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Alternatives to "incandescent" test lamps?
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<blockquote data-quote="handsome" data-source="post: 1148018" data-attributes="member: 772"><p>Incandescent light bulb is a resistive piece of wire whose resistance increases with heat. All conductive materials behave this way but lightbulbs filaments are designed to heat up - to get white hot and thus emit light, in use. Wirewound (and other types of) resistors’ resistance will increase slightly with heat but they are not designed to ’get white hot’ hence light bulbs suitability as soft start devices. So building a soft start device using nichrome wire requires calculating volt and current plus knowing the wires characteristics. Light bulb filaments (and valve heaters) will reach a given temperature by design (230V for bulbs, 6.3V for heaters). Light bulbs also glow brightly indicating too much current, nichrome wire won’t. so either stash them lightbulbs or use a known value of resistor plus a voltmeter connected across it to tell you how much current is being drawn…IOW light bulbs are simplest and easiest.</p></blockquote><p></p>
[QUOTE="handsome, post: 1148018, member: 772"] Incandescent light bulb is a resistive piece of wire whose resistance increases with heat. All conductive materials behave this way but lightbulbs filaments are designed to heat up - to get white hot and thus emit light, in use. Wirewound (and other types of) resistors’ resistance will increase slightly with heat but they are not designed to ’get white hot’ hence light bulbs suitability as soft start devices. So building a soft start device using nichrome wire requires calculating volt and current plus knowing the wires characteristics. Light bulb filaments (and valve heaters) will reach a given temperature by design (230V for bulbs, 6.3V for heaters). Light bulbs also glow brightly indicating too much current, nichrome wire won’t. so either stash them lightbulbs or use a known value of resistor plus a voltmeter connected across it to tell you how much current is being drawn…IOW light bulbs are simplest and easiest. [/QUOTE]
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General Discussion
Alternatives to "incandescent" test lamps?
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