Linear power supply is really a primitive switcher operating at 120Hz. Current is drawn from the mains in narrow spikes of high amplitude, that become wider when load increases. In addition rectifiers become reverse polarized at the peak of the voltage conducting for a moment in the opposite direction creating narrow spike that couples to any, even smallest inductance in the circuit.
The fact that current is drawn in narrow spikes has serious consequences. Transformer has to be larger than one with resistive load, because higher rms to average current ratio is causing bigger losses in windings, while high frequency content increases core losses (eddy currents, hysteresis). These narrow current spikes of high amplitude travel thru fuse and power cable making things very complex.
As for the power delivery, it should be obvious from the definition of electric current (flow of electric charge), that the exactly same amount of electric charge leaving one leg of power supply comes back in another. Power has to be delivered different way. Current in the wire creates magnetic field around conductor while presence of load makes voltage drop - an electric filed. These fields cross each other like X-Y axis while Z axis perpendicular to them shows direction of the power delivery (Poynting vector). Power is absorbed by the load from electromagnetic wave.
To improve linear power supply circuit I would look for “soft” rectifier (like Hexfred) , that, after conducting for a moment reverse polarized, don’t snap back too fast (wider spikes are better). I would also look for low inductance electrolytic capacitors, like “slit foil” type. 0.1uF capacitor in parallel helps, but with large inductance of main capacitors can create parallel resonance circuit and possible ringing.
An argument for fuses and maybe power cables in power amplifier
There are a lot of discussion about fuse but I don't remember a thread that include
an actual circuit.
The circuit below is called a rectifier which converts AC voltage from the wall to DC voltage that feeds to audio power amplifier. All if not most power audio amplifier uses this topology. Some have bigger transformer, some have more capacitors, some have higher voltage output but most are more or less the same. Audio amplifer uses a lot of current so they don't use a regular which may even degrade the supply, therefore most will just use what you see below as a rectifier circuit.
You can see from the circuit the current comes from the wall, the AC source far left, to the fuse, F1 5A upper left, go through the transformer then to the diode rectifier, D1 D2 D3 D4, then finally to the 25+/- supply source which then will feed to the power audio amplifier.
So you can see the fuse is clearly in the signal path.
As for the power cable, it is harder to understand. Most power cable are already beefy enough to handle the current so having an even beefier cable will help is something that needs further reasoning.
- ...
- 16 posts total
@rodman99999 .....*slow clapping* { it's late....the cats are asleep} Thenk you, Dr. Whiplash..... ;)
....and, given that bit of clarity; 'X' = Infinity, macro v. mega, everywhere in everything...even in the 'nothing' of space....
Back to the Theories! *G*👍 Actually, rodman9x5, that was actually entertaining..... |
Funny! AND: a snowflake had me deleted, just recently, for saying, "it's like teaching a box of rocks, to sort your socks!", in their exhausting, er.. I mean: exhaustive thread. Put another way: The problem with naysayers isn't that they're ignorant. Rather: it's they're knowing so much that's incorrect*. *The very heart of Dunning-Kruger Happy listening!
ps: The nines are exponential.
|
"DeeeKay, have it Your Way!" Ah...ASCII Art....been awhile... I remember when we used to chisel that into the nooks 'n crannies to confuse the archaic-ologists and please the tinfoil hat crowd.... Now? ....just type...*sigh*.... Better laughs to chisel in "Don't move this block!" on a face; on the opposite side, "See? Told you....'nuthin'." just before it would tip over onto them.... PP.....Pyramid Pranked. "Exponentially BTW, Dr. Whiplash was a 'proprietor' of a "Miracule! Liniment! that will cure Everything from muscle ache and pulls, gout, headache, heartache, ..." I've got nearly enough line power cords to nearly knit a net with pool cues (some smart*ss wrote a book on the subject....honest! ) As noted:
if it's not for such as this...for me, perhaps you, with this little ditty from the DB's....
why?
...best of your days, J
|
- 16 posts total