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UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
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#1
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How do light switch security timers work?
A friend asked me to have a look at a Superswitch 2304 timer which
stopped working when the bulb which it was switching blew, and replacing the bulb didn't fix it. The answer, of course, was that when the bulb blew, so did an internal 3A fuse in the timer. But, having had a look at the thing, I don't understand how it works. It replaces a conventional wall switch and only has 2 connections - live and switched live. Yet the thing itself needs power to operate the display/logic/relay, etc. - and it doesn't have a neutral connection. My first thought was that maybe it gets a connection from an earthed backbox - but the holding screws go through insulated sleeves, and don't connect to the circuit board. My next thought was that it could get a neutral connection through the bulb (it apparently only works with tungsten bulbs). But surely, that would only work when the light was off. Once it had switched the light on, the live and switched live would be at the same voltage and wouldn't be able to power it to do any further timing/displaying/switching. Clearly, I must be missing something! Anybody know what? -- Cheers, Roger ____________ Please reply to Newsgroup. Whilst email address is valid, it is seldom checked. |
#2
Posted to uk.d-i-y
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How do light switch security timers work?
On Wed, 26 Apr 2017 23:31:44 +0100, Roger Mills
wrote: A friend asked me to have a look at a Superswitch 2304 timer which stopped working when the bulb which it was switching blew, and replacing the bulb didn't fix it. The answer, of course, was that when the bulb blew, so did an internal 3A fuse in the timer. But, having had a look at the thing, I don't understand how it works. It replaces a conventional wall switch and only has 2 connections - live and switched live. Yet the thing itself needs power to operate the display/logic/relay, etc. - and it doesn't have a neutral connection. My first thought was that maybe it gets a connection from an earthed backbox - but the holding screws go through insulated sleeves, and don't connect to the circuit board. My next thought was that it could get a neutral connection through the bulb (it apparently only works with tungsten bulbs). But surely, that would only work when the light was off. Once it had switched the light on, the live and switched live would be at the same voltage and wouldn't be able to power it to do any further timing/displaying/switching. Clearly, I must be missing something! Anybody know what? A battery or supercapacitor. -- Graham. %Profound_observation% |
#4
Posted to uk.d-i-y
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How do light switch security timers work?
Roger Mills submitted this idea :
Clearly, I must be missing something! Anybody know what? When the switch is off, there is potential/ voltage across the two terminals. That potential charges either a tiny battery, or a specialised capacitor so it has a power source when the light is on and there is no potential across the switch. Most likely problem if the fuse has been blown by the lamp, is that the Triac has also been blown or possibly the relay, if it uses a relay for switching. |
#5
Posted to uk.d-i-y
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How do light switch security timers work?
Harry Bloomfield wrote:
Roger Mills submitted this idea : Clearly, I must be missing something! Anybody know what? When the switch is off, there is potential/ voltage across the two terminals. That potential charges either a tiny battery, or a specialised capacitor so it has a power source when the light is on and there is no potential across the switch. Most likely problem if the fuse has been blown by the lamp, is that the Triac has also been blown or possibly the relay, if it uses a relay for switching. Even when the lamp appears to be on the capacitor can be charged during the first few degrees of each cycle without any noticeable effect on the lamp brightness. |
#6
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How do light switch security timers work?
"Roger Mills" wrote in message ... A friend asked me to have a look at a Superswitch 2304 timer which stopped working when the bulb which it was switching blew, and replacing the bulb didn't fix it. The answer, of course, was that when the bulb blew, so did an internal 3A fuse in the timer. But, having had a look at the thing, I don't understand how it works. It replaces a conventional wall switch and only has 2 connections - live and switched live. Yet the thing itself needs power to operate the display/logic/relay, etc. - and it doesn't have a neutral connection. My first thought was that maybe it gets a connection from an earthed backbox - but the holding screws go through insulated sleeves, and don't connect to the circuit board. My next thought was that it could get a neutral connection through the bulb (it apparently only works with tungsten bulbs). But surely, that would only work when the light was off. Once it had switched the light on, the live and switched live would be at the same voltage and wouldn't be able to power it to do any further timing/displaying/switching. Clearly, I must be missing something! Anybody know what? According to the manual, it has an internal rechargeable battery that needs 2 hours with switch turned ON to charge from cold, and then gives 24 hour backup. When ON there must be a small voltage drop across the unit high enough to supply the charging current, and the display is run from the battery at all times. The 400W max bulb would take 1.7A, so if the voltage drop across the unit is say 1.5V to be able to charge an NmH cell, less than 3W is dissipated in the unit. The small voltage is what might be expected across a triac when conducting. -- Dave W |
#7
Posted to uk.d-i-y
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How do light switch security timers work?
