SMPS oddities

Bizarre. They use

TR for transformer

T for transistor

P for pot

TH for SCR

DZ for zener

Ghastly mess, obviously hacked by an amateur.

John

mode.

voltage

turned

threshold,

rectified

lower

assume

a.k.a. "Thyristor"

Nope, most likely German. I remember that kind of supply from the early semi-transistorized color TV sets. And yeah, the slightest hickup ... BANG! Usually followed by a plume of smoke and a stench.

DZ is unusual though, they normally used Z oder ZD.

--
Regards, Joerg

http://www.analogconsultants.com/

"D" is required by simulators for diodes, Zener or otherwise.

So I personally use "DZ" just for clarity of understanding by the client.

But the other designators above are _truly_ bizarre.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave

Not if you work in different languages. It does become bizarre when one encounters stuff like I did in one French schematic: L as in "lampe" for transistor ...

Other countries' engineers find some of our designators such as CR a bit bizarre.

I love Italian schematics. Unita d'alimentazione sounds so much nicer than power supply.

--
Regards, Joerg

http://www.analogconsultants.com/

Most of us have cut over to "D" for diode, since surface-mount dynamotors aren't too common anymore. [1]

But amateurs continue to make up designators, like IC and RV and RP and TR and LED and silliness like that.

Or PSU. The Brit thing "+ve" continues to weird me out. They apparently think it means "positive", but I read it as "plus V-sub-e"

GE process control schematics used to just assign a number to each part, no alpha prefix at all. A resistor was just "98"

John

[1] if fuel-burning pcb-mount MEMS turbogenerators make it to market, what will we call them?

Some companies do that. The first four numbers tell you what kind of part it is, like 7.5mm long carbon resistor, the next four refer to one unique part, or similar. There used to be a deciphering scheme for the most popular numbering conventions but I can't find it anymore.

G?

--
Regards, Joerg

http://www.analogconsultants.com/

[snip] [snip]

That's patent-style... number everything, but require reading the text to (try to) sort out everything :-(

...Jim Thompson

-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | |

| 1962 | America: Land of the Free, Because of the Brave

I don't think so, my info is that it's a power supply for a TV set. Most probably it is Italian or German, thus the uncommon component designation.

Erm... anyone has any idea regarding my question? :)

Cheerz

-- bitman

Looks very German to me. I grew up there and repaired lots of TVs when I was a kid. Then gave them away because the programming was so boring :-)

Probably something like this: The secondary reaches a level where there will be 7.5V across DZ301 and then DZ301 begins to conduct. That allows T301 to draw current and that triggers Th301.

--
Regards, Joerg

http://www.analogconsultants.com/

First, this isn't a service schematic, merely one that shows parts in, let me guess, Assy300. It contains no functional timing, phasing or control voltage information that would allow it to be easily repaired or duplicated.

The pencilled-in connection between board terminals M'1 and M'4 are highly suspect.

It is, however, by inspection, a flyback topology that is voltage regulated. Peak primary current is varied, but not regulated, as such. Voltage feedback is obtained through transformer coupling on C303.

As voltage increases, T301 turns on, biasing TH301 gate closer to the firing threshold., reducing the peak voltage required on R317 to turn off T302.. It is not obvious whether TH301 is actually used as a cycle by cycle turn-off generator; it will handle overcurrent by default, in the absence of feedback volt-seconds, but will not extinguish any where near as quickly.

Turn-on is regenerative, but baker clamped, so no no great drive current is required to initiate turn-on of the discontinuous primary switch.

As far as naming conventions go, it seems no-one has had difficulty understanding them, in spite of the circuit's European origins >>

twenty years ago.The L200 has been around since the late 70's.

RL

Sir.

Cheers,

Phil Hobbs

Presumably amateurs were the ones who came up with the now-common standards as well...

I think the real problem is folks who run off and decide to come up with their own standard without doing a little research first to see what the common standards are. I don't think there's anything particularly bad about using, e.g., "LED" so long as you're aware that it's uncommon and that the common solution is just "D". Do you? (And no, I don't personally use "LED" :-) )

I keep hoping that someday schematic capture programs will support the use of subscripts in pin names. Something like the TeX standard -- Name_{Subscript} or Name^{Superscript} -- would work fine.

Wasn't that because the government mandated you could only tune in one station, like (supposedly) North Korea does today? :-)

No, the programming was actually a bit better than in the US although I've heard that they now also have more of those dreaded talk shows. We used to have three channels, plus Dutch and Belgian TV. I liked Archie Bunker back then, plus some of the older movies, some of which we taped and took along. But it was similar to the pong game. I built one, played it once and then gave it to a class mate at the high school. Entertainment in a can just isn't my thing.

--
Regards, Joerg

http://www.analogconsultants.com/