We are spoiled in the UK: typically 235V varing by around +-2%, but some domestic wiring, which does not conform the the regulations, gives large voltage drops at the wall socket.
Also, the mains plugs and sockets vary a lot in quality, not to mention the workmanship of the connections. It is common to find live and neutral swapped and the earth terminal screw not tightened sufficiently. Our wall sockes are rated at 13A but many are only good for around 5A. You often find plugs on electric fires steaming hot and turning brown.
I don't live in Somerset, but I can assure you that's nothing like reality in the UK - it's certainly NOT common for live and neutral to be wrongly connected, or for the earth screw to be lose - and I've been in thousands of homes installing electrical items and never found one like that.
The sockets are perfectly fine for 13A, and a double socket often feeds two 13A loads at the same time - that's why we have ring mains in the UK.
I have seen occasional plugs on 3KW heaters burnt and brown, but that's normally because the plug was fitted poorly (not correctly tightening the screws, making a 'high' resistance connection that gets hot) - and the heat from the plug pins can also damage the socket.
My electricity is always about 123VAC and the transformers on my street were replaced a few months ago since they were 30 years old. Homes are heated with natural gas not electricity.
Old incandescent Christmas tree and Christmas home lights used a lot of electricity but now the current is reduced by LED lights.
But in summer we are nearing a brownout condition when many air conditioners are used.
giving away coupons for LED light bulbs
So the utility is doing "Peak saver" rewiring of the air conditioners.. and replacing the thermostats with cell phone controlled ones. Now they can turn off air conditioners to save power. They say only for a couple of hours and we will not notice. Then they can delay or eliminate the need to build another very expensive generating station (probably nuclear).
I also think that most electricians are honest and work properly. The DIY crowd do the most sloppy and wrong home wiring.
I just used Ron S. sim so we would be on the same page. I don't think any of the values make any significant difference to the circuit. I initially thought they were 100 ma diodes, but from looking at them E thought the 50 ma Cree was a better fit. The simulation at 240 volts put the current at 46 ma. so that seemed a good fit.Nice sim.
Presumably R2 & R6 represent the ESR of the capacitor, but why a value of 10 mili Ohms for the 1.5uF cap and 1 Ohm for the 3uF cap?
The individual LED diodes are characterised at 20 mA or 30 mA depending on the actual type used, which is not known, yet you say that 50 mA would be dissapointing. Why is that (genuine question)?
Out of interest, could you do a run on my second circuit to see what that would do? Why my circuits were not tried I can't understand- probably because of all the inuendo and lack of understanding.
I just used Ron S. sim so we would be on the same page. I don't think any of the values make any significant difference to the circuit. I initially thought they were 100 ma diodes, but from looking at them E thought the 50 ma Cree was a better fit. The simulation at 240 volts put the current at 46 ma. so that seemed a good fit.
I have to go out for a bit, but will run your circuit when I get back.
Luminaire designers considerNow I have light. So bright its ugliness is unviewable.
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I took a couple of liberties with your voltage doubler.Thanks Ron
spec
Yes, common was the wrong word, not unknown would have been better. There is no need to use scare caps and bold, I can read just fine. By the way, I was talking about the mains cable from the user device being reversed, not the house wiring- I have never come across that.
I do not agree that a twin socket would be OK with both pasing 13A- maybe when properly installed with matching high end plugs but that is seldom the case. Also it is common for the screws in the plug and socket terminals not to be adequately tight and also for the cable entry to be badly formed. There is a design flaw with the terminals on all sockets because of the use of a single small screw, made of soft brass as the only clamp for the cable.
A ring main is just a convienience. This is made worse, if I remember corectly, because with a ring you need to twist the two 20A solid cores together and then stuff those in the connector. The twisting weakens the core and the little screw also damages the copper, often, and I mean often, the wires are not twisted and one or the other core is not properly secured. It's often said that a ring capacity is twice the value of a single cable, but this is not true for most installations because of the different cable lenths and other risistances in the separate circuits. this means that one ring will pass more current than the other depending on the position of the socket in the ring. By the way, if you really want to see some disaters take a look at emmersion heater wiring.
A star arrangement is the propper approach. A normal domestic ring is done with 2.5 mm2 20 A cable and a 32A fuse. That means that only two sockets in on the whole ring can be used at full power (26A). (by the way, I do know about diversity)
I'm not sure what area you work in, perhaps industrial. I should have clarified that I was talking about domestic and then fairly old. But In 1972, we moved into a brand new house and got an electrical certificate. None of the earth terminals were tight: the earth wires were just dangling in the receptacles. I measured and there was no connection to the earth terminal on the wall sockets.
You do agree that mains plugs and sockets with high currents get hot and brown. The main line manufacturer's sockets and plugs are ok but not the second line stuff.
An older lady lives next door and I seem to have been appointed Mr fixit it. Around nine months ago she knocked on our door in a panic and said that her mains kept going off- I won’t bore you with what I found! Also, last year I bought an 1878 house- I won't tell you what I found with the electrics either in case it upsets you
It's even worse than that, SPEC has sliding doors with hinges on them.your house was obviously a HUGE exception, and used a cowboy electrician - or not an electrician at all?.
It's even worse than that, SPEC has sliding doors with hinges on them.
That wasn't what you said, .
Nigel you are putting slants on everything I say. I seem to spend the majority of my time fighting meaningless battles on ETO. I am tired now.
I thought you'll be amused.I thought you were on my side... turncoat
I thought you would be amused tooI thought you'll be amused.
I'm on your side. I think that UK electrical system is marvelous too, so are brit electricians don't be so up tight and don't put words in my mouth.It's meaningless when you're (presumably deliberately) making misleading statements about the UK electrical system, which is probably the best in the world.
Thanks for the run ron (da do ron ron). The only design aim was for the circuit to work off 120V. The power into the LED string can be increased by increasing the value of the res capacitors to go as bright as you like.I took a couple of liberties with your voltage doubler.
I hooked up the other side of the bridge and modified the resistor to get the current up to the same as the 240 volt model.
Works a okay. But alas, still only 7 watts average.
don't be so up tight and don't put words in my mouth.
Yes sir- so its wire cutters at dawn is it. Anyway, my incorrect statements are more incorrect than yours.In which case think before you post such deliberately incorrect statements!.
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