Knowing the mains voltage is mandatory.
I'll bet Uli Behringer didn't expect my mains to be regularly 255v when he specified a toroid transformer with 230V primary rating...and failed.
Dan.
This is the situation in Holland
The total variance is thus about 60V!
P.s. From http://nl.wikipedia.org/wiki/Lichtnet
P.s. See also http://www.ecoca.ro/ntponeusvro/en50160.pdf
The total variance is thus about 60V!
P.s. From http://nl.wikipedia.org/wiki/Lichtnet
P.s. See also http://www.ecoca.ro/ntponeusvro/en50160.pdf
If you want something nice and precise, try this: International Committee for Information Technology Standards - Wikipedia, the free encyclopedia
Here we can not be more precise then NEN-EN 50160, that is the norm/standard here in Holland (The Netherlands).
+10% has to be expected. How do the BIG-boys (Sony, Pioneer, ...) handle that, they ask the customer what the local line voltage is? I do not think so.
I'm sure they do there quality assessment's before shipping the first one. Especially on the line-voltage compartment.
The world voltages and the tolerances are well published and well known, all this seams a bit of a joke I would hope....as I said earlier commercial equipment is designed to take this into account, its a part of the design cycle. Non of this is new and it worries me that it suddenly seems to have been discovered on this thread that mains voltages vary!
For anyone in Europe here is a little something regarding the voltage harmonisation (only from 1994 so it may be a little new for some) that explains why there is such a wide voltage spread in Europe....
For anyone in Europe here is a little something regarding the voltage harmonisation (only from 1994 so it may be a little new for some) that explains why there is such a wide voltage spread in Europe....
Sitting at my computer working on a product design and getting quotations for in the range of 100K parts I can't imagine that a major manufacturer is not having to do the same thing. Now to order say 100K transformers to get your price point I surely wouldn't be waiting for my warranty department to report back that the specified transformers are now failing in the field due to underrating that item. What a disaster that would be, having to replace those units and being contractually responsible to take delivery of those parts that are wrongly specified. If you know the acceptable range of power output is +/- 15% any engineer worth there pay is going to specify at least a minimum range that is wider than that as a safety factor. I don't know any mechanical engineers who would ever use a minimum value variation as a final specification, that would be criminal in most instances, I would expect an EE would be trained to think the same way? How is this taught in schools, what is an acceptable safety margin when designing a power supply?
Depends on the cost of the final product, the overall budget for the design and its final build price, but also reputation reliability and safety play a part. But then a lot of products use SMPSs which allow for a greater voltage range, and for worldwide marketing a supply that can cope with all expected voltages is advantages as you don't have to keep different line of stock for different regions. There are many solutions and methods used, but as said tolerance is taken into account for all aspects of the design....
Marce,
I would tend to agree with you there are variables in all of this and price point is a definite factor in all designs. Now quality and reliability is a very strong indicator of a good design and a manufacturers reputation can depend on these factors once a product hits the market. Now I would never purchase say an electronic item branded with the Walmart brand, they are substandard at best, are very likely to fail or be DOA when first turned on, that is the type of cost point that they are designed for. Are companies really that stupid today, everything is now on the internet for those to find who want to know. Nothing like ruining your own business by being known for producing failure prone products. Look at what saving a few cents has cost GM for the stupid ignition switch in millions of cars, I have one that needs that exact switch replaced by recall. Not a good way to get repeat customers.
I would tend to agree with you there are variables in all of this and price point is a definite factor in all designs. Now quality and reliability is a very strong indicator of a good design and a manufacturers reputation can depend on these factors once a product hits the market. Now I would never purchase say an electronic item branded with the Walmart brand, they are substandard at best, are very likely to fail or be DOA when first turned on, that is the type of cost point that they are designed for. Are companies really that stupid today, everything is now on the internet for those to find who want to know. Nothing like ruining your own business by being known for producing failure prone products. Look at what saving a few cents has cost GM for the stupid ignition switch in millions of cars, I have one that needs that exact switch replaced by recall. Not a good way to get repeat customers.
hi
1. Where can i find CTC specification ?
2. CTC has 1k output impedance in balanced or single-ended mode ?
3. CTC is built on jfet+mosfet or jfet+bjt ?
In se input and bal output I have 0.03 THD (2sk246/2sj103 + bjt, 1-3V output), is this not so good ?
Square wave response on 200kHZ is really nice
1. Where can i find CTC specification ?
2. CTC has 1k output impedance in balanced or single-ended mode ?
3. CTC is built on jfet+mosfet or jfet+bjt ?
In se input and bal output I have 0.03 THD (2sk246/2sj103 + bjt, 1-3V output), is this not so good ?
Square wave response on 200kHZ is really nice
Bean there and seen that, a saving of a few pence cost a company I worked for a million pounds...
Companies aren't that stupid, but what you do get is over zealous sycophantic management types who like to grease higher management, and the silly decisions are often made at that level, despite the screaming warnings from the engineering group.
To be fair most supplies are SMPS these days so it is a little easier...
Now when I was a lad I can remember the switch or jumper on the back of gear for 120V/240V operation, getting it wrong could be interesting
Now when I was a lad I can remember the switch or jumper on the back of gear for 120V/240V operation, getting it wrong could be interesting
A 25% probability of interestingness
I've heard it said that any organization with over 100 employees is functionally insane. This agrees with my experience, also.
Last edited:
The Crowd In Peace And War - Gustav Le Bon
Interesting book from many years ago, although it contains some presently strange opinions that would have been common in that time period. It talks about how crowds are formed, how they behave, how many people it takes to form a crowd, etc...
Also coincidentally 1/20 is 5% which is close to the prevalence of psychopathy (Robert Hare, Martha Stout, etc...) in the general population depending on which research you're reading, which tends to be a common factor in the downfall of many organizations.
- Status
- Not open for further replies.