news@bbn.COM (News system owner ID) (05/31/89)
For several years, I have been using a mechanical timer from Sears to control a table lamp. This has allowed me to have lighting when I come home without operating the light all day. From: gonzalez@bbn.com (Jim Gonzalez) Path: bbn.com!gonzalez About a year ago, a lamp I had attached to the timer failed. It would not supply power to the bulb, even when plugged directly into a wall outlet. I gave up on it, figuring it was a cheap lamp. The lamp I bought to take its place has just failed. The switch on the socket now requires jiggling to get it to throw, and there is crackling in the housing once it is on. The timer is rated for 15A load. The lamps were both simple incandescents. Lamp failure in both cases was followed a string of short-lived bulbs (GE Watt Miser 70 and 90-watt bulbs in 100-watt fixtures). Switches for each were socket-mounted. Is it possible that the mechanical timer is causing damage to the lamp switches? Could a bouncy timer switch generate impulses that would damage the contacts in the lamp switch? Has anyone else had this problem? -Jim. ---------------------------------------------------------------------- Jim Gonzalez AT&T: 617-873-2937 BBN Systems and Technologies Corp. ARPA: gonzalez@bbn.com Cambridge, Massachusetts UUCP: ...seismo!bbn!gonzalez ----------------------------------------------------------------------
irwin@m.cs.uiuc.edu (05/31/89)
/* Written 4:22 pm May 30, 1989 by news@bbn.COM in m.cs.uiuc.edu:sci.electronics */ /* ---------- "Mechanical Light Timer Problem" ---------- */ >For several years, I have been using a mechanical timer from Sears >to control a table lamp. This has allowed me to have lighting when >I come home without operating the light all day. >About a year ago, a lamp I had attached to the timer failed. It >would not supply power to the bulb, even when plugged directly into >a wall outlet. I gave up on it, figuring it was a cheap lamp. >The lamp I bought to take its place has just failed. The switch on >the socket now requires jiggling to get it to throw, and there is >crackling in the housing once it is on. The timer is rated for 15A >load. The lamps were both simple incandescents. Lamp failure in >both cases was followed a string of short-lived bulbs (GE Watt Miser >70 and 90-watt bulbs in 100-watt fixtures). Switches for each were >socket-mounted. >Is it possible that the mechanical timer is causing damage to the >lamp switches? Could a bouncy timer switch generate impulses that >would damage the contacts in the lamp switch? Has anyone else had >this problem? > -Jim. ---------------------------------------------------------------------- >Jim Gonzalez AT&T: 617-873-2937 >BBN Systems and Technologies Corp. ARPA: gonzalez@bbn.com >Cambridge, Massachusetts UUCP: ...seismo!bbn!gonzalez ---------------------------------------------------------------------- /* End of text from m.cs.uiuc.edu:sci.electronics */ I doubt if the timer has anything to do with the failure of the switches. Lamp switches seem to be underdesigned and are notorious for having problems. There are two common types of lamp switches, one rotates and the other is a push type, push in on one side to turn it on and push in on the other side to turn it off. I find the push type to be the more reliable of the two. You can purchase these types of sockets/switches at the hardware. You could replace the socket with one of these if you feel that you DO want a switch on the lamp, of course you have to reach up into the shade to reach the switch. A no switch socket could be used and a good quality toggle switch could be mounted in the base of the lamp also. Since your timer turns the lamp on and off, why don't you remove the switch and wire direct from the lamp power plug to the bulb socket, if the switch is external to the socket?? --al--
torkil@psivax.UUCP (Torkil Hammer) (06/01/89)
In article <40651@bbn.COM> gonzalez@vax.bbn.com (Jim Gonzalez) writes:
#
#About a year ago, a lamp I had attached to the timer failed. It
#would not supply power to the bulb, even when plugged directly into
#a wall outlet. I gave up on it, figuring it was a cheap lamp.
#
#The lamp I bought to take its place has just failed. The switch on
#the socket now requires jiggling to get it to throw, and there is
#crackling in the housing once it is on. The timer is rated for 15A
#load. The lamps were both simple incandescents. Lamp failure in
#both cases was followed a string of short-lived bulbs (GE Watt Miser
#70 and 90-watt bulbs in 100-watt fixtures). Switches for