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.

Power supply question

Status
Not open for further replies.

gary350

Well-Known Member
I did a thread about 4 month ago maybe longer on this circuit is there a way for me to find all my past threads, other forums have that option? I looked way back never found it.

I put my circuit back together today with new improvements. I replaced the Chinese bridge rectifiers that kept self destructing at 15 amps with 40 year old bridge rectifiers that are not Chinese.

I built a dedicated power supply for each circuit. The gate circuit has a 12 VDC power supply. As I added capacitors 1 by 1 voltage kept going up until I added the 5th cap then voltage dropped. 4 caps are giving me 11.94 VDC. When I was in college we used a scope to added enough caps to get flat line DC. I wonder if 4 caps 3300uf each is giving me flat line 12VDC at 1 amp? This is working good, big improvement over what I had before.

The other power works the same 12 caps 3300 uf gives me 21 VDC. If I add or remove caps voltage drops. Adding more caps only drops .01 volts.

The circuit is working good like before 21 VDC 36 amps on the meters with a 3/8" rod in the work coil. After the rods turns red hot amps drop to about 7 amps. With no rod at all current is 5 amps. Mosfets are not even getting warm at 36 amps and I have no cooling fan. We played for 10 minutes heating all kinds of things red hot heat sinks are not noticeable warmer. Frequency is 88KHz with no load, 82KHz with 3/8" load, then 84KHz with red hot load. I am putting water on work coil to keep it cool.

Next I want to see what I can learn by changing the circuit so the work coil has no center tap.

100_1471_zpsktop2jxr.jpg
 
Last edited:
is there a way for me to find all my past threads
Click on your user name button at the top of the page, then select 'Your content'.
 
The center tap offers the advantage of full wave source current with only a half bridge

Whereas a full bridge offers voltage doubling (albeit twice the conduction losses) over twice the coil length or impedance for V^2/Z or 4/2= for twice the output power minus slight additional FET loss.
 
Last edited:
Click on your user name button at the top of the page, then select 'Your content'.

I don't see a user name button. If I click my user name it opens with information's like, town I live in, been a member since 2005, replied to 285 posts. I don't see anything about Your Content.
 
The circuit is working good like before 21 VDC 36 amps on the meters with a 3/8" rod in the work coil. After the rods turns red hot amps drop to about 7 amps. With no rod at all current is 5 amps.

The amps drop is probably due to the heat of the steel. When it reaches it's curie point (curie temperature), it is no longer magnetic.
 
I don't see anything about Your Content.
Hover over your user name. 'Your content' is in the right-hand column of the drop-down box.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top