power unit
ZXNet echo conference «real.speccy»
Can anyone tell me how many amperes should be at the +5 and +12V output in order
to pull the Spectrum and 2 drives. And how much should be the total capacity
of the power supply.
For now... for now!
WT> Can anyone tell me how much Ampere should be at the
WT> output +5
Very relative:
Soviet 5'25: 12V ~ 0.6-0.8A
5V ~ 0.8-1.0A
(each)
For imported ones, these limits can fluctuate greatly, but as
usually always to the lesser side.
For 3'5, the parameters are stamped or written on the drive - you'll see for yourself.
WT> in order to pull the Spectrum
Also very vague, How do we know what you have installed there? If we look at the average board, then 1.0-1.5A.
WT> And how much should the total capacity of the power supply be?
P(i) = U(i) * I(i);
Psum = SUM (P(i));
And why do you need this anyway? Buy a power supply from a PC and
don’t reinvent the wheel.
In a message of 30 Aug 01 Witalij Tzarkov wrote to All:
WT> Can anyone tell me how many amperes should be at the output +5 and +12V
WT> in order to pull the Spectrum and 2 drives. And how much should be
WT> the total capacity of the power supply.
The power supply from the pussy will satisfy all your most modest desires :)
WBR, EmP^A1C
Thu 30 Aug 2001 at 20:30:17 Witalij Tzarkov -> All on the topic Power supply
WT> Can anyone tell me how many Amps should be at the output
WT> +5 and +12V in order to pull the Spectrum and 2 drives. And
WT> how much should be the total capacity of the power supply.
Here everything depends on the computer board (model) and what
additionally is installed on it. Pentagon, Scorpio, Kai without additional devices consume about
1.5 A, but I advise you to give it up to 2A for uninterrupted operation. This is at 5
volts, and at 12 the current is insignificant, about 20 mA. There it is only needed for VG93.
For a 5.25 disk drive, I use (in calculations) 1.5A at 5 volts and 1A at 12
volts, although it is possible that less is possible.
The 3.5 disk drive takes about 300 mA at 5 volts, 12 V is not used.
Peripherals (Skorpovo keyboard controller and SMUC controller) take 300 mA.
These are the layouts. When choosing a power supply, I strongly advise
to use power from the PC. This kind of thing pulls everything so that you don’t bet on your
Spec. It dampens all interference from the refrigerator and other household appliances and besides
it is very reliable.
Sincerely, Alexander Kushnikov aka Sander.
In a message of 31 Aug 01 Alexandr Kushnikov wrote to Witalij Tzarkov:
AK> These are the layouts. When choosing a power supply, I strongly advise
AK> to use power from the PC. This kind of thing pulls everything so that you don’t bet
AK> on your Spec. It dampens all interference from the refrigerator and other household
AK> appliances and is also very reliable.
It depends on your luck. When the Chinese skip the input CLC filter, it glitches a lot...
Bye...
31 Aug 01 23:21, Alexandr Kushnikov wrote to Witalij Tzarkov:
AK> power supply, I strongly advise you to use power from the PC. This
AK> pulls everything so that you don’t bet on your Spec. It dampens all
AK> interference from the refrigerator and other household appliances and besides, it is very
AK> reliable.
This enemy power supply may one day burn down the Spectrum.
KF> This enemy power supply unit may one day burn down the Spectrum.
If +12V blocking is installed on the VG in the absence of +5,
then I see no basis for your statement.
Although this is also just a precaution - my Pentagon
has been working with the PC unit for almost two years now and there are no problems
about this it was, and in general, why would they.
DR> If +12V blocking is installed on the VG in the absence of +5,
DR> then I see no basis for your statement.
What does this have to do with it? The VGshka is not the whole Spectrum.
DR> Although this is also just a precaution - I have a Pentagon
DR> has been working with the PC unit for almost two years now and there have been no problems
DR> about this, and in general, why would they.
Do a short circuit.
In the pisish power supply, there is either no protection at all or it somehow works strangely.
