New G2 HP Prime

[Tim Wessman]

Connecting your calculator by USB is one way.

Delete your Documents\HP Prime\Calculators\Prime\testmode.hpsettings file is another.

[Voldemar]

Thank You, Tim.
Both methods works.

[JDW]

What is the DISPLAY REFRESH RATE on the Version C and the new Prime?

I've been taking photos and video of the Prime lately and my eyes can now see the screen refresh pretty clearly, especially when I blink. I of course don't notice that on any of my mobile phones, iPod Touches etc. Is the Prime less than 60Hz? And most importantly, is there a hack to make the refresh higher? :-)

[Tim Wessman]

The issue isn't refresh rate, but that some places don't use off screen buffers for drawing. Specifically, the home screen is one culprit here.

[cyrille de brébisson]

Hello

"Is the Prime less than 60Hz?"

Actually, it is specifically NOT at 60hz, nor at 50hz. G2 is as 55 and I do not remember what G1 is at...

Should it be at 60Hz, since it would not be "exactly" at 60hz, and since a lot of lighting (fluorecent) in the US is at 60Hz, you would get noticeable stroboscopic effects (think backward moving weel sproke in movies type effects)

In europe, 50Hz is use.

So, the calcularots are setup, on purpose to be far away enough from both frequencies.
Frequencies to low (<40Hz) will be visible to the naked eye. higher frequencies waste power...

Hence the 55hz choice.

Cyrille

[JDW]

(09-04-2018 06:35 AM)cyrille de brébisson Wrote:  G2 is as 55 and I do not remember what G1 is at...

Here in Japan we use 50Hz and 60Hz, differing by location. My area is 60Hz.

So either G1 is refreshing at lower than 55Hz or is the "off screen buffer" thing that Tim W. mentioned. I don't see "strobing" when I look at my Version C Prime, but I can tell the screen flickers or otherwise refreshes slowly at times. Again, I don't see this on my iOS device screens so I guess it makes the Prime's refresh more noticeable.

I'm rather surprised I am the only person who has mentioned this. Surely it's not just the 2 Primes that I have.

[Albert Chan]

(09-04-2018 07:03 AM)JDW Wrote:  Here in Japan we use 50Hz and 60Hz, differing by location. My area is 60Hz.

From Google results, you must live in the western part of Japan.

Also noticed voltage is lower than in the states, at 100 volt (they must love the metric system)
Does this mean charging a Prime (or other electronics) is safer ?

Yes, I know the label say 100 to 240 volts, 50/60 Hz, but how "compatible" is it ?
Is there an optimal voltage / frequency even for this type of wide ranged charger ?

[JDW]

(09-04-2018 03:37 PM)Albert Chan Wrote:  From Google results, you must live in the western part of Japan.

I live right in the center of Honshu, the main island of Japan, nearest to Nagoya City. We are 60Hz in this area, and yes at 100VAC. Everything that works in the USA works in my area, at least in my experience.

[Steve Simpkin]

(09-04-2018 07:03 AM)JDW Wrote:  

(09-04-2018 06:35 AM)cyrille de brébisson Wrote:  G2 is as 55 and I do not remember what G1 is at...

Here in Japan we use 50Hz and 60Hz, differing by location. My area is 60Hz.

So either G1 is refreshing at lower than 55Hz or is the "off screen buffer" thing that Tim W. mentioned. I don't see "strobing" when I look at my Version C Prime, but I can tell the screen flickers or otherwise refreshes slowly at times. Again, I don't see this on my iOS device screens so I guess it makes the Prime's refresh more noticeable.

I'm rather surprised I am the only person who has mentioned this. Surely it's not just the 2 Primes that I have.

I don't recall hearing of this "flickering display" issue before. Can you see it when you are outside under natural light?

[JDW]

(09-05-2018 12:19 AM)Steve Simpkin Wrote:  I don't recall hearing of this "flickering display" issue before. Can you see it when you are outside under natural light?

With all the screen glare? Not as easily as indoors or at night, no. But it is still there.

