarity. It's good to hear your advice and I'm very glad that it matches what I received from another expert. 🙂 I will ground the center taps to chassis AND to audio input ground.  Please see the thread on the Topping amp for what I discovered about its onboard DC-DC converter.