Recent content by darkwood

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    What happens to the current when an electric motor slows to a halt?

    In response to the initial question we would need more detail, there are many reasons for a motor to slow to a halt but I assume we are talking about motor failing to carry on with the work it is trying to do possibly for mechanical failure while still been fully energised to do the work...
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    Circuit Diagrams versus Logic Diagrams

    I integrate both systems into wiring/logic details... To explain, I show a conventional wiring diagram with all the value's etc or at least a key reference if it would clutter the diagram, where they terminate to a PLC it is just ID'd as it's part code. All logic maps, timing values, boolean...
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    Wanted: B Level Explanation of Conduction and Resistance

    I never mentioned the positive/negative charge status in my analogy so fail to see how I get it backwards or that my analogy got is somehow backwards, yes I agree with you in that the OP is after a more complex analogy that covers and explains the wider picture but here lies the problems with...
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    Wanted: B Level Explanation of Conduction and Resistance

    You can imagine electron flow like a hosepipe full of a line of ball bearings, when you push a new ball bearing into one end of the hose you get one that falls out almost instantly at the other end, there has been little movement of any given electron (ball bearing) but the reaction (charge)...
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    UV light + electric current = boom?

    So I guess we go back to the lying little lad scenario which with 30yrs experience in this trade was my first thought and most likely scenario; with a gullible father to boot o:)
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    UV light + electric current = boom?

    I would suggest that we are all getting a little exited with the theories here when we haven't ruled out the most probable answer, even though the son says he was doing nothing more than shining the UV led into the switch the odds are because it went bang and the son realized he was in big...
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    Beauty of old electrical and measuring things, etc.

    @dlgoff Yes its in what used to be an old textile mill in West Yorkshire UK which it would have been operating a lift between 2 floors only. Edit ... Yes! I forgot to say ignore the spare lamp, there are actually 2 mercury bulbs one behind the other, the beads were used because of the flexing...
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    Beauty of old electrical and measuring things, etc.

    An old abandoned lift control room.
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    Beauty of old electrical and measuring things, etc.

    Here is a very old relay from a Grinder built around about WWII, using the once popular technique of mercury switching, note the wires are insulated with insulating porcelain beads.
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    What do Red and Green Indicator Lamps Mean for Machinery Operation?

    Here in the UK we follow the EU Low Voltage Directive and under our own Machinery code BS60204 Red indicator - Emergency (Hazardous Condition) Green indicator - Normal condition Like others have said there are many exceptions and the regulations do state 'unless otherwise agreed' so there is...
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    News Is Anyone Truly in Control Amidst the Ukrainian Crisis?

    Here's my input... Eastern Ukraine are manufacturers of parts for weapons that cannot be got anywhere else in the world and they are heavy suppliers to Russia and China so the thought to Putin that Ukraine could fall into the hands of the EU is very worrying to him as it could effectively...
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    Is It Safe to Use MCBs as Regular On/Off Switches?

    MCB is common terminology here in England for Miniature Circuit Breaker and modern MCB's that comply to BS60898 can be used as functional switching for say lights but in the capacity of design of the installation this would be regarded as poor design and practice. Older MCB's you will often...
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    Sensor Setup: Touch to Light, Buy & Cost, Cheap Price

    Read the link I posted it explains ... you don't apply force as such to operate it, it uses the presence of your finger which is electrically detected not detected by physically pressure.
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    Sensor Setup: Touch to Light, Buy & Cost, Cheap Price

    Your best option here would be a capacitive touch sensor which can be miniature relatively cheap and simple to use or the more robust options available out there can get quite expensive ... The market of touch sensitive equipment, buttons sensors is quite large and come in many forms and...
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    Is it OK to use 220V Solenoid Valve in a 230 V Environment

    Depending on your location the 230v Environment maybe misguided figure. Here in the UK we had a 240v set-up for many years but to conform with EU legislation this was changed to 230v. The power we use is still a majority 240v as the measured average voltage rarely meets the 230v figure in favour...
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