First, I noticed the caps are filling up to about 16VDC, even though they're getting 13. I think this is because I don't have a bleeder resistor on there but I'd like to know specifically why they fill up to 16 in the first place? Why that number? What's the best way to limit this to 13V?
That transfo... what was it pulled from? The winding you are using is just one of several.. Agile Magnetics appears to wind custom stuff in 100VA, 250, 500, etc.. sizes and this model (RMS-12) looks to be 250VA. I have just 3 questions:
- What test's have you done on resistance and continuity between all the winding's (I count at least 13 wires here..)
- If the front bottom is the primary, why does it have 5 wires? (120/240v primaries often require use of 2 winding's in parallel)
- Can you measure the other 3 secondary winding's with a real meter? (surely that can't be the only meter you have..)
On a guess, the 2 red winding's carry the bulk of the output (perhaps audio PA), the yellow could be for pre-amp, and the grey winding you are using is good for maybe 500ma of panel lamps, etc.. (hence the sag with 850ma of load).
That transfo... what was it pulled from? The winding you are using is just one of several.. Agile Magnetics appears to wind custom stuff in 100VA, 250, 500, etc.. sizes and this model (RMS-12) looks to be 250VA. I have just 3 questions:
- What test's have you done on resistance and continuity between all the winding's (I count at least 13 wires here..)
- If the front bottom is the primary, why does it have 5 wires? (120/240v primaries often require use of 2 winding's in parallel)
- Can you measure the other 3 secondary winding's with a real meter? (surely that can't be the only meter you have..)
On a guess, the 2 red winding's carry the bulk of the output (perhaps audio PA), the yellow could be for pre-amp, and the grey winding you are using is good for maybe 500ma of panel lamps, etc.. (hence the sag with 850ma of load).
"Tests"
"Windings"
It's plural not possessive, so lose the apostrophes, or wait... is that apostrophe's... lol
That transfo... what was it pulled from? The winding you are using is just one of several.. Agile Magnetics appears to wind custom stuff in 100VA, 250, 500, etc.. sizes and this model (RMS-12) looks to be 250VA. I have just 3 questions:
- What test's have you done on resistance and continuity between all the winding's (I count at least 13 wires here..)
- If the front bottom is the primary, why does it have 5 wires? (120/240v primaries often require use of 2 winding's in parallel)
- Can you measure the other 3 secondary winding's with a real meter? (surely that can't be the only meter you have..)
On a guess, the 2 red winding's carry the bulk of the output (perhaps audio PA), the yellow could be for pre-amp, and the grey winding you are using is good for maybe 500ma of panel lamps, etc.. (hence the sag with 850ma of load).
"Tests"
"Windings"
It's plural not possessive, so lose the apostrophes, or wait... is that apostrophe's... lolI was never good as a writer, but I did manage to learn Spanish over-sea's (it's possible my English is messed-up now, but now I'm too old to give a crap..)
Use a decent size PC power supply with a couple large super capacitors on the 12 volt output...
If you want to limit the voltage to 13 V you will need a voltage regulator. However, building your own regulated 12 V 10 A power supply is more complicated than you can achieve with just the basic parts you have assembled so far.
You can always salvage a good beefy tranformer and many parts from an old car battery charger, look at local goodwill store or craigslist. There's your learning to built from parts...
My goal is to tell myself "I wanna build this thing to these specs completely with my own parts" and then execute it. I plan on wasting tons of money buying random parts I may or may not use, as long as the final product is what I set out to build.
I'll find a use for the stuff I buy sooner or later.
You can always salvage a good beefy tranformer and many parts from an old car battery charger, look at local goodwill store or craigslist. There's your learning to built from parts...
Already beat you to it lol. This is how this whole idea got started actually. The transformer was actually shorted internally so it drew 5A at idle with no load, but I tried my best to bring it back to life.
What are the voltages of the other secondary windings? You certainly have 250va of transfo there, but getting the expected amperage depends on knowing the characteristics of what you have. Do you have at least a $10 multi-meter to report back some results? Keep in mind if the primary windings are 240/120v, you'll want to in-phase parallel 2 of them or you'll be getting only half capacity.
My goal is to tell myself "I wanna build this thing to these specs completely with my own parts" and then execute it. I plan on wasting tons of money buying random parts I may or may not use, as long as the final product is what I set out to build.
That is a healthy attitude - but be careful. You can end up with tons of 'stock on hand'. Just look around these boards for people whose 'collection' of stuff is an embarrassment, if not shame.QuoteI'll find a use for the stuff I buy sooner or later.... famous last words.
By all means learn - and mistakes are a good way to do that, as long as they don't involve injury or destruction of property. (Blowing the side out of a TO-220 package is allowed ... and inevitable).
Looks like you went to town with the mdf and cable ties
Looks like you went to town with the mdf and cable ties
Oh yea, of course. I like to make my installs look good, even if it's just a stupid experiment. It actually worked just fine outside the box but after assembly it failed. It's the same setup, so I'm assuming the blown transformer finally gave out. Now it's just a heavy paperweight. Or a door stop. Oh well, it looks cool lol.
I have bins and buckets of "I'll use this someday" hardware and parts. And the problem is the buckets keep multiplying...