In short, when you remove the load, the +5v voltage jumps to abnormal values.
DR> If +12V blocking is installed on the VG in the absence of +5,
DR> then I see no basis for your statement.
DR> Although this is also just a precaution - my Pentagon
DR> has been working with the PC unit for almost two years and there have been no problems
DR> in this regard, and in general with Why would they.
Not quite like that. In fact, if +12 disappears and +5 remains on the VG, then she is a bastard and will definitely fly out, but not vice versa. We have already come across 4 such computers.
DR> --- GoldED/386 3.0.1-asa9 SR1
DR> * Origin: Magic Of Eternity (2:5052/4.15)
Until... bye!
KF> Make a short report.
Are you collecting materials for “Bad Advice?” ;-)
KF> In a pisish power supply, there is either no protection at all, or it’s strange
KF> it somehow works. In general, if you short, then when
KF> you remove the load, the +5v voltage jumps to
KF> abnormal values.
Shorting a 150-250 watt power supply, uh, how would it be
softer... You need to be more careful. This time. Secondly, the fact described by you is strange, I had a case of short circuit, but the power supply just stalled and did not start until I turned the power off/on.
You probably have a power supply of the wrong assembly. ;-)
KF> Do a short circuit.
Did. And +5 to the ground, and +12 to the ground and +5 to +12 did... I didn’t have anything on fire from
this - the power supply itself just went out.
KF> In the pisish power supply, there is either no protection at all or it somehow works strangely.
KF> In general, if you shorten it, then when you remove the load the voltage +5v
KF> jumps
KF> to abnormal levels meanings.
Not in each. bp bp discord. I have a Chinese standard one for 160W and I’m not complaining,
on the contrary, everything that can be hung on a speck, unlike standard ones, works.
Bye, Kirill.
tigr...@mail.ru Tigrr/BW/XPJ http://brainwave.dax.ru
KF> Do a short circuit.
;)
KF> In the written power supply there is either no protection at all or it’s strange that it somehow
KF> works.
KF> In general, if you short it out, then when you remove the load the voltage +5v
KF> jumps to abnormal values.
If only there was a jump. In most AT power supplies from the PC there is no protection at all against short circuits, and with a short circuit both power transducers remain open!!! I hope it is clear what can happen in this case, given that they are connected in series to the network and in parallel to the load trans. Don’t say anything, but this is really true, and during a short circuit, both transducers, the high-voltage diode bridge,
air conditioners with a 220 filter and PWM microphone burn out;(
WT> Not quite like that. In fact, if +12 disappears and +5 remains on the VG, then she is
Quite so.
WT> the bastard will definitely fly out, but not vice versa. There are already 4 such computers
WT>
Strange. My VG crashes all the time only in the absence of +5 and the presence of +12...
Or in the absence of land. But +5 without +12 NEVER crashed. And I have already burned more than 8 pieces in total (I just have 8 buildings left, but I don’t remember how many I threw away). And if it comes to that, then why the hell do all the defenses invented for
VG not apply +12 to it in the absence of +5, but not vice versa? Check it out if you don't believe me :) Yesterday I cut off +12 because I had to, and nothing, as you can see...
Bye, Witalij.
tigr...@mail.ru Tigrr/BW/XPJ http://brainwave.dax.ru
03 Sep 01 07:45, Witalij Tzarkov -> Denis Rybakov:
[skipped]
DR>> If +12V blocking is installed on the VG in the absence of +5,
DR>> then I don’t see the basis for your statement.
[skipped]
WT> Not really. In fact, if +12 disappears and +5 remains on VG
WT>, then she is a bastard and will definitely fly out, but not vice versa. There have already been 4 such
WT> computers.
Strange, strange.
For how long I powered the computers only
from +5 - not a single VGshka crashed...
And all the documentation says that dangerous
is precisely the presence of +12 in the absence of +5.
