That's assuming the time switch uses a mains voltage synchronous motor. A fact you did not at any time say. Neither did you specify the motor current so how the hell could I or anyone else work out the maximum load imposed ?

Basically you quoted a power consumption with no other details as to how you came by the figure mentioning only a multimeter.

I would love to know how you arrived at the number you quoted, suspect it came out of the same place as your other facetious remarks.

None of the multimeters I have seen have a capability to measure phase dfference angle between voltage and current and in any case with such a small device a straightforward conversion would be more than accurate enough.

In any case a proper synchronous motor (just like an alternator) can be made to operate at any power factor simply by varying it's field excitation.

Do you have any links to a motorised timer that uses any other sort of motor?

Or even any sensible reason why anyone would use anything else for this particular application?


Why are you talking about 'maximum load'?

We were discussing power consumption.


Think laterally, Graham.

I was interesting in the approximate Power Consumption.

You can assume that I didn't use an oscilloscope but did use something else (that has been mentioned on this forum from time to time).


Same here.


So, what was the purpose of your question and why could you not, making that assumption about accuracy, and knowing the UK mains voltage, work out the current?


'Can be'?

I would consider it to be extremely sloppy experimental practice to assume a cheap timer is made in a certain way just because it 'can be'.

I'm not a fan of screens mounted over the fireplace - i don't find it comfortable watching a screen high up, even if it's tilted. Screens are much better at the same sort of level you'd have a pc monitor - with the top at about eye level when seated.

I'd not realised you were looking at a screen that small - certainly no Plasma's at that size. My screen in in a corner and i managed to get a 42" screen (with a narrow bezel and bottom mounted speakers) in the same space as a 32" Sony CRT (and it's pushed further back)

By maximum load I simply meant that the greatest load that could be imposed by any given current which you clearly did not want to specify. Given the load you have the energy consumption

Frankly I don't believe you measured anything at all just expected everyone to accept your figures.

A typical geared sychronous motor as used to drive timers would normally have a consumption of several watts.

A typical such device is here using 4 watts

http://www.hansen-motor.com/hyst-round2hole.php

An electric motor with a rating of just 1mW might just about turn a balanced tiny load of say an electric clock to suggest that a motor with such a tiny power could produce the torque required to turn a rotary switch timing device is ludicrous. This equates to 0.0000013 horsepower. Unless you tell us all how you got to this ridicolous number. I suggest you put up or shut up before you make yourself look even more stupid.

I don't understand your comment about synchronous motor power factors. Are you saying this is not correct ?

This site gives the typical power consumption of a mechanical timer as 2 watts thats 2000 times more than your timer.

http://www.cryer.co.uk/brian/misc/ho...lectricity.htm

You asked for the motor current which I did not measure.


Given the energy consumption and voltage you have the current (assuming PF 1) which is why your original question seemed so stupid.


You just lack the imagination to think around the problem.


ROFLMAO.

That motor is almost as big as the entire switch.


No Graham.

It can easily operate a large electric clock with a second hand.

These timers are not like old washing machine timers. The one I measured was not much larger than a 13a plug and weighs just a few ounces.

Unlike the clock it only has to turn a few grams of plastic once every 24 hours rather than the second hand 1440 times each 24 hours.


You do understand gearing, I suppose?


Actually, I fear it's you who is making yourself look stupid.

You've obviously never measured the current draw of an electric clock.

It seems to have escaped your notice that if a mains timer really did use 4 watts it would run noticeably warm.

You quote a (correct) figure for horsepower but have clearly made no attempt whatsoever to relate that to the work that actually needs to be done:

Clue: You can rotate the timer dial in under half a second with virtually no effort.

The motor has 24 hours to do that much work.

Exercising comfortably (producing way more power than required to turn the dial) a normal male can output around 80w - very roughly 1/10th hp.

So do the sums yourself.


I'm saying that I measured the actual power consumption without making any assumptions about how the timer worked.

