Team-BHP - The Home Appliance thread

Quote:

Originally Posted by Thad E Ginathom (Post 3942684)

Then I have the wrong end of the stick, as I thought I had read or been told the opposite.

Solid state electronics have an infinite life. The vacuum tube kind and the ones with filament have a limited life based on factors including the operating conditions.
So the old fashioned Vacuum tube (or what they were called as Valves. Any one saw one ?), Tube lights, incandescent bulbs, CRT and Magnetrons all have a limited life.

Quote:

Originally Posted by vdi (Post 3942516)

Am having issue with the voltage at home and electricity board says nothing can be done now due to some 11KV line problem which won't be solved in the near future.

My electrician suggested for installing a step up and can someone suggest a good one to solve this issue.

Had the same problem at home. Solved it by installing an step up transformer on the mains from http://elnixpowersystems.com/

You can also try other brands.

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Originally Posted by Prowler (Post 3942792)

Anyone seen valves? Not only was I born before the transistor became ubiquitous, and all stuff like radios and TVs glowed, but I'm also a recovering audiophile. So valves? Yeah... :uncontrol

(actually, all my hifi stuff has been solid-state)

Quote:

Originally Posted by Jaguar (Post 3942906)

And these electronic boards are the first ones to conk off :D Talking from my experience with Washing Machine, Refregrator, TV etc.

I know this isn't the language thread, but I keep reading this here, and wanting to say... the English expression is actually conk out, not off. Sorry: it's a weird language!

But yes, I'd agree that infinite somewhat overstates the life of ss electronics!

Quote:

Originally Posted by Jaguar (Post 3942906)

And these electronic boards are the first ones to conk off :D Talking from my experience with Washing Machine, Refregrator, TV etc.

Quote:

Originally Posted by Thad E Ginathom (Post 3943330)

I agree completely with you. BTW you always have the knack of putting things in the right perspective with few words. :) (eg: the quote in bold)

I know that you are an audiophile but recovering audiophile ...

Unfortunately solid state electronics doesn't include only silicon chips. The peripheral components like electrolytics tend to fail early when operating in higher temperatures. Additionally as Jaguar says, the failure rate is higher with components which work with high power.

LED lights may also suffer failures more in the drivers than in the actual LED chips. Bottomline is the life of an electronics board largely depends on how well they are designed. The military grade components are mission critical and operate well over a broader temperature range than the industrial grade types. But the commercial grade components come in the bottom of the pile and have a narrower range.

There is a misconception that solid state electronics have an infinite life span. It's no true. In practice the biggest factor is temperature fluctuations.

Solid state components do come with a finite MTBF and usually a range of environmental criteria for which this MTBF will be valid.

My own experience on car electronics, home appliances and my own industry, telecom, so called electronic failures tend to be not so much the solid state components, but the wiring, the connectors, cracked PCB, water ingress etc etc. So actually pretty mundane electrical/mechanical problem. Although in the public eye they manifest them as electronic problems

Jeroen

Quote:

Solid state components do come with a finite MTBF and usually a range of environmental criteria for which this MTBF will be valid.

It all depends on the Solid state components. The Mean Time Between Failure varies widely depending on the type and the environment. For example: Copleycontrols' published data on one of their boards shows MTBF of 282187 hours or 32.21 years.

For the curious, SeaGate hard drives - at least some models, originally developed for the military have a 300,000 to 1,200,000 hours MTBF for hard disk drive mechanisms, which might lead one to conclude that the specification promises between 30 and 120 years of continuous operation. This is not the case - says their "Hard drive reliability and MTBF/AFR" knowledgebase article.

When I said earlier that Solid state electronics have an 'infinite life' it was meant to be relative. For example, some LED pilot lights in the dashboard assembly of a car last the lifetime of the car. Other things being equal, the chances of a mechanical failure is higher than the chances of an electronics failure.

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Originally Posted by greenhorn (Post 3935654)

what can be done to take care of cooling in a kitchen?
My flat is in a set of snug apartments which don't allow much ventilation

I've installed an exhaust fan, still it gets very hot during cooking

any other solutions ?

