If there are only 2 cores (your post isn't too clear) this may be scott tranformer which can used to convert 3 phase to single phase while loading all three phases equaly, google it or try wiki.
The incandescent lamp will draw up to 10 times its normal running current at switch on, measure its cold resistance and compare that to its calculated running value to get a more accurate number. The construction of the lamp will affect the time it needs to warm up and gain resistance.
We do use single phase 415/440v (2 of 3 phases) in the UK within machine control cabinets to power low voltage kit via transformers, usualy for lower power stuff like panel lamps and relays.
This is done to accomodate delta connected power inputs which reduce the power cable count to 3 + ground.
Better still use an instrumentation amp with its gain set around 1000, you only need one resistor to set its gain and maybe an r/c lowpass filter to clean up the signal a little.
With luck you can power it from the excitation voltage.
Lots are available from the usual semiconductor folks...
In my old austin healy 100 (1954 when flashing turn indicators were a novelty on the UK roads) there was a dual relay box (one relay for each side) which took both the brake lamp and signal wires in and sorted out which feed to send to each lamp, it was a standard Lucas part. If I can find the...
No patents there it is just a fat magnet loose (axialy)inside a coil this forms an AC generator, the torch things have a rectifier to turn the AC to DC which charges a supercap to store some electricity. The avalible power is quite low.
Try reading the oven makers handbook, usualy dishware is marked as being suitable for use in such devices if its not marked so it may as you found explode or at least the glaze will tend to craze.
I doubt that the switch is becoming magnetized, its more likly that inrush currents are welding the switch closed.
Have a look at some reed switch makers websites for what you should avoid when using reed switches, one no no is capacitance across the switch or the switched load.
My solution to this problem, (we wanted 2v of 400hz and its harmonics on top of a 28v 2A DC supply) was inject the required signal (via a capacitor) into a resistor tied to the summing junction of the psu control amp, at the end of the voltage pot on a farnell L30B bench unit. It seemed OK up to...
The mirror works by establishing a Vbe on the input transistor that will provide a collector current equal to the input current, that is to say that the Vbe developed is appropriate for that particular transistor at whatever input current is supplied, it follows that if another transistor (At...
A very high performance linear supply is normaly required.
You may have mains bourne interference causing your error voltage. Make sure that the signal and supply pairs are well twisted and if possible use an overall screen on the load cell cable.
To overcome AC mains interference an AC...
The bipolar 555 has a nasty switching characteristic it puts both the sink and source on for a few nano seconds when the output changes state this draws a horrid hefty and fast edged pulse(>500mA)from the supply which will invariably drop in response to the pulse, it is essential that very good...