It doesn't flicker badly. My eyes simply notice something odd when I view thin lines on the screen mostly. For example, enable RPN mode then press Home. You should see about 10-levels of the Stack, separated by horizontal lines. Either my eyes are going bad, or those lines wobble up/down! When I put such thin vertical lines on my iPhone 7 (yes, I know it has a high resolution) I get no such wobbling effect.

Okay, I just walked into a room with a diffused window and allowed the light to hit my Prime. The glare makes it much harder to notice the wobble, but it is there. I then walked into a shadow area of a large room with no lights on but lit well enough to see (it's daytime here in Japan now). I still see the wobble. So one cannot blame this in fluorescent lighting.

It's not like the horizontal lines are wobbling all over the screen. It's a very subtle jitter. Look for it. Surely you will see it on your Prime as well.

[cyrille de brébisson]

Hello,

- "US is 100V: They must love the metric system" "Does that mean that it is safer..."

Actually, they are 110V (nominal) and anything from 90V to 120V real! which is a HUGE variation (note, these are voltages that I mesured at my house when I lived in Boise)...
This variation, to me, means that the US electricity infrastructure is carp. It should not have such large swings...

In comparison, the french system is 220V nominal, but oscilate, in reality betweeen 230 and 240V (mesured at my place in the boonies). showing much less variability, but absolute and in percentage.

Is the US system safer? ABSOLUTELY NOT!

First, what kills you is mostly Amps, not volts (you can easely take a multi Kilo volt shock without harm. Thnk of an electrostatic discharge).

Second, if you half the voltage, to get the same power you need to double the amps...
BUT, the energy released through heating in a conductor is RI² (where R is the conductor resistance and I the intensity: Amps)...
As a result, things in the US heat a lot. Use the vacum cleaner (typically 1~1.5KW) and touch the cable, you can feel the heat.
This leads to a large number of house fires, especially in old houses with old wires.

Third, american have access to a WHOLE lot more power than other countries. Building code specified a minimum of 200A, at 220V, comming in the house (but a lot of house have more, 300 or 400A). In France you can choose between 15, 30 and 45A (at 220V also). This means you have, potentially, 4.5 times more power to kill yourself, should you do something dumb.

On the other hand, I love the US electrical boxes with their build in back planes and clip on fuses. I hope that they adopt this in other countries!

Cyrille

[Albert Chan]

Hi, cyrille de brébisson,

You mis-read my post. Japan is 100V, which is lower than the states.
Brown-out voltage of 90V is not common, at least where I live (Massachusetts).
This is a drastic measure for avoiding total black out ...

I would say 115V +/- 5% is more typical.

Quote:Is the US system safer? ABSOLUTELY NOT! First, what kills you is mostly Amps, not volts ...

With higher volts, more Amps passing thru the body ... I think high voltage is more dangerous.

Why does US/UK use 110/120V and others use 220/240V

You can also deduce it this way.
Most US home already have 220/240V available.
Why do we tap the neutral, sent 110/120V to the wall outlet ?

[grsbanks]

(09-05-2018 12:52 PM)Albert Chan Wrote:  

Quote:Is the US system safer? ABSOLUTELY NOT! First, what kills you is mostly Amps, not volts ...

With higher volts, more Amps passing thru the body ... I think high voltage is more dangerous.

It's not amps passing through the body that you need to worry about. Both 110V and 220V are potentially lethal. Neither one is safer than the other in that respect.

The point Cyrille was making was the current going through mains-powered appliances and the cables connecting them to the mains. For the same power consumption you have double the number of amps going through them, which means 4x the heat being generated by Joule effect, hence the higher fire risk.

Why do you think high power machinery is powered by a tri-phase supply?

(09-05-2018 12:52 PM)Albert Chan Wrote:  Why does US/UK use 110/120V and others use 220/240V

The UK most definitely does not use 110/120V. We use 240V over here.

[Albert Chan]

(09-05-2018 12:59 PM)grsbanks Wrote:  It's not amps passing through the body that you need to worry about. Both 110V and 220V are potentially lethal.
Neither one is safer than the other in that respect.

I had been shocked at work (480/277/240 volts), and at home (120V).
Believe me, 120V, although still potentially lethal, is much safer.