Aleksandr
Somehow, Igor Turashev wrote to Kirill Frolov:
IT> I did. I did +5 to the ground, and +12 to the ground, and +5 to +12... I didn’t have anything on IT from this - the power supply itself just went out.
After a similar (accidentally short-circuited) experiment with a pisish brand
block, 4 RU-shki and 2 KP-shki disappeared. :( The spec is still not working, because
after replacing it, it began to periodically hang up or display dirt on the screen.
Sincerely, Quasar.
And it should go out before the network is turned off with a delay in this state of seconds
by 5...
DR> Short-circuit the 150-250 watt power supply, uh-uh, how would it be
DR> softer... You need to be more careful. This time. Secondly, it is strange and
DR> the fact described by you, I had a case of short circuit, but the
DR> power supply simply stalled and did not start until
DR> turned the power off/on.
DR> Probably you have a power supply of the wrong assembly. ;-)
Looks like it...
[I ZX] [Team Guardian] [Team Kelly]
Hasta la vista.
Tim Kelly
... np: Billy Gilman - Shes Everything You Want
WT> Not quite like that.
Do you want to argue?
WT> In fact, if +12 disappears and +5 remains on the VG, then
WT> she is a bastard and will definitely fly out, but not vice versa.
Let's arrange a vote. ;-)
It does not crash in the absence of 12V (but if a disk is inserted, it can screw up
it - there will be no more serious consequences), but if you submit
exactly _12_ in the absence of _5_, then you can go buy
a new one in advance.
WT> There have already been 4 such computers.
Good disease sclerosis...
(No offense)
SP> In most AT power supplies from the PC there is generally
SP> no protection against short circuits,
You need to buy the “correct” units.
SP> and with a short circuit, both power transducers remain
SP> open!!! process, when one transistor began to open, and the second
had not yet closed completely. To eliminate this, corrective circuits are introduced, and a pause is introduced between switchings, the TL494 itself does this (as a rule), and does it completely. successfully.)
SP> Whatever you say, it’s really so, and during a short circuit
SP> both transistors burn out, the high-voltage
SP> diode bridge, the air conditioners on the 220 filter and PWM
SP> mikruha;(
The fact that the transistors burn from natural
overload (unless, of course, protection is implemented),
this is not yet a reason to invent all sorts of fables
and rub them into the gullible population.
AS> After a similar (accidentally short-circuited) experiment with a pisish brand
AS> block, 4 RU-shki and 2 KP-shki disappeared. :( The spec is still not working,
AS> because
The assembly is not the same :) China rules :)
AS> after replacing it, it began to periodically hang up or display dirt
AS> on the screen.
So, either the soldering was like that, or I didn’t notice something else... But maybe somewhere
the power supply path was burnt out. Did you short-circuit it on the computer itself or before the board?
Bye, Alexander.
tigr...@mail.ru Tigrr/BW/XPJ http://brainwave.dax.ru
Tuesday 4 Sep 2001 12:51:48, Igor Turashev -> Witalij Tzarkov:
IT> I don’t remember). And if it comes to that, then why the hell do all
IT> protections invented for VG not give it +12 in
IT> the absence of +5, but not vice versa? Check it out if you don't believe IT :) Yesterday I cut off +12 because I had to, and nothing,
IT> as you can see...
I have a burnt power supply, which I'm currently tormenting in an attempt to restore
the protection just cuts off 5 if not 12. Although on my computer
it happened: the diode bridge at 12 burned out, and the computer worked for several seconds without +12,
nothing, everything is fine, the VG did not crash.
Regards, Dmitriy.
Monday 3 Sep 2001 07:45:44, Witalij Tzarkov -> Denis Rybakov:
WT> Not really. In fact, if +12 disappears and
WT> +5 remains on the VG, then she is a bastard and will definitely be eliminated, but not
WT> vice versa. There have already been 4 such computers.
There was such an accident. To my surprise, nothing happened to VG.
With respect, Dmitriy.
Once I received a letter from Alexander Seleznev to Igor Turashev ...
