The transformers used for aircraft ground lights have a set current all wired in series and these then have a volts output to work the light so every lamp has the same output.
Hm. What happens if one of the lamps blow?
The transformers used for aircraft ground lights have a set current all wired in series and these then have a volts output to work the light so every lamp has the same output.
Much less than would happen if the bulbs/lamps themselves (rather than their transformers) were wired in series - that is surely the point?Hm. What happens if one of the lamps blow?The transformers used for aircraft ground lights have a set current all wired in series and these then have a volts output to work the light so every lamp has the same output.
Much less than would happen if the bulbs/lamps themselves (rather than their transformers) were wired in series - that is surely the point?Hm. What happens if one of the lamps blow?The transformers used for aircraft ground lights have a set current all wired in series and these then have a volts output to work the light so every lamp has the same output.
Kind Regards, John
Indeed - so I can but presume that each transformer has a load connected across its secondary in addition to the lamp/bulb, so as to avoid that problem (in the event of an o/c lamp/bulb).But you have already said: "As you know, that's why leaving the secondary of CT open-circuit can be dangerous/damaging, since the voltage tries to rise to 'infinitely high' (the CT equivalent of putting a short-circuit across the secondary of a 'voltage transformer', when the current attempts to rise to 'infinitely high'))".
You loose one landing lamp. That is why transformers in series not bulbs. I will admit on the Falklands where this system was used, I was not directly involved with runway lighting, but saw the transformers and asked what they were for and the system was explained to me. Runways are very long and for the planes navigation equipment to work correctly and to assist the pilot they want all lights giving out the same amount of light. It seems this system does that.The transformers used for aircraft ground lights have a set current all wired in series and these then have a volts output to work the light so every lamp has the same output.
Hm. What happens if one of the lamps blow?
Yes, I've made that point. However, as I said, since they are being used as current transformers, the secondary voltage would be expected to get very, maybe catastrophically, high if a lamp/bulb blew o/c, unless there was also some other load across the secondary. Do you recall if there was such an additional load (or 'burden')?You loose one landing lamp. That is why transformers in series not bulbs.Hm. What happens if one of the lamps blow?
The transformers are designed to have a constant primary impedance irrespective of the loading on the secondary. ( from memory )
In a perfect transformer ( purely inductive with zero DC resistance in the windings ) that is true. By intentionally designing a less than "perfect" transformer any variation of the secondary load has less effect on the primary impedance.The primary impedance is the square of the turns ratio times the secondary load impedance.
Like winston, that's the bit I find difficult to understand. If (in some 'specially-designed' transformer) applying the load to a secondary didn't alter the primary impedance, I am struggling to see how it could supply power to that load.The transformers are designed to have a constant primary impedance irrespective of the loading on the secondary. ( from memory )
As I understand it ....I do remember doing transformers in University and working out how many turns were required. ... As a young lad I thought it was simply a ratio ... So there is a set number of turns which can be calculated.
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