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Originally Posted by Thad E Ginathom (Post 3935804)

Extractor fan... Over the cooker, in the form of a chimney. Grab that hot air and expel it before it spreads to the rest of the room. An extractor fan elsewhere in the room will be much less help.

Agree with Thad.
I would suggest you look at some "FUME CUPBOARDS" - at least their design. There is a very good video on YouTube animating the airflows.

I find that the chimney hoods sold are atrociously inadequate and are mere decorative pieces in a kitchen. Unless you take care of funneling the heat and exhaust properly into the chimney, it is unlikely to be of much use.

There is some empirical data on how to design a chimney - The projection of the chimney should be at least one third of the height of the chimney from the cooking surface. The projection is measured from the edge of the burner/flame; so if you have a chimney that is about 30" high off the cooking surface, it should project 10" from the edge of the burner(s) on all sides.

A fume cupboard is a great place to start, as chemistry labs deal with toxic fumes and the design goal is to minimize leakage of these fumes.

Also, did you know - air inside the home is much more polluted than the outside (have not read the actual study and the assumptions)?

Good luck and let us know how you solve the problem. I'm putting a glass box around the stove (or more of a larger funnel, I'll post some pics after it is done - still subject to the carpenter's recommendations and practicalities)

Quote:

Originally Posted by Prowler (Post 3942457)

If you still continue to use incandescent bulbs for whatever purpose, I have a proven technique to extend their useful life for a l-o-n-g time.
I have had a 25 W bulb that served for over 15 years. The trick is to add a silicon diode (1N4007) in series with the bulb. The light output comes down to half of normal level. But the life increases many times. The current consumption is reduced by half too. The only reason the bulb died was because the painters smashed the bulb inadvertently.

Neat!
What wattage is the diode rated for?

I wish to add a potentiometer dimmer to limit the inrush current when the filament is cold. This would be for a 60W or 100W bulb. Could you suggest a suitable rating and brand? The idea is to slowly increase the voltage to the bulb upto max and similarly while switching off slowly reduce the voltage to zero. [Something like those fan regulators that fit within a switch size slot]. Hopefully, this way I can prolong the life of the bulb AND enjoy the nice light from a incandescent (while they are still available!).

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Originally Posted by mvadg (Post 3950200)

You don't need to worry about the momentary surge when you add a diode in series with the incandescent bulb. If you plan to use a 60 W or 100 W bulb you can use a 1N5407 diode. This diode can pass 3 A (surge rating of 200 A) and has a PIV of 800 V.

Just fit it and forget it. :)

Quote:

Originally Posted by Prowler (Post 3944350)

It all depends on the Solid state components. The Mean Time Between Failure varies widely depending on the type and the environment. For example: Copleycontrols' published data on one of their boards shows MTBF of 282187 hours or 32.21 years. .....

When I said earlier that Solid state electronics have an 'infinite life' it was meant to be relative. For example, some LED pilot lights in the dashboard assembly of a car last the lifetime of the car. Other things being equal, the chances of a mechanical failure is higher than the chances of an electronics failure.

SS Devices are far more durable then the older valve type of stuff. Beyond this there is not much more to be said. Failure is more of a random phenomena. Of course bad power in India helps reduce the life.

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Originally Posted by johannskaria (Post 3944494)

Bought a food processor for grandparents Black and Decker PRSM600 800 Watts 20 Function Food Processor from Croma. Never knew these things was so expensive (31K). The last time my grandma bought one was a Braun Food processor , approximately 35 years back!!!

We bought a Kenwood Chef in the UK in 1989. It worked till last year, and I lost it due to failure of one mechanical coupling (of the liquidizer bowl) about 2-1/2 years ago. So got another one (this time 1200W against the 500W earlier) which cost 54k with four accessories. I swapped the sausage stuffer to a steel bowl within the price, since as vegetarians we had no use for it. I expect this one to outlast me in this world.