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Re: 0870 Phone Numbers
Don’t think anybody was having a go at UKWG Ken even if it did make something off it – like Roly16 says the service is free anyway. 🙂
But virtually every business that you phone nowadays has one of these numbers and usually after you have got past the interminable menu system they keep you waiting in a queue for ages. 😥
When you consider that 0870 numbers can be charged up to 10p / min somebody is making a lot of easy cash, dear me you can call Australia nowadays for 3p / min through a firm like First number.
What I cannot understand is how it is possible for them to do this without giving prior warning to the caller of the cost, as they have to do with other numbers. eg. TV quizes etc.
Re: 0870 Phone Numbers
Nice one Geoff!
Another case of the internet returning a little bit of power back into the hands of the people.
The reason that firms get away with things like this is that they know that we are all individuals (divided we fall).
Many do not even know how much these calls can cost.
If we all send an email to each of our friends / relatives to publicise this site and they do the same and add their numbers then 0870 might just die eventually. What a good 💡
Andy
Re: Merloni error codes
It has occured to me that the F10 code (Pressure switch not sensing correctly) may signify the operation of the pressure s/w flood level as this seems the only possibility left with regard to the P.switch. ❓
Andy
PS The only way to really check these out without help from Mr Merloni is to use a sort of reverse engineering technique and simulate these faults on a known OK machine, eg by detaching wires, using manual control of the pressure s/w etc. and see what fault occurs. I have tried this on older machines but few of the fault codes seemed to be implemented on these. Up to now I have not had an opportunity with the newer machines.
Maybe someone else could ?
Re: Hpt DF62 d/w
Chris
I have sorted the problem on my machine (DF54). There was a crack in the side of the bottom spray arm (not easy too see). Obviously as it rotated water was squirting out of this crack against the bottom of the door and the surge was enough to overflow the sill. I don’t know how significant this is re: the recuring problems with these machines but it sorted the problem for me and I have not seen it posted elsewhere.
Hope this helps you.
Andy
Re: Hpt DF62 d/w
Chris
I have just put a door seal on a DF54 with the same problem – slowed it down a bit but still dripping at the corners.
Door seal kit- £29.80 inc VAT – (a length of rubber/neoprene/whatever) and two pieces of plastic – robbing sods.
What now? – I hate dishwashers.
Andy
Re: LG WTR1071TP
machineman – Don’t know anything specifically about these machines but spinning during wash is usually due to a loss of motor control by the electronics. This is often due to a short circuit triac on the control module but it could also be failure of feedback from the tacho (if there is one – depends on the type of motor used). Check that the tacho coil is not o/c and that the magnet is fitted and is secure.
Andy
Re: Washing machine, Not letting conditioner drain….
What make of machine is it?
Why?
Because some machines rather than use another valve for the fab con have a device fitted to the top of the soap dispenser to divert rinse water into the fab con dispenser. This is operated mechanically by means of a lever attached to a cam follower / cam on the timer shaft.
Sometimes these can become stiff due to a build up of powder / cr@p on the top of the dispenser. Also the return spring may be unattached or broken.
Andy
Sorry David I did’nt notice your real name on the previous post.
The statement that I could’nt agree with was:-
dpm wrote:So in a brush motor run on AC you can “chop” the top and bottom off the sinewave to alter it’s effective voltage and control the speed
In this you refered to removing the top and bottom of the sinewave ie. decreasing the amplitude or voltage. In actual fact phase angle control is time slicing the signal and does not necessarily decrease the voltage. Consider a case where the pulse is applied at 90deg and 270deg of the cycle. On both half cycles the signal commences at full amplitude (-ve & +ve) and decreases to 0V passing current only during this period. The actual power delivered is therefore approx halved.
I noted with interest your comments on the new 3 phase motor. Jimboxxx has also commented on this in another post. I would be really interested to learn more of this if yourself or anybody has any info.
Regards Andy
Re: Speed control
dpm – Whilst it might be possible to control a ‘brush’ motor in the way that you say this is not how it is done on the vast majority of washing machines.
