Switch Mode Power Supplies have at minimum 20 mS hold-up.? In reality they have more, but not necessarily a lot more.

I built a factory control system for the DOE way back when and used an unregulated "Ugly" brand power supply for the 24V.? BIG transformer, BIGGER capacitors.? Worked great.? Cheap (for the time).

Upper right corner of left enclosure


Me working on version 2.? I said it was way back in time, there are dinosaurs outside!

On 10-Feb-25 20:44, Bill in OKC too via groups.io wrote:

In 1986 I was attending an Army Satellite terminal training class? at Ft. Gordon, GA. Had a bad storm that night that shut down our terminal. I'd been writing a letter on the Heathkit. H89 computer when I left for class. Expected it to be shut down when I got back to the dorm. Nope! The filter caps in that power supply were the size of my fists. It was only a transient power hit, but it took down the relatively modern MILSPEC satellite terminal, and didn't touch the monstrous linear old-school linear power supply.?

?

Bill in OKC?

?

William R. Meyers, MSgt, USAF(Ret.)

?

In 1986 I was attending an Army Satellite terminal training class? at Ft. Gordon, GA. Had a bad storm that night that shut down our terminal. I'd been writing a letter on the Heathkit. H89 computer when I left for class. Expected it to be shut down when I got back to the dorm. Nope! The filter caps in that power supply were the size of my fists. It was only a transient power hit, but it took down the relatively modern MILSPEC satellite terminal, and didn't touch the monstrous linear old-school linear power supply.?

Bill in OKC?

William R. Meyers, MSgt, USAF(Ret.)

I wonder how make they make inverter welders so light today.
It was Aluminum winding onsecondary side now they lighter.
Now it is high frequency is about what know.
Dave

I noticed at first the 25 amp breaker.?

That is only 6,000 watts.?

My home is only 100 amp main at 240 center Tap 120 is 24,000 watts.?

?

I have wonder why 50 or 60 Hz .

If up frequency you drop copper needs.? I have seen generators that 400Hz . My guess was for electronics or Radar.?

?Now from chart it has Japan with some island 50hz and other 60 Hz and voltage 100, 120 and 220 volts.?

?

If ship outside of America Grainger had a motor 120 220 and 240 50hz or 60 Hz 56C frame cover most bases was costly but cheaper than shipping motor.

?

Dave?

?

On Sun, Feb 9, 2025 at 07:08 AM, Jerry Durand wrote:

In the UK the power is 240V, 50Hz.? Outlets are often wired in a ring,
not just one linear connection.

Here we have 220V, 50Hz.? On the poles is 3 phase WYE, so 220V from any
leg to the common and 380V from leg to leg.? A typical dacha (small
"country house") is connected to one leg and the common with a 25 amp
breaker and RCD (like a ground fault breaker in the usa). That's all the
power you get.

Because of a series of murky events, we got all 3 phases so have 3 phase
power for the workshop, our sauna, and the greenhouse heater.

Wiring up the milling machine to 380 volts seemed odd, at that voltage
it only has a 5 amp breaker (well, three 5 amp breakers ganged together).

I'm still getting used to how thin wire is here, things use half the
current and with the higher voltage can stand a greater voltage drop,
hence thin wire.

One problem with 50Hz is motors and transformers need 20% more iron in
them, making them bigger and more expensive.? In appliances like washing
machines you'll find brushed motors instead of the induction motors the
usa uses.? Our refrigerator has a tiny brushless DC motor (3 phase with
VFD) as we use propane/butane for refrigerant instead of the
fluorocarbons we had in California.? Propane/butane is more efficient
and much lower pressure so refrigeration gear is pretty low power.

If we were doing power systems over, probably something like 240 Volts
at 100Hz would be good.? It would certainly save a lot of iron and
wasted wattage.? But, at least we're not in the part of Japan where I
hear they have 100 Volts and 50Hz, worst of both worlds.

In the UK the power is 240V, 50Hz.? Outlets are often wired in a ring,
not just one linear connection.

Here we have 220V, 50Hz.? On the poles is 3 phase WYE, so 220V from any
leg to the common and 380V from leg to leg.? A typical dacha (small
"country house") is connected to one leg and the common with a 25 amp
breaker and RCD (like a ground fault breaker in the usa). That's all the
power you get.

Because of a series of murky events, we got all 3 phases so have 3 phase
power for the workshop, our sauna, and the greenhouse heater.

Wiring up the milling machine to 380 volts seemed odd, at that voltage
it only has a 5 amp breaker (well, three 5 amp breakers ganged together).

I'm still getting used to how thin wire is here, things use half the
current and with the higher voltage can stand a greater voltage drop,
hence thin wire.

One problem with 50Hz is motors and transformers need 20% more iron in
them, making them bigger and more expensive.? In appliances like washing
machines you'll find brushed motors instead of the induction motors the
usa uses.? Our refrigerator has a tiny brushless DC motor (3 phase with
VFD) as we use propane/butane for refrigerant instead of the
fluorocarbons we had in California.? Propane/butane is more efficient
and much lower pressure so refrigeration gear is pretty low power.

If we were doing power systems over, probably something like 240 Volts
at 100Hz would be good.? It would certainly save a lot of iron and
wasted wattage.? But, at least we're not in the part of Japan where I
hear they have 100 Volts and 50Hz, worst of both worlds.

I always think home voltage in the UK and about have world home voltage 220 volts in the children bedroom.
From what I understand that 220 to ground. 2 wires off pole. { Back 1920s LA used 220 volt 50 Hz or 120 volt 50 Hz from the stories I been told. }
We use 120 to ground and 3 wires off the pole.
Slowly most countries are switching to 110 or 120 volt for home uses and only a stove and or big ac use 220/240 volts.
Dave

I had one cross reference at time for European, UK , JAPAN,? CHINA & and few other countries. I do not know what happened but found on internet around 1998. But retirement I did think I need that data. I still have on the power used by world and color codes for power.?

?

Dave?