The vintage light in question is from the 1950s and hardwired to the household lighting circuit at 240v.
My problem is finding the right wattage/voltage/ampage combination for two very different bulb sizes in the same circuit...please bear with me as I describe the light fitting and my experiments so far...
The light is wired as a series circuit. The first bulb socket in the circuit is a tiny E10 (10mm screw in) intended to create a wash up the front of the light. The second socket in the circuit is a standard boyonet (B22) behind a metal plate, designed so light reflects back onto the wall. The light has been rewired by a qualified restorer, in the original wiring configuration - no changes. The light fitting is hardwired to a 240v household lighting supply. I've attached an image of the light.
Here's the work I've done so far: I tried various bulbs to see if I could find a combination that would work. For example, I put a 240v 3w E10 bulb in the first socket in the series, it lights up fine (as long as a 240v bayonet bulb is in the second socket to complete the circuit), but the bayonet bulb doesn't light up. So I tried 25w, 40w, 60w and 100w bayonet bulbs but none work in the series circuit in combo with the 240v 3w E10.
Then I put a 6.5v 300mA bulb in the E10 fixture, both the E10 and the B22 bulb light up as long as the bayonet bulb is over 40w. I am happy to use a 6.5v 300mA lamp in the series circuit but surely this is going to blow out constantly due to the many times higher voltage power supply?
At this point I guessed that the problem was about combinations of wattage/voltate/ampage/resistance. I read up on Ohms Law and calculated out equations for power (wattage) output using the available variables for current, energy supply, resistance and voltage (using Kirchhoff's Law). I understand now that the problem is the voltage drop on the small lamp - high resistance in a low watt lamp = a big voltage drop and insufficient voltage to light the second, larger and higher watt lamp in the series.
So...
What combination voltage, wattage and ampage of bulbs will work together in this circuit, with each bulb working close to it's wattage capacity?
Would 6.5v 300mA E10s burn out all the time due to 240v supply?
If I use two 120v lamps on this 240v circuit does this solve my problem?
Of course, in an ideal world I could use any combination of lamps for this light, but I am restricted to the voltage, wattage, ampage and resistance of available E10/MES 10mm Screw-in bulbs + B22/Bayonet Cap bulbs.
Any answers greatly appreciated. If you hadn't guessed, I'm not electrical or engineering qualified or skilled in any way but I am very curious about how wattage, voltage, ampage and resistance are interacting in this circuit and I've learned a lot. It's interesting, but I also really want my light to work!
Thanks!
My problem is finding the right wattage/voltage/ampage combination for two very different bulb sizes in the same circuit...please bear with me as I describe the light fitting and my experiments so far...
The light is wired as a series circuit. The first bulb socket in the circuit is a tiny E10 (10mm screw in) intended to create a wash up the front of the light. The second socket in the circuit is a standard boyonet (B22) behind a metal plate, designed so light reflects back onto the wall. The light has been rewired by a qualified restorer, in the original wiring configuration - no changes. The light fitting is hardwired to a 240v household lighting supply. I've attached an image of the light.
Here's the work I've done so far: I tried various bulbs to see if I could find a combination that would work. For example, I put a 240v 3w E10 bulb in the first socket in the series, it lights up fine (as long as a 240v bayonet bulb is in the second socket to complete the circuit), but the bayonet bulb doesn't light up. So I tried 25w, 40w, 60w and 100w bayonet bulbs but none work in the series circuit in combo with the 240v 3w E10.
Then I put a 6.5v 300mA bulb in the E10 fixture, both the E10 and the B22 bulb light up as long as the bayonet bulb is over 40w. I am happy to use a 6.5v 300mA lamp in the series circuit but surely this is going to blow out constantly due to the many times higher voltage power supply?
At this point I guessed that the problem was about combinations of wattage/voltate/ampage/resistance. I read up on Ohms Law and calculated out equations for power (wattage) output using the available variables for current, energy supply, resistance and voltage (using Kirchhoff's Law). I understand now that the problem is the voltage drop on the small lamp - high resistance in a low watt lamp = a big voltage drop and insufficient voltage to light the second, larger and higher watt lamp in the series.
So...
What combination voltage, wattage and ampage of bulbs will work together in this circuit, with each bulb working close to it's wattage capacity?
Would 6.5v 300mA E10s burn out all the time due to 240v supply?
If I use two 120v lamps on this 240v circuit does this solve my problem?
Of course, in an ideal world I could use any combination of lamps for this light, but I am restricted to the voltage, wattage, ampage and resistance of available E10/MES 10mm Screw-in bulbs + B22/Bayonet Cap bulbs.
Any answers greatly appreciated. If you hadn't guessed, I'm not electrical or engineering qualified or skilled in any way but I am very curious about how wattage, voltage, ampage and resistance are interacting in this circuit and I've learned a lot. It's interesting, but I also really want my light to work!
Thanks!
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