As you clearly lack the imagination to work this out for yourself (and yet still accuse other people of looking stupid ):

I measured the power consumption by using a UPS and measured the change in current draw from the battery when the timer was connected.

Very simple and gets you the actual power consumption without knowing anything about the internals of the timer.

Why didn't you just ask in a straightforward manner how I made the measurement in the first place rather than being sly and then getting snarky?

You still say then that a power consumption 2000 times smaller than the average motor driven time switch is realistic. I think not

Graham - I wouldn't waste your time on this Tern is always right and always insists on the last word anyway

Out of interest I just used a electronic multimeter to read the current taken by a small mechanical time switch. It's 3mA at 240V thats 0.72VA. To make that into 1mW would require the pf to be 0.0014. ie virtually a 100% inductive load having almost no resistance. Calculating this works out as a resitive component of the impedance as 1Kohm (from Watts = I squared R). The actual DC resistance of the clock winding comes out at 400Kohm. Connecting 400Kohm across 240V gives 0.6mA. Using this very crude method gives an estimate of the power factor as about 0.2. At 0.2pf the above time switch will have a load of about 144mW ie roughly 150 times the figure of 1mW.

There is no way Hose

You have no idea what the power consumption of a present day timer switch is. The figure you are coming up with is based on guesswork, the power consumption of a motor that is way, way, overpowered for the task and a random web page that you've come up with that comes up with a vague figure of "2 watts (or less)".

I measured it. Carefully.

You have not come up with any convincing answer as to why:

a) It runs dead cold.
b) A motor that rotates a small piece of plastic once in 24 hours should need 4000 times more energy than a clock that rotates a second hand once a minute.
c) Why, when I implicitly agreed with you (as far as the Foxsat was concerned) in post #31 I would then make up a figure that proves that both you and I were way out.


In all honesty you are just annoyed because the statement you made to Andrue was wrong and you don't want to admit it.

I set out to prove that you and I were correct in what we had said to Andrue.

I discovered that we were wrong.

I honestly posted that information.

Without making a proper measurement (you've only come up with a guesstimate) you are disputing the PC of something you've never even seen, let alone handled and measured.

Of course, it's always possible that I made a mistake in the reading and I notice that your guesstimate is smaller by a factor of 27 than the 4 watts you originally stated was a typical power usage.

I said 2 watts which if you search the net is typical of the few of such devices that actually quote this in the spec. A few claim power consumption of around 1.5W. What ever, it made a clear nonsense of your claim to to 1mW which by any stretch of imagination is totally wrong and which a little research would have revealed.

The first time you mentuioned a figure it was this: "A typical such device is here using 4 watts"


Despite your guestimate of 144mw you are still sticking to a figure over ten times that as typical.

I can understand why you don't want to believe my figure but why you don't believe the evidence of your own eyes is a bit of a mystery.

And you still haven't explained why you believe a device turning a small piece of plastic once every 24 hours requires hundreds of times more power than a device that turns a second hand once a minute.

Nor, how something using even the lower figure of 1.5w can run continuously, dead cold.

A standard RED LED takes 10mA (the reccomended current) at 5V, you do the maths.

A figure of 1mW is completely ludicrous

We are discussing a timer, not a red LED.


I'm sorry, Graham.

Just repeating the mantra "It's ludicrous' won't make you right.

A clock can move a second hand around 1440 times a day and run for over a year at around 1.5v on a 2000ma battery.

That means it's using a maximum of .34mw/hr to do 1440 rotations a day.

Now, I'm sure it will take more effort to rotate the timer drum than the second hand but using 1mw gives it over 4000 times the power per revolution to do the job.

I can't help the reading I got from my timer and, given the above it doesn't seem even the slightest bit improbable.

You need to free yourself from your preconceptions. It's quite obvious that the makers of this very little cheap timer have used some quite different means to achieve what they are doing than the makers of the timers you are used to.