In the case of a series wound AC motor (using brushes) as found on most washing machines control is achieved by varying the amount of current available to the motor. This is done by employing a triac in series with the field coil and armature. The full mains voltage can be found across this circuit. Control of the triac and thus the motor current is achieved by electronic means.
A triac is effectivly two silicon controlled rectifiers (SCR’s) fabricated back to back on a single chip sharing a common trigger connection (the gate) two other connections MT1 (main terminal 1) and MT2 are across which we deploy the load, in our case the motor. The reason two scr’s are used in this manner is so that both polarities of the phase can pass through the device and thus make full power available. With no signal applied to the gate connection, no current passes through the circuit, but when a pulse signal is applied to the gate the triac will ‘fire’ and allow maximum current (dependant on the reactance / resistance of the load) to flow. Once the triac begins to pass current it will continue to do so until the voltage across it is reduced to a certain level. In the case of our AC supply this occurs as the half wave (eg + transition) passes through the 0V level, at this point the triac will switch off and cease to conduct.As the cycle commences into the – half wave the triac needs to be fired again in order to allow current to flow again. So two pulses are needed for each complete cycle.
The secret to controlling the motor speed in this manner is to vary the point at which we apply this gate pulse relative to the angle of the phase. In most cases this is achieved by the use of a dedicated motor controller IC such as the TDA1085 which was used on many speed control modules, although the earlier modules eg. Hotpoint did use discrete componants only. The timing for the gate pulse is usually derived from sampling the mains frequency, processing this sine wave into a suitable pulse signal and then by delaying this pulse to fire the triac at a suitable angle of the phase. Obviously the later the pulse, the further the phase progression and so less current is allowed to pass.
As Kenny rightly states feedback from the motor tacho is passed to this control circuit to inform the electronics how fast the motor is rotating. This signal was nearly always analogue ie. the amplitude increased relative to the increased speed of the motor, (although the TDA1085 could also utilise a digital signal). The received tacho signal is processed and its value compared to a preset value derived from an external resistor network. Each element of this resistor network corresponds to a selected motor speed / ramp and is switched into use by the timer, relative to the progression of the wash cycle ie. wash, distribute and various spin speeds. With this feedback the control circuit is able to monitor the motor speed and adjust its output to the triac in response. By adding a variable resistance into the network element motor speed control can be adjusted by the user ie. variable spin control.
Most tacho generators nowadays are digital, that is the signal that they output is in the form of pulses. The reason for this is that with the advent of timers / modules that use a microcontroller IC it is much easier to count the number of pulses in a given period than to convert an analogue signal into a form that could be usefull. (eg. analogue to digital conversion)
This type of motor speed / ramp control has also been used with induction motors. The original Bendix induction motors did not have any control at all and were a little violent sometimes when entering the spin mode. Bendix later introduced the models with the small module. These only had two selectable speeds but the main advantage was that this also enabled the current to be gradually increased (ramp) into its full spin speed, rather than a sudden switching of current to the motor.
Andy
Re: Technical Trainers
Thanks for the replies gentlemen – now I understand.
The only question I have is, why you feel it necessary to have to deliver this training ‘in person’ so to speak.
Would it not be easier to make these ‘modules’ available online through this web site? maybe as downloadable PDF’s.
Certainly save you a lot of hassle especially as you are not making any charge for this service.
“Cost to the guys = the time to listen” – (Or do you intend to charge the businesses that employ engineers?)
It sounds like a brilliant idea. But a lot of hard work for someone compliling these modules.
Andy
Re: Amusing Anecdotes & Other Tales
Martin
I was only explaining how the customers appreciate my promptness attending the job, and thank me for that.
Also how my wife responds when they complement me on the phone!
Funny………………………. I never could understand why she answers them in the way that she does.
Mmmmmh!
Andy
Re: Amusing Anecdotes & Other Tales
andy2 wrote:To which my wife always replys……………………..
a) “Don’t I know it!
b) “You’re not wrong there”
c) “Tell me about it”
d) “It been a problem for years”
e) “His mother says his father had the same problem”
f) “He’s improving as he get older.
g) “Never noticed, i’me usually asleep by then.
h) “Ar’nt you the lucky one then”!
I) “Wait until I get my hand on him”No prizes but which is the right answer?
(Is this getting off topic?)
