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Full-wave rectifier Smoking Issue

Bridge Rectifier model: KBP5010
Microwave Oven Transformer rewired to put out 6VAC

Okay, this rectifier is ratted at 1000V 50A and I'm running After rectifying and load 4.4V and between 10 and 15 Amps, but within a minute the rectifier will start smoking, if I am not careful this will be the third one I've been through.

I reapplied the thermal paste hoping there was too much, no luck.

The transformer is directly into the AC poles of the rectifier

A 30A fuse on Positive Pole

I have a 2200uF 50V Capacitor between the Positive and Negative

Then from there I'm going into an HHO cell.

I took video of this and uploaded it to YouTube if it helps you to see what I'm talking about

Also hand drew a small diagram with mspaint I'm attaching

YouTube video UUfTYxLaJ1I
URL




Thanks in advance,

Brian T Hoover


P.S. If you need more information I will do my best to supply it.
 

Attachments

  • Circuit.bmp
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(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
To keep it relatively simple, you need a series memristor to reduce RF heating from the inductively coupled plasma discharge emanating from catalysed HHO re-integration on the Brown's electrode(s).
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
This is the first post on two forums that makes any sense.

Clearly I've been outclassed elsewhere.

I suspect that you need a larger heatsink. Either that or your voltage and/or current measurements are not accurate.

Will you eventually burn the HHO to generate power to create more HHO?
 

davenn

Moderator
firstly measure your DC current

secondly once the DC current is known replace the 30A fuse with something more appropriate say 2-3 amps higher than the DC current

3rdly as Steve suggested, you heatsink is way too small if you are drawing anything over ~5 Amps

Dave
 
Clearly I've been outclassed elsewhere.

I suspect that you need a larger heatsink. Either that or your voltage and/or current measurements are not accurate.

Will you eventually burn the HHO to generate power to create more HHO?

Only person to mention electrical feedback :)

My voltage is right Amps may not be, I have no way to measure the Amps at that low of a voltage, my gauge has a minimum of 8V max of 48V 100A, I used Ohms law to estimate it:

300W 10V 30A = 1/3 Ohm (was measured)
58W 4.4V 13.2A = 1/3 Ohm (calculated/estimated)

I'm going to try the same trick as a motor controlled by PWM and try to prevent back-surge Only logical guess, other than just using 11.5-13.3V input, but I cannot run it long enough at one time to condition the plates.


Currently with the HHO I'm running a push mower, soon I hope to have it in my car and (theoretically) increase mileage.
 

davenn

Moderator
, I have no way to measure the Amps at that low of a voltage,

Yes you do ... low voltage has nothing to do with not making a current reading

for a start you need to estimate the current by dropping that 30 Amp fuse to 10A
and see if it blows
if it does, try a 15A fuse, if it doesn't blow then you have narrowed down the current to between 10 and 15 Amps .... easy :)

IF a 10 A fuse doesn't blow, then put you multimeter to DC10A and put it series with the positive lead from the rectifier to the cell and measure the current

cheers
Dave
 
Yes you do ... low voltage has nothing to do with not making a current reading

for a start you need to estimate the current by dropping that 30 Amp fuse to 10A
and see if it blows
if it does, try a 15A fuse, if it doesn't blow then you have narrowed down the current to between 10 and 15 Amps .... easy :)

IF a 10 A fuse doesn't blow, then put you multimeter to DC10A and put it series with the positive lead from the rectifier to the cell and measure the current

cheers
Dave

I guess let me rephrase I don't have a way to do that (currently) only other fuse I have on hand is 1.5amp

Until then I got two heatsinks I can put together into one to try to reduce heat

But either way I cannot see how it can be smoking when I can still hold it tightly in my hand, without discomfort

P.S. I just read your first post lol you posted after I started my last reply and once I submitted I had to leave
 
The bridge will drop 1.1V, at 15A this is 16.5W heat. The Rth value of the heat sink is relative high, so you'll get a high temp fast. Let's be kind and say it is 10 K/W, this is 165C above ambient, at the heatsink. At the silicon it's much higher, around 200C and ready for smoking.

The drop is 1.1V per leg, I don't know if you need to double that for the circuit, but thats even worse.
 
The drop is 1.1V per leg, I don't know if you need to double that for the circuit, but thats even worse.

The bridge voltage drop will be 2.2V since two diodes are passing the current at any one time.

Edit
The bridge must be fitted firmly to the heat sink. You need maximum area and minimum thickness of heat sink compound.
 
Last edited:
The irony is about to make my head explode.
You do realize that Steve's post was a joke, right?

Bob

You do realize my comment was sarcastic right?

Anyways back on the topic at hand: Trying a larger heatsink later today or tomorrow off a P4.

I've never had a use for more than 3-5Amp before with a bridge, so I didn't expect heat to rise that quickly.
 
I guess your sarcasm was too subtle for me. It looked like you meant it.

Bob

Yea, I've been told that by so many people, I need to find a way to make that more clear...




Already ruined the drill bit... Time to get one that will get though aluminum...
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Oh, and place the fuse between the transformer and the rectifier, not after the rectifier.
 
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