Other instances of these devices I've seen in the past have been a lot heavier, for example.

Just accept the fact that technology moves on. People have probably made timers of this sort the same way for many, many, decades and I dare say the Chinese company who made my timer were looking to save manufacturing costs by using a different method, more akin to wall clock mechanism than the timers you're used to. As a result they happen to have reduced the power consumption dramatically.

Before you just repeat the same old: "I've looked it up, mine uses more" mantra, try and ask yourself why you are so stubbornly convinced that all timers will be made the same way forever and why you resolutely believe that a timer must use (using your 1.5w figure) six million times more power to make a rotation than a simple clock.

That is the position that is truly ludicrous.

I give up even an electronic one with absolutely no moving parts needs more energy than that. You could get that sort of power out of a cheap solar cell there's no way it's going to turn your timer.

And yet a fraction of the power easily rotates the second had of a clock 1440 times more often every 24 hours.

I think you are correct to give up.

Unless you can explain why you stubbornly stick to the belief (without ever having seen or examined it), that a timer switch must use six million times more power than a clock you are, as they say, 'p***ing in the wind'.

That's an enormous figure to justify and you haven't been able to make even the slightest attempt to do so. All you are really saying is that you have no idea how the thing actually works.

As you well know the clock you describe does not use a motor at all in the conventional sense but a quartz oscillator driving an impulse device.

I will set you a challenge I have looked at all the manufacturers websites who make small sychronous motors for timers and clocks. So far the smallest power input I have found is 1W. So quite where the maker of your timer sourced the motors is beyond me. Find me a link to such a motor that only uses say 10mW and I might believe you. Otherwise forget it.

Has it not occurred to you that perhaps the timer uses a similar technique?

I'm certainly not making any dogmatic statement about the way it works.

All I did was measure the power consumption. I didn't take the thing apart. (I couldn't - it's sealed).

I told you way back that you need to think outside the envelope you are stuck in. If it's impossible for the timer to be using one sort of motor then it's evidently using another. It's that simple.

Stop making unwarranted assumptions and using them to be so unshakably dogmatic.

That's even more ridiculous quartz technology would not have the torgue to do this nor would it be economic. We are now going into fantasy land from cheap mass produced synchronous motor driven timers to solid state ones and now one that only you have access too. Absolute tripe

So you can buy a cheap quartz clock for a pound but it would be uneconomic to put the same mechanism in a timer?

Come on, Graham, you really are clutching at straws now.

Those clock motors can accelerate an eight inch second hand to rotate it through 6 degrees every single second on, at most, 0.34mw.

Of course there is enough torque to rotate a 1.5"plastic drum the some amount with 6000 times the power available.


The only place we are going is one where a company (perhaps) uses an extremely cheap and extremely common technology in a product in a way that you, personally, are unaware and you are trying to save face by bombastically asserting that they can't do it.

For goodness sake, get over yourself.


Just because I happened to buy something that you don't understand does not, by any stretch of the imagination, mean that only I have access to it. I'll bet tens of thousands of people have them.

Just accept that you've made a complete fool of yourself by making ridiculous assumptions and that, whilst you may have knowledge of electricity supply that does not mean you know about the manufacturing technologies of every electrical product under the sun.

That is just an ad hominem attack on another forum member.

It's quite clear that the discussion here today has been formed with Graham and myself making alternate posts so the assertion that only one party 'must have the last word' and 'is always right' is plainly ridiculous.

You've posted twice to this thread and have said absolutely nothing of relevance to the subject under discussion, merely carrying on a personal vendetta that you seem to have.

Heh, well I never intended to start a fight

I just took two timers round to a friend with a cheapo power meter (one of those with a 13a socket/plug). It reports 0.4w for the electronic one (the one I use for most things) and 1.2w for a 7day mechanical that we use for a landing light.

