TOP200 15W PSU project

[ben7]

So today I looked in my box of junk and came across a TopSwitch 200.

Its a easy to use controller for SMPS, and I made a small psu on breadboard already. Seems to go into shutdown with a slight load, so I think I have to try a different transformer. Here is the circuit that I used (TOP200 is slightly less powerful than TOP202, but in same package and pinout). Pics to come tm!

[ben7]

Re: TOP200 15W PSU project

Darn!

Well I accidentally pushed the snubber off the breadboard while taking measurements, and of course within seconds smoke came out of the TOP200 ....

[momaka]

Re: TOP200 15W PSU project

Oops .
High voltage and high current always guarantees cool fireworks, especially on a breadboard.

Try putting a 10, 20, or 30W light bulb in series with the PSU next time. That way, if something goes wrong, light bulb will become lit and you may be able to save your components (of course, if your light bulb is too powerful, components in the PSU will eventually overheat and burn - still, you would have some time to react when you see the light bulb becoming lit).

[ben7]

Re: TOP200 15W PSU project

Oops .
High voltage and high current always guarantees cool fireworks, especially on a breadboard.

Try putting a 10, 20, or 30W light bulb in series with the PSU next time. That way, if something goes wrong, light bulb will become lit and you may be able to save your components (of course, if your light bulb is too powerful, components in the PSU will eventually overheat and burn - still, you would have some time to react when you see the light bulb becoming lit).

Yeah I might use a lightbulb next time. I have been using two 14v 28w transformers back to back for isolation

The TOP200 squirted out a bit of black goo when it fried xD

[momaka]

Re: TOP200 15W PSU project

Yeah I might use a lightbulb next time. I have been using two 14v 28w transformers back to back for isolation

Ah ok, at least you're using some kind of current-limiting protection. I thought you were just plugging things straight into the mains.

The TOP200 squirted out a bit of black goo when it fried xD

Well, I myself had 2 incidents as well last week, in both of which I ended up killing caps - and not just any caps but good caps (a 16V 1500uF Rubycon MCZ and a 16V 330uF Panasonic general purpose cap). Both overheated and bulged . Reason for that was because I accidentally misplaced the jumper for their ground and instead had it wired to 12V. The (+) side of these caps was connected to the 2.5V output of a buck-regulated power supply that I was building and testing. So basically those caps were in reverse at almost 10V. The Panasonic actually held in there pretty long - took me several minutes of testing the circuit before I noticed it was bulging. After noticing, I though maybe it was inadequate so I substituted it with the Rubycon and changed the minimum load resistor on the 2.5V output to 10 Ohm (since the circuit was unstable and I thought this would help). It took only about 10 seconds of runtime before I noticed the Rubycon was very hot and bulging as well. Only then I started checking my circuit and found my mistake

I cut the vent on the Rubycon today to see if the pressure was gone - it wasn't! Thankfully I was wearing safety goggles and was pointing the cap away from my face when I did this - it did spray a lot of electrolyte out. The Panasonic is still bulged and hard as a rock, so it probably still retains its electrolyte. Might vent it as well.

Definitely need to give these troopers proper burial ceremony . Maybe even a 21-gun salute.

[ben7]

Re: TOP200 15W PSU project

Ah ok, at least you're using some kind of current-limiting protection. I thought you were just plugging things straight into the mains.


Well, I myself had 2 incidents as well last week, in both of which I ended up killing caps - and not just any caps but good caps (a 16V 1500uF Rubycon MCZ and a 16V 330uF Panasonic general purpose cap). Both overheated and bulged . Reason for that was because I accidentally misplaced the jumper for their ground and instead had it wired to 12V. The (+) side of these caps was connected to the 2.5V output of a buck-regulated power supply that I was building and testing. So basically those caps were in reverse at almost 10V. The Panasonic actually held in there pretty long - took me several minutes of testing the circuit before I noticed it was bulging. After noticing, I though maybe it was inadequate so I substituted it with the Rubycon and changed the minimum load resistor on the 2.5V output to 10 Ohm (since the circuit was unstable and I thought this would help). It took only about 10 seconds of runtime before I noticed the Rubycon was very hot and bulging as well. Only then I started checking my circuit and found my mistake

I cut the vent on the Rubycon today to see if the pressure was gone - it wasn't! Thankfully I was wearing safety goggles and was pointing the cap away from my face when I did this - it did spray a lot of electrolyte out. The Panasonic is still bulged and hard as a rock, so it probably still retains its electrolyte. Might vent it as well.

Definitely need to give these troopers proper burial ceremony . Maybe even a 21-gun salute.

Haha lol, exploding caps aren't funny!
I almost had a 2200uF 35v cap go off in my face before, I realized it had bulged and I could hear it bubbling. Accidentally reversed polarity xD

And lol noo, I would never plug projects straight into mains!