BTW, electricians had a special tool gripping method to reduce chance of death by electrocution.
Essentially, you think of what happened if accidentally shocked, and grip tool accordingly.

If possible, work one handed, to reduce chance of completing the circuit

I agree with you regarding higher fire risk.
What is safer for the body (electrical shock) is worse for the wires (Joule effect).
But, I guess electrical code will take that into consideration. Just look at Japan.

Quote:The UK most definitely does not use 110/120V. We use 240V over here.

Yes, I believe the author made an error on that. Good catch.
A lot of comments also refuted his assertion of "others" using 220V/240V.
I actually learn more from the comments section ...

[CyberAngel]

(09-05-2018 01:57 PM)Albert Chan Wrote:  

(09-05-2018 12:59 PM)grsbanks Wrote:  It's not amps passing through the body that you need to worry about. Both 110V and 220V are potentially lethal.
Neither one is safer than the other in that respect.

I had been shocked at work (480/277/240 volts), and at home (120V).
Believe me, 120V, although still potentially lethal, is much safer.

BTW, electricians had a special tool gripping method to reduce chance of death by electrocution.
Essentially, you think of what happened if accidentally shocked, and grip tool accordingly.

If possible, work one handed, to reduce chance of completing the circuit

I agree with you regarding higher fire risk.
What is safer for the body (electrical shock) is worse for the wires (Joule effect).
But, I guess electrical code will take that into consideration. Just look at Japan.

Quote:The UK most definitely does not use 110/120V. We use 240V over here.

Yes, I believe the author made an error on that. Good catch.
A lot of comments also refuted his assertion of "others" using 220V/240V.
I actually learn more from the comments section ...

One hand grip
got to remember that
The old 220V or so isn't that dangerous, just painful
unless of course the current goes off course through heart
or less important... the brains
- - -
I guess the main current found a better conductor - maybe my skin was sweaty
Pick good luck or God's provision, but I'm still alive!

[ijabbott]

(09-05-2018 12:59 PM)grsbanks Wrote:  

(09-05-2018 12:52 PM)Albert Chan Wrote:  Why does US/UK use 110/120V and others use 220/240V

The UK most definitely does not use 110/120V. We use 240V over here.

Another unusual aspect in the UK is the use of ring mains, so the current from the distribution panel to the outlet is split over over two arcs of a ring (although the current in each arc will depend on the relative lengths of each arc - think parallel resistors).

[cyrille de brébisson]

Hello,

Actually, the history of the UK "40A Rings" with fused power connectors is prety interesting and a cool design... But I have never spent much time thinking about the drawbacks of the system

Cyrille

[JDW]

(09-05-2018 05:12 AM)cyrille de brébisson Wrote:  In France you can choose between 15, 30 and 45A (at 220V also).

Consider yourself lucky. Here in Japan, the main breaker in most homes is largely the same as most apartments, which is either 40A or 60A at 100VAC! Suffice it to say, when you have the A/C on in more than one room, with lights and an oven going and then you decide to vacuum too, there goes the breaker! It's pretty crazy how restrictive they are here. And if you want to swap out that breaker box for a 100A version, you have to pay higher monthly rates! Total insanity. Be thankful for what you have there in Western countries!

[Guenter Schink]

(09-05-2018 05:12 AM)cyrille de brébisson Wrote:  In comparison, the french system is 220V nominal, but oscilate, in reality betweeen 230 and 240V (mesured at my place in the boonies). showing much less variability, but absolute and in percentage.

Cyrille

Small correction. The French system is 230V nominal. It used to be 220V some decades ago.

Günter

[CyberAngel]

(09-07-2018 08:01 PM)Guenter Schink Wrote:  

(09-05-2018 05:12 AM)cyrille de brébisson Wrote:  In comparison, the french system is 220V nominal, but oscilate, in reality betweeen 230 and 240V (mesured at my place in the boonies). showing much less variability, but absolute and in percentage.

Cyrille

Small correction. The French system is 230V nominal. It used to be 220V some decades ago.

Günter

UK was 240V, rest of the EU 220V => 230V everywhere in the EU
Right?