Of course the accuracy of that meter is dubious but it reported 39w for a table lamp with a 40w bulb. I think we can safely conclude that mechanical timers need a lot more power than electronic ones. It's fascinating to compare the consumption with the Humax HDR.

OK folks lets consider the evidence

I do love a good discussion

1 Tern has a mechanical timer that presumably has the usual way of selecting on and off times. Either by way of way sticking in little pegs or moving a plastic toggle in or out to select on and off times

2 Firstly he decides that it's run by by a commonly available synchronous motor that derives it's time keeping from the mains frequency. I have no problem with this thanks to the excellent way in which my ex colleagues at National Grid despatch generation output instructions to ensure electric time stays within statutory limits of real time. There are millions of such devices in common use, starting even from the first CRT TV's that used the first TV's that used the mains frequency to generate the field scan.

3 Then he decides that a a device that uses over 1W must get warm. Why a synchronous motor operates with an efficency somewhere in the mid 90%'s. Only a tiny proportion of it's energy is wasted in heat the rest is converted into mechanical energy. Only a transformer with an efficiency of about 99% approaches this.

4 When asked to produce evidence that the millions of mechanical timers in use in the world use motors of around 1W or greater in power consumption, we now have a miracle a new previuosly unheard of device that can produce the power of a 1 watt 90% plus efficient motor using only one thousand'th of the energy. Amazingly we now have another pretender to the something for nothing brigade a machine with an efficiency of more than 100%.

Perhaps he would like to submit this amazing device for independent corroboration.

I am sorry if my previous post came across as an attack on another forum member. This was not my intention. My comments were meant as a statement of fact based on my observations of many previous posts. It is just my observation and opinion that Tern always insists on the last word on everything.


Well I don't know anything about this subject so I can't really add anything of value (does this mean I am not allowed to comment on the thread?). Cearly it seem you just want to get my other comments censured. I thought you might have tougher skin and not be so sensitive

Agreed.


Yes, I initially assumed, as did you, that the device was using a synchronous motor as it is sealed and therefore a black box.

When it became obvious that it could not possibly do that with the power consumption I recorded it also became obvious that they were doing it some other way.

This is where we part company because you have taken the blinkered view that there's only one way to make a mechanical timer.


Thermodynamics not your strong suit, eh, Graham?

Where do you propose that this mechanical energy is going if it is not ending up as heat?

To be precise, which form of energy; electrical, potential, chemical, etc, do you believe that the rotational energy has been converted to in order that it has not been converted into heat?

(I remind you of your 'mechanical equivalent of heat' lessons.)

And you did originally state that four watts was the typical usage.


This is unadulterated nonsense.

Virtually every house in the country contains at least one example of such a motor (using the term to mean any device that can convert electrical energy into rotational motion).

It's called a clock and using a maximum of 0.3mw a day it can rotate the second hand 1440 times.

My timer appears to use 3 times that power to move a small plastic drum once.


There is nothing in the least amazing about the device.

They've clearly just found a way to make a timer very cheaply and that method just happens to be much more efficient that the previous method used.

Nothing strange or unusual about that.

Until recently no one would have even considered a 1-2 watt usage of the slightest significance so there would have been zero reason for anyone to even try and research a way of making a more efficient one. I'm pretty sure that the efficiency of mine is a byproduct of a desire to reduce cost rather than any attempt to make it more efficient.

---

Here is a little calculation that demonstrates the utter ludicrousness of the position that you need to use even a single watt to power such a timer.

1 hp ~= 750 watts
1 hp = 33,000 ft/lb per minute
therefore 1w = 44 ft/lb per minute

there are 1440 minutes in a day so using 1 watt for a day would be 63360 ft/lb.

That's equivalent to lifting a ten stone man almost to the top of the Telecom (Post Office) Tower. (Obviously in reality there would be losses but you get the idea.)

This is what Graham is maintaining is necessary to turn a small piece of plastic one rotation in 24 hours.