Diary PCBuds mini-grow

[f-e]

January?
I would look at 200v 400v 450v and maybe 820uf if space is tight for a higher voltage rating.
I get 'one off' caps from eBay

A bust TV or PC PSU might offer up something.

Perhaps 3 caps of 330uf would be cheaper. It's a more common size and a pack of 5 generally cost little more than a single

 

[exploziv]

Great advice f-e.
you should find something in a old pc psu for sure.
Also, here you can still find them locally, at some hobbyist shop, kinda cheap. You should look into that as well. Personally I would cancel that order. You will forget about it till it comes. Usually its just over 3 weeks. But it may take more.

 

[PCBuds]

I went through 4 boxes of old electronic parts and didn't find anything.

All my stuff is low voltage.

But then I saw this.

​


It's my microwave/toaster oven combo.

The microwave part of it crapped out a couple of years ago, so I bought a new microwave.

I still use the toaster oven part of it almost daily.

I'll bet there's some good parts inside?

​


My mom bought it for me for my birthday in 1990.

It still works!! (partly)

​





But then I looked at my plant and realized that she is fine.

She has two working amps feeding her, and I have a new amp coming.


I don't need 4 amps.


I can just wait for my capacitor to arrive.

My cat was saying "what the hell do you want to rip your trusted microwave apart for?"

​​​​​​​

 

[PCBuds]

This is one very proper plant !!!

I took a couple of pictures while she was sleeping.
Shhh... don't wake her. Lol

 

[PCBuds]

 

[PCBuds]

 

[PCBuds]

 

[PCBuds]

I looked inside my microwave/toaster oven, but no luck.
Just a 2,100 Volt cap with only 0.77 micro farad.

My microwave was trying to say "No PCBuds!" LOL

I'll keep looking around, I might find a capacitor somewhere.

 

[PCBuds]

January?
I would look at 200v 400v 450v and maybe 820uf if space is tight for a higher voltage rating.
I get 'one off' caps from eBay

A bust TV or PC PSU might offer up something.

Perhaps 3 caps of 330uf would be cheaper. It's a more common size and a pack of 5 generally cost little more than a single

What about this for a test ?

It's probably too low of a voltage ?

It looks like 110v in. With rectification to DC where a 0v is found. So...110 gives about 160? so 80-0-80 rails.

I remember that from school.
We've got 120 VAC but that's the RMS value, the peak voltage is 120÷ 0.707=170V peak to peak, so 85V for half the wave.

I'd probably pop the 80V capacitor right ?

 

[f-e]

I would stick with 200v rating or more. To me it looks like the two caps are sharing the voltage, but it's a bit unusual if they are.
The cap won't be found in older gear. Only in lightweight modern kit, that uses switchmode like supplies. Older gear uses your 110 and a big transformer to change it. The size of that transformer is based quite obviously on wattage, but not so obviously, frequency. At 60hz the transfer of power is not very efficient. At 60khz the transfer is much more efficient, so the transformer can be physically smaller. Weigh up an old 500w amp, beside your 500w PSU. The difference is that transformer. A resource heavy component. Like a few Kg of metals. Thus, they now take your 110vac and make it DC. This DC is they pulsed (probably back n forth) at maybe 100khz like a fake 170vac 100khz. The brains of the operation watch the low voltage caps at the output of the psu, to decide when to fire the 100khz to top them up.

Your car amps are much the same. They take the 12vdc and fire it back n forth through transformer to create a more useful voltage, such as +/- 30vdc. This high rate and high power switching is usually done with banks of parallel fets (field effect transistors). A bank for each half of the back n forth.

12vdc it on the left. Low impedance reservoir caps. Bank of fets top and bottom. Transformers looking shiny. End of each bank a diode pack to rectify the output back to DC. Brain chip dead center, beside the smoothing caps of the amp stage that follows. This is pretty much what you have, but easier on the eye.

A PC PSU is your best chance. 500w is common and they all use this kinda switching tech.

 

[PCBuds]

Thanks f-e for all your information.
I have enough electronics knowledge to understand everything you said.

I remember being in electronics class in the early 80's when field effect transistors were first introduced to the home stereo market.

There was a company (Carver I think?) that introduced the first home stereo amp with FETs, it had 50 Watts RMS continuous per channel into an 8 ohm load.

The amp was a 6-8 inch cube and people were blown away !!

How could such a small package deliver that kind of power ?!!??




I'll keep looking around for a test capacitor.

I assume that there is no point in looking inside any of my old car stereo stuff ?


I've got a PC PSU that I can look into.

It was just a couple of months ago that I threw out all kinds of boards and stuff that I've had for 15 years or more.

It always happens that way.

 

[PCBuds]

I found this, but it looks too small to have a big capacitor even fit inside.

This looks promising.
It's a 60 Volt charger for an ebike.

Score !!

It's not big enough to replace the bad capacitor even with both connected in parallel, but it will work for a test.


I kinda think running two caps, each for half the wave is common in Canada and the US because of our 120VAC ?

 

[PCBuds]

Shit !!

I got the capacitor installed with a new 4 amp fuse and popped a signal diode and the fuse.

I saw the signal diode burn up, so I know what blowed up.

​

​​

​

​​

​

​​

​

​​

​

​​



I'm 90% sure that I got the polarity of the capacitor correct.

Perhaps the imbalance of capacity between the two capacitors caused the problem?

That signal diode was fine with the old capacitor reinstalled. It wasn't until I soldered in the 220 microfarad capacitor that it was unhappy.




I'm done experimenting for now.
Im getting pretty drunk and stoned and don't want to make things worse.

I'll wait for the proper capacitor to arrive before I mess with it again.




I've got a few signal diodes that I could try to install when the capacitor arrives.

I kinda forget about the ratings on signal diodes.

Are they pretty much the same?

I remember about zener diodes, but I forget how they are rated.

​​​​​​​It might be hard to read the code on the diode now that it's all smoked. Lol

 

[PCBuds]

I could probably install both capacitors from the 60 volt psu, so they are balanced, but now I've got a cooked diode. Lol

 

[PCBuds]

By the way,.. your guess is better than mine...

If you have any input, that would be great.


It took a lot of restraint on my part to not though it out when it first popped the fuse.

I tend to hold on to broken crap for more than 15 years. Lol


We can do an autopsy. Lol

Maybe I can learn something about signal diodes ?...

 

[PCBuds]

My plant around September 10th...

My plant now...

​​​​​​​

 

[PCBuds]

 

[PCBuds]

My EC meter arrived today.

This is what it's reading...

So I'm using 1/2 tsp of Maxibloom, 1/2 tsp of Calmag, 1/2 tsp of Potassium Silicate, and 1/4 tsp of Liquid KoolBloom, mixed into just over 2 liters of water.

So, I guess I'm doing everything wrong.

I've got way too much light, way too much fertilizer, not enough CO2, and hardly any leaves on the plant.

But it really does seem to be working for me. Lol

I'm quite happy with my plant.
It looks good to me.

 

[PCBuds]

 

[PCBuds]

My new power supply and fuses arrived.