AS> After a similar (accidentally shorted) experiment with the pisish
AS> brand block, 4 RU-shki and 2 KP-shki disappeared. :( The spec is still
AS> still not working, because after replacing it it began to periodically hang up
AS> or display dirt on the screen.
And +12 to +5? My first scorpion worked for ~2 seconds :) :(
Konstantyn
AK>> yet he is very
AK>> reliable.
KF> This enemy BP can one day burn the spectrum.
Either do not believe nonsense, or justify!
Scorp has been working for me for almost three years and I have no complaints.
KF> Do a short circuit.
Maybe it would be better to throw it from a skyscraper? ;-)
KF> In a pisish power supply, there is either no protection at all or it’s strange
KF> somehow it works.
KF> In general, if you shorten it, then when you remove the load
KF> the +5v voltage jumps
KF> to abnormal values.
And the fuse won’t save you?
KK> And +12 to +5? My first scorpion worked for ~2 seconds :) :(
Did it really work? Usually the TTL, when about 6V is applied to it, already burns out, but does not work
not even once...
Bye, Konstantyn.
tigr...@mail.ru Tigrr/BW http://brainwave.dax.ru
DR> 8-( )
Don’t be so surprised!
DR> Explain to me, friend, how can they open at the same time,
DR> if they are controlled in antiphase from the matching
DR> transformer?
Yes, they work in antiphase, but the circuit it is constructed in such a way that the base bias resistors are on the order of 200K, and the winding resistance does not exceed several ohms. Let's assume a short circuit occurred. This abruptly disrupts the generation, while one of the transistors is opened by the bias of the trance winding, and the second at this moment opens due to the transistor EMF pulse during a short circuit. Although this should not happen, it has been proven
by the bitter experience of repairing more than a dozen PC's power supply units.
DR> (To be completely precise, a through current can
DR> arise, but only at the moment of the transition process,
DR> when one transistor began to open, and the second
DR> by this time did not have time to complete close.
This is what I meant. But since the current through the transistors is quite large, and the resistance of their transitions at this moment turns out to be small, then the collector junction breaks down (most often), then the current increases for the second,
open EMF. transistor, and it also burns out. Under certain conditions, due to these transient processes, the voltage on the separating electrolyte can greatly increase and, consequently, its output from standstill. At the same time, a strong impulse occurs in the secondary circuits.voltage, which can burn out the microcircuit, which is what it usually does;( But
it looks like this is a topic for another echo.
DR> To
DR> to eliminate this, corrective circuits are introduced, and a pause is introduced
DR> between switchings,
But the capacitance of the condensers in these circuits is enough for instant overheating of
transistors.
DR> the TL494 itself does
DR> this (as a rule), and does it
DR> quite successfully.)
Except that it also dies in the process;(
KF>> the +5v voltage jumps to abnormal values.
AK> But the fuse won’t save?
The fuse very rarely saves, because
it will burn out last of all knocked out in the event of an
accident due to its inertia. Basically, it
is placed there to prevent
the complete burnout of the unit (as a result of a fire) -
with direct power supply from the network it is dangerous to joke.
In short, you need to rely not on the fuse
and not on the protection, but on your own head and not make a short circuit. ;-)
It will save you from a fire...
It’s true that if you make a short circuit, then the voltage for
for some time jumps to 100-200V.
In general, I saw several computers after a short circuit - if at 12V, then
on the screws and cdroms the microcircuits simply exploded, if
at 5V, then on the board altogether the tracks are burned out.
If the short circuit is long, then the fuse will work, and
if something just short-circuits for a short time, then the entire
load can be thrown away.
With respect, Evgeniy.
07 Sep 01 18:22, Igor Turashev -> Konstantyn Kankyev:
[skipped]
KK>> And +12 to +5? My first scorpion worked for ~2 seconds :) :(
IT> Did it really work? Usually the TTL, when about 6V is applied to it, already burns out, but not
IT> doesn’t work at all...
He-he, I once supplied exactly 6 volts to the Speck.
