Power Supply Capacitors keep going up in Smoke?

[ronv]

Your right Ron. I just picked some to look at the ripple current for an idea. But having said that the data sheets for 3300 ufd. @ 50 vdc put their life in jeopardy .

 

[gary350]

My power supply now has 9 electrolitic capacitors = 20,440 uf, also six .1uf caps, two .01uf, one .001uf caps in parallel.

I have 2 choke coils 8mh on the + side of the LC coil and the other 8mh on the - side of the LC coil.

The induction heater is working better than every it heats a 3/8" steel rod to 1300 degrees in 55 seconds.

My micrometer shows the mosfet wires are .031" that = #20 wire. My amp meter shows peak current = 8.4 amps. It seems like the mosfet wires would over heat and burn off?

The 3 ounce heat sinks heat up to 120 degrees in 2 minutes so I am thinking about replacing them both with 2 CPU heat sinks with fans to keep the mosfets cool. I will need to extend the mosfet wired 1" longer I hope that is not a problem for the LC circuit?

Both of the 8mh choke coils wound with #16 enamel coated copper wire are getting hot. They warm up to 130 degrees F in 2 minutes. Not sure what to do to keep the chokes from getting so hot?

8 turns works better than 6 turns but only because I did not add more capacitors to keep the frequency at 60 KHz. Rotate the coil 90 degrees it still works perfect, excellent for heating 1.5" diameter pipe red hot. Stick the coil up the hole.


**broken link removed**

 

[Mosaic]

I once had a friend who kept upgrading his turbo charged car with various parts as he increased power. When a part broke, he would upgrade it. He didn't have the theory of it all, he was a practical sort of guy, very handy. He once tried to 'brass' braze a cracked cast iron turbo engine exhaust manifold, the braze melted right off in use!

One day I did an engine job and installed new piston rings. My friend told me to over rev the newly done engine to 'temper' the piston rings. We had a huge disagreement over this, eventually leading to my pointing out that I never broke an engine and he had 5 that he wrecked in his backyard for mechanical 'spares'. He's not a friend anymore as he took that comment personally.

The OP needs to do some reading on the theory of operations and get access to a O'scope to watch for ringing etc. if he plans to 'boost' the power of his copied induction furnace or things will break and burn.

 

[moffy]

I once had a friend who kept upgrading his turbo charged car with various parts as he increased power. When a part broke, he would upgrade it. He didn't have the theory of it all, he was a practical sort of guy, very handy. He once tried to 'brass' braze a cracked cast iron turbo engine exhaust manifold, the braze melted right off in use!

One day I did an engine job and installed new piston rings. My friend told me to over rev the newly done engine to 'temper' the piston rings. We had a huge disagreement over this, eventually leading to my pointing out that I never broke an engine and he had 5 that he wrecked in his backyard for mechanical 'spares'. He's not a friend anymore as he took that comment personally.

The OP needs to do some reading on the theory of operations and get access to a O'scope to watch for ringing etc. if he plans to 'boost' the power of his copied induction furnace or things will break and burn.

While I agree with your statements I am amazed that gary350 has progressed so far, something has to be said for perseverance. He does also listen to advice. But solid design and calculation is a much better foundation. There is only so far that certain designs can go before a major rethink is required.

 

[Mosaic]

He'll do well once he understands the issues involved

 

[moffy]

I agree. The proper design is more complex than the simple circuit implies.