CFL on photo on/off?
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From: David Nebenzahl on 12 Mar 2010 14:41 On 3/12/2010 10:52 AM Meat Plow spake thus: > On Fri, 12 Mar 2010 10:42:15 -0800, David Nebenzahl > <nobody(a)but.us.chickens>wrote: > >> On 3/12/2010 7:02 AM William R. Walsh spake thus: >> >>>> The problem is that these photosensitive devices draw their power >>>> through the lamp, so there's a trickle of current flowing even when >>>> it's supposed to be off. With an incandecent lamp, this doesn't >>>> matter. >>> >>> I'm glad someone brought this up, because there is something I'd like >>> to know. >>> >>> I've got an outdoor porch light on a post that has a 100 watt >>> equivalent CFL bulb in it. The fixture itself is made of cheap >>> plastic, and the light is on fairly often, so I feel better using the >>> CFL as opposed to a 100 watt incandescent. (However, I haven't noticed >>> a maximum wattage rating on the fixture itself.) >>> >>> I'd like to switch this light via photocell. >> >> Keep in mind that CFLs are often not good candidates for this kind >> of application, because the length of time they take to warm up is >> often the same as the length of time they're on, so they don't do a >> very good job of lighting up the area you want illuminated. For an >> intermittent application like this, it's probably just as >> cost-effective overall just to use a good old-fashioned >> incandescent lamp. > > But it would be ok for a dusk to dawn security light? Yup, that would be a good place for a CFL. (Assuming it plays nicely with the controller, that is.) -- You were wrong, and I'm man enough to admit it. - a Usenet "apology"
From: Michael A. Terrell on 12 Mar 2010 22:23 David Nebenzahl wrote: > > On 3/12/2010 10:52 AM Meat Plow spake thus: > > > On Fri, 12 Mar 2010 10:42:15 -0800, David Nebenzahl > > <nobody(a)but.us.chickens>wrote: > > > >> On 3/12/2010 7:02 AM William R. Walsh spake thus: > >> > >>>> The problem is that these photosensitive devices draw their power > >>>> through the lamp, so there's a trickle of current flowing even when > >>>> it's supposed to be off. With an incandecent lamp, this doesn't > >>>> matter. > >>> > >>> I'm glad someone brought this up, because there is something I'd like > >>> to know. > >>> > >>> I've got an outdoor porch light on a post that has a 100 watt > >>> equivalent CFL bulb in it. The fixture itself is made of cheap > >>> plastic, and the light is on fairly often, so I feel better using the > >>> CFL as opposed to a 100 watt incandescent. (However, I haven't noticed > >>> a maximum wattage rating on the fixture itself.) > >>> > >>> I'd like to switch this light via photocell. > >> > >> Keep in mind that CFLs are often not good candidates for this kind > >> of application, because the length of time they take to warm up is > >> often the same as the length of time they're on, so they don't do a > >> very good job of lighting up the area you want illuminated. For an > >> intermittent application like this, it's probably just as > >> cost-effective overall just to use a good old-fashioned > >> incandescent lamp. > > > > But it would be ok for a dusk to dawn security light? > > Yup, that would be a good place for a CFL. (Assuming it plays nicely > with the controller, that is.) They sell dusk to dawn security lights made for CFL. My dad installed one with a 65 Watt CFL he bought at Lowe's or Home Depot for his place. It was several years ago and he doesn't remember, for sure. He also bought a smaller one, to light the sidewalk to his driveway. -- Lead free solder is Belgium's version of 'Hold my beer and watch this!'
From: [SMF] on 13 Mar 2010 00:09 On 3/12/2010 9:02 AM, William R. Walsh wrote: > Hi! > >> The problem is that these photosensitive devices draw their power >> through the lamp, so there's a trickle of current flowing even when >> it's supposed to be off. With an incandecent lamp, this doesn't >> matter. > > I'm glad someone brought this up, because there is something I'd like > to know. > > I've got an outdoor porch light on a post that has a 100 watt > equivalent CFL bulb in it. The fixture itself is made of cheap > plastic, and the light is on fairly often, so I feel better using the > CFL as opposed to a 100 watt incandescent. (However, I haven't noticed > a maximum wattage rating on the fixture itself.) > > I'd like to switch this light via photocell. > > To prevent any possible "abuse" to the CFL, I'd like to have the > photocell device turn a relay on and off. Is it possible to do that, > or would it result in unacceptable behavor (buzzing, etc) from the > relay? > > If it won't work, I could always use a timer of some sort. > > William You shouldn't have any problems running a relay with a photo-cell.
From: GregS on 15 Mar 2010 09:20 In article <3j8eko.9cf.19.5(a)news.alt.net>, Meat Plow wrote: >What is the problem with operating a CFL on a dusk to dawn device that >uses a photo sensor? Does it suffer the same fate as running the CFL >on a dimmer that is full on? That's my guess. My motion sensor >security light has an option to turn the lamps on manually and shut >them off in the morning automatically when it's light enough out. But >it has a relay that makes an aduible click. I would assume a simple >light sensing fixture is switched with a triac and this causes a >pulsedvoltage that harms the CFL ballast. Most photodensors use a relay. No different from a switch. greg
From: GregS on 15 Mar 2010 09:24
In article <hnlbvt$g53$2(a)usenet01.srv.cis.pitt.edu>, zekfrivo(a)zekfrivolous.com (GregS) wrote: >In article <3j8eko.9cf.19.5(a)news.alt.net>, Meat Plow wrote: >>What is the problem with operating a CFL on a dusk to dawn device that >>uses a photo sensor? Does it suffer the same fate as running the CFL >>on a dimmer that is full on? That's my guess. My motion sensor >>security light has an option to turn the lamps on manually and shut >>them off in the morning automatically when it's light enough out. But >>it has a relay that makes an aduible click. I would assume a simple >>light sensing fixture is switched with a triac and this causes a >>pulsedvoltage that harms the CFL ballast. > >Most photodensors use a relay. No different from a switch. > >greg That said, I don't remember if there was a warning, but I can hear a click on mine. I used to keep it on, and would last a year or more. I'll see how long it lasts not with a sensor, along with two led spotlights. greg |