For half an hour it went off without a sound, and then a couple
RUSH and KPshek died.
And that’s it - replaced it, gave +5 and no problems ;)
Aleksandr
AK> Either don’t talk nonsense, or justify it!
Well, he burned me...
KF>> In general, if you shorten it, then when you remove the load
SP> Unfortunately, these are not fables. These are stupid developers and assemblers,
SP> emptying input filters and protection elements.
On the contrary, they are not stupid at all. Think about how much more expensive a computer would cost!
WT>> vice versa. There have already been 4 such computers.
DN> There was such an accident. To my surprise, nothing happened to the VG.
On my speck, somehow the leg where +12 is served was torn off. I shoved all sorts of crap in there - from paper clips to the legs of paper bags. All this constantly
fell off and no wonder - the VG is intact. But somehow +12 without +5 was served and it was all over....
Yuri Nazarenko/Rezident/UninstaLL Team was with you... Her head was braided in long braids.
KF>>> This enemy power supply may one day burn down the Spectrum.
AK>> Either don’t talk nonsense, or justify it!
SP>> Protection has not yet come across in any ATshnom, only in ATX.
DR>>> this is not a reason to invent all sorts of fables
DR>>> and rub them into the gullible population.
SP>> Unfortunately, these are not fables. These are stupid developers and assemblers,
SP>> emptying input filters and protection elements.
KF>> the computer cost!
SP> The power supply itself would have become no more than fifty dollars more expensive, but more reliable!
$50? If a computer costs $300, this is not so little.
Sat 8 Sep 2001 at 10:14:11 Denis Rybakov -> Alexandr Kushnikov on the topic
Power supply
AK>> But the fuse won’t save you?
DR> It’s the fuse that saves extremely rarely, because
DR> it will burn out last of all the ones knocked out in in case
DR> of an accident due to its inertia. Basically, it
DR> is placed there to prevent
DR> complete burnout of the unit (as a result of a fire) -
DR> it is dangerous to joke with direct power supply from the network.
The fuse, as a rule, is placed in the circuit of the primary winding of the transformer.
When increased consumption occurs in the power supply due to a short circuit, the
primary winding may burn out, too. the current flowing through it exceeds the norm. Consequently, a properly designed fuse will save the entire power supply from burning out, but only if the fuse current is less than the current at which the winding burns out and the circuit is designed for a current exceeding the rated one.
This only applies to those power supplies that are made “with a reserve,” that is, competently.
DR> In short, you should not rely on fuse,
DR> and not for protection, but for your own head and do not short circuit. ;-)
This is, of course, first of all ;-)
EP> It will save you from a fire...
EP> It’s true that if you make a short circuit, then the voltage at
EP> for some time jumps to 100-200V.
What does that mean then and for some time? There is Ohm's law: RI=U. This time
is negligibly short.
EP> In general, I saw several computers after a short circuit - if at 12V -
EP> then
EP> on the screws and cdroms the microcircuits simply exploded, if
EP> at 5V - then the tracks on the board were completely burnt out.
I also saw this, though on Spectrums. And this means that the power supply is made with a current reserve, which is actually good, but in this case it is better to have current protection (fuse) immediately after the power supply. Or semiconductor protection (like that
for VG93).
In short, I want to say that all this is due to incorrect calculations.
EP> Now, if the short circuit is long, then the fuse will work, and
""""""""" - ?????
The short circuit is long??? - original.
EP> if something just short-circuits for a short time, then the entire
EP> load can be thrown away.
If this is practical, then yes.
It’s the same as if you push a 100-horsepower engine into a cart. It’s logical?
KF> Well, it burned me...
Well, what can I say? Perhaps you connected something wrong, it is common for everyone to make mistakes.
You understand that both the PC and the Specky use the same voltages: +5, +12;
there are others on the PC, but the Specky rarely uses -5. The current strength will be taken only as much as is necessary. Ohm's law is also the same for everyone.
