Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

+/-40V SMPS virtual ground

Status
Not open for further replies.

j0no89

New Member
Hey, I am currently designing a switchmode power supply with +/-40V @ 2A based on the TOP258YN. So, getting on with my question, in the reference designs for a split rail supply they use a transformer with a centre-tapped secondary winding, but the only transformer i can find on digi-key (where im ordering all my other parts) that is capable of putting out this much power and has an appropriate turns ratio has no centre tap on the secondary (Wurth Electronics 750311269).

**broken link removed**

To overcome this problem i found a 'virtual ground' circuit on https://tangentsoft.net/elec/vgrounds.html. So, my question is, what is the actual potential of the common rail in this virtual ground circuit w.r.t the mains input earth. I dont really understand how the virtual ground works so im not sure if it is a true split rail supply or is it just creating a reference halfway between the 2 rails and saying that the 2 rails are +/-40V w.r.t that reference (which would be 40V w.r.t earth). Mainly i just want to know if this common rail is safe to connect to the mains earth reference.

**broken link removed**

Thanks in advance for any help, if its unclear what im asking just let me know and ill try and be more clear!
 
Get a proper transformer, that's the only way to do it correctly - not to mention cheaply and reliably.

Or you could simple design your amp to use a single supply?.
 
You will probably have to go custom or wind your own. I did, once, wind a small toroid power transformer, but don't know how to design one.

These guys seem user friendly for custom designs: **broken link removed**

I did have a custom power transformer designed for an audio amp once in the 80's for about $130 USD. 4 x 35 VAC at 3A, about 400 VA
 
If you have the transformer from Wurth Electronics, check to see if the secondary is on the outside. If so unwind and rewind the secondary.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top