On 26/04/2017 23:31, Roger Mills wrote:
A friend asked me to have a look at a Superswitch 2304 timer which stopped working when the bulb which it was switching blew, and replacing the bulb didn't fix it. The answer, of course, was that when the bulb blew, so did an internal 3A fuse in the timer. But, having had a look at the thing, I don't understand how it works. It replaces a conventional wall switch and only has 2 connections - live and switched live. Yet the thing itself needs power to operate the display/logic/relay, etc. - and it doesn't have a neutral connection. My first thought was that maybe it gets a connection from an earthed backbox - but the holding screws go through insulated sleeves, and don't connect to the circuit board. My next thought was that it could get a neutral connection through the bulb (it apparently only works with tungsten bulbs). But surely, that would only work when the light was off. Once it had switched the light on, the live and switched live would be at the same voltage and wouldn't be able to power it to do any further timing/displaying/switching. Clearly, I must be missing something! Anybody know what? Yup you are right, it draws its power through the lamp (hence the filament lamp restriction). Its a very low level current draw and hence not enough to light the "off" lamp. As to how its powered while the lamp is on, there are several ways it is done - depending a bit on the switch design. One option is to just keep a backup power source charged when the lamp is off. However that is sub optimal since you don't know how long the lamp will be on for, and whether there is sufficient "off" time to keep it charged. Better options will still allow it to draw power when the lamp is on, usually at the expense of dropping a small voltage in the switch. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#8
Posted to uk.d-i-y
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How do light switch security timers work?
On 27/04/2017 12:41, John Rumm wrote:
On 26/04/2017 23:31, Roger Mills wrote: A friend asked me to have a look at a Superswitch 2304 timer which stopped working when the bulb which it was switching blew, and replacing the bulb didn't fix it. The answer, of course, was that when the bulb blew, so did an internal 3A fuse in the timer. But, having had a look at the thing, I don't understand how it works. It replaces a conventional wall switch and only has 2 connections - live and switched live. Yet the thing itself needs power to operate the display/logic/relay, etc. - and it doesn't have a neutral connection. My first thought was that maybe it gets a connection from an earthed backbox - but the holding screws go through insulated sleeves, and don't connect to the circuit board. My next thought was that it could get a neutral connection through the bulb (it apparently only works with tungsten bulbs). But surely, that would only work when the light was off. Once it had switched the light on, the live and switched live would be at the same voltage and wouldn't be able to power it to do any further timing/displaying/switching. Clearly, I must be missing something! Anybody know what? Yup you are right, it draws its power through the lamp (hence the filament lamp restriction). Its a very low level current draw and hence not enough to light the "off" lamp. As to how its powered while the lamp is on, there are several ways it is done - depending a bit on the switch design. One option is to just keep a backup power source charged when the lamp is off. However that is sub optimal since you don't know how long the lamp will be on for, and whether there is sufficient "off" time to keep it charged. Better options will still allow it to draw power when the lamp is on, usually at the expense of dropping a small voltage in the switch. Thanks for all the replies. I can't see anything which looks like a battery in it - but it does have a 6.3v 1000 uF capacitor (the blue one towards to bottom RH corner of https://app.box.com/s/no8ccg03hf7yr2f8odqlfw9r03fael5z) which may well store some energy. I don't know whether it would still work if I replaced the fuse - I didn't have a 3A BS646 fuse to hand - and my friend asked me to replace it with a simple on/off switch, so I haven't had an opportunity to test it. -- Cheers, Roger ____________ Please reply to Newsgroup. Whilst email address is valid, it is seldom checked. |
#9
Posted to uk.d-i-y
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How do light switch security timers work?
replying to Roger Mills, Eamonn wrote:
Iam not sure either but I have a Superswitch 2304 for about 15 years and now the LCD is unreadable so I cannot set the time. Do you remember how to reorder this switch as I have been very happy with it up to now, also my swith has 3 connection terminals at the back Regards Eamonn -- for full context, visit https://www.homeownershub.com/uk-diy...k-1205175-.htm |
#10
Posted to uk.d-i-y
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How do light switch security timers work?
How old is this one I wonder.
Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Eamonn" m wrote in message oupdirect.com... replying to Roger Mills, Eamonn wrote: Iam not sure either but I have a Superswitch 2304 for about 15 years and now the LCD is unreadable so I cannot set the time. Do you remember how to reorder this switch as I have been very happy with it up to now, also my swith has 3 connection terminals at the back Regards Eamonn -- for full context, visit https://www.homeownershub.com/uk-diy...k-1205175-.htm |
#11
Posted to uk.d-i-y
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How do light switch security timers work?
Brian Gaff (Sofa 2) wrote How old is this one I wonder. Not even 3 years, a mere toddler. "Eamonn" m wrote in message oupdirect.com... replying to Roger Mills, Eamonn wrote: Iam not sure either but I have a Superswitch 2304 for about 15 years and now the LCD is unreadable so I cannot set the time. Do you remember how to reorder this switch as I have been very happy with it up to now, also my swith has 3 connection terminals at the back Regards Eamonn -- for full context, visit https://www.homeownershub.com/uk-diy...k-1205175-.htm |
#12
Posted to uk.d-i-y
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Lonely Auto-contradicting Psychotic Senile Ozzie Troll Alert! LOL
On Tue, 11 Feb 2020 08:24:15 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: How old is this one I wonder. Not even 3 years, a mere toddler. If someone wanted to hear an asshole, they'd have farted, senile asshole! -- Website (from 2007) dedicated to the 85-year-old trolling senile cretin from Oz: https://www.pcreview.co.uk/threads/r...d-faq.2973853/ |
#13
Posted to uk.d-i-y
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How do light switch security timers work?
That should have lasted longer than it did. I think I'd send it back and act
a built dumb saying how you feel they really should know about this problem, and they may take pity and send you a new one. I had a thermometer gadget like this some years ago and the company sent me a new one and the new one lasted 10 years, so the first one obviously had a crap display from the start. Of course now I like talking thermometers etc, and now we have other issues with one no longer saying the decimal point only the degrees. You just cannot get reliable tech these days. grin. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Rod Speed" wrote in message ... Brian Gaff (Sofa 2) wrote How old is this one I wonder. Not even 3 years, a mere toddler. "Eamonn" m wrote in message oupdirect.com... replying to Roger Mills, Eamonn wrote: Iam not sure either but I have a Superswitch 2304 for about 15 years and now the LCD is unreadable so I cannot set the time. Do you remember how to reorder this switch as I have been very happy with it up to now, also my swith has 3 connection terminals at the back Regards Eamonn -- for full context, visit https://www.homeownershub.com/uk-diy...k-1205175-.htm |
#14
Posted to uk.d-i-y
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How do light switch security timers work?
Brian Gaff (Sofa 2) wrote
That should have lasted longer than it did. I think I'd send it back and act a built dumb saying how you feel they really should know about this problem, and they may take pity and send you a new one. Yeah, I sent a not very polite email to the manufacturer of one of these which had failed outside the stated warranty and was a bit surprised to have them send me a new one. Culinare One Touch Automatic Jar Opener And another when that one failed. Which reminds me, the latest has failed too. They don’t seem to be able to make it strong enough. I had a thermometer gadget like this some years ago and the company sent me a new one and the new one lasted 10 years, so the first one obviously had a crap display from the start. Of course now I like talking thermometers etc, and now we have other issues with one no longer saying the decimal point only the degrees. You just cannot get reliable tech these days. grin. Your iphone leaves the previous phones for dead. Havent had any failures with the Hue lights or the alexa or google home mini either and I have a few of them now. "Rod Speed" wrote in message ... Brian Gaff (Sofa 2) wrote How old is this one I wonder. Not even 3 years, a mere toddler. "Eamonn" m wrote in message oupdirect.com... replying to Roger Mills, Eamonn wrote: Iam not sure either but I have a Superswitch 2304 for about 15 years and now the LCD is unreadable so I cannot set the time. Do you remember how to reorder this switch as I have been very happy with it up to now, also my swith has 3 connection terminals at the back Regards Eamonn -- for full context, visit https://www.homeownershub.com/uk-diy...k-1205175-.htm |
#15
Posted to uk.d-i-y
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Lonely Auto-contradicting Psychotic Senile Ozzie Troll Alert! LOL
On Wed, 12 Feb 2020 04:32:25 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: Yeah, I sent a not very polite email to the manufacturer of What a "surprise", you cantankerous, senile auto-contradictor! LMAO -- Sqwertz to Rot Speed: "This is just a hunch, but I'm betting you're kinda an argumentative asshole. MID: |
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