And in general, why am I telling you all this - you already know this very well.
But what you burn happens. ;-(.
Tue 11 Sep 2001 at 07:33:31 Alexander Seleznev -> Alexandr Kushnikov on the topic
Power supply
KF>>>> This enemy power supply may one day burn down the Spectrum.
AK> Well, what can I say? Perhaps you connected something wrong, making mistakes
AK> is common to everyone.
Yes, I did the short circuit!!!
AK> You understand that both the PC and the Specky use
AK> the same voltages: +5, +12; there are others on the PC; on Specky AK> -5 is rarely used. The current strength will be taken only as much as
AK> is needed. Ohm's law is also the same for everyone.
You see, the PC subject is pulsed and very powerful (compared
to the classic Speck one) and does not yet have protection for output voltage
and current.
AK> What does it mean later and for some time? There is Ohm's law: RI=U. This time
AK> is negligibly small.
Get into the subject:
you close - nothing burns out at all, everything works fine, the wires
get very hot.
you open - all the generated power (and at the moment of the short circuit it was
significantly
more than the consumption of your device) is converted into
voltage
why does this happen - the regulation circuit in the power supply is too
inertial.
That is, you have already eliminated the short circuit, but it reaches the power supply late.
14 Sep 01 19:05, Alexandr Kushnikov wrote to Denis Rybakov:
AK> The fuse is usually placed in the primary winding circuit
AK> of the transformer. When increased
AK> consumption occurs in the power supply due to a short circuit, the primary winding may also burn out, since the current
AK> flowing through it exceeds the norm. Consequently, a properly designed
AK> fuse will save the entire power supply from burnout, but only if
AK> the fuse current is less than the current at which the
AK> winding burns out and the circuit is designed for a current exceeding the rated one. This
AK> applies only to those power supplies that are made “with a reserve”, that is, correctly.
1. There are high-capacity capacitors in the 220-volt circuit, after
the fuse.
2. Transistors burn out earlier.
3. The fuse does not burn out from the current, but from the applied energy per unit
of time.
A piece of wire in the fuse, for it to burn, you also need to heat it up.
4. I didn’t see any burnt fuses...
September 15, 2001 Kirill Frolov wrote to Alexandr Kushnikov about ·Power supply·
KF> 1. There are high-capacity capacitors in the 220 volt circuit, after the
KF> fuse.
In addition to filtering, they are used to create a zero, and they are designed for 150
volts, and in the event of a short circuit on one of them there is much more.
KF> 2. Transistors burn out earlier.
They don’t burn out, but break through, and the breakdown is caused by the base-collector, which leads to
short circuit in the circuit 220.
KF> 3. The fuse does not burn out from the current, but from the applied energy per
KF> unit of time.
KF> A piece of wire in the fuse, in order for it to burn, you also need to heat it up.
After the breakdown of the transistors, the conditions for its combustion are more than favorable..
KF> 4. I didn’t see any blown fuses...
That means I didn’t see cheap power supplies. There, more often than not, the fuse generally blows along with the glass! I saw it myself several times. The reason is above.
SP> In addition to filtration, they are used to create zero, and they are designed
SP> for 150 volts, and in the event of a short circuit on one of them it becomes much more.
Well, finally... And where do you buy this shit? I have very decent 400V, 220MkF capacitors.
Besides, I extremely doubt the fact you described, since theoretically, even in a _not_ emergency situation, the total
voltage on the capacitors can be close to 380V, i.e.
each of them should _at least_ be 200 volts, this the most
extreme case, although in this situation you can only hope
on the Almighty that something is a little warped somewhere.
SP> They don’t burn out, but break through, and the base-collector goes to the breakdown,
SP> which
with a given mode almost instantly causes a breakdown
base-emitter, but this is a very short period of time often
enough to carry out the base circuits as well.
SP> leads to a short circuit in circuit 220.
as a consequence.
SP> After a breakdown of the transistors, the conditions for its combustion are more than
SP> favorable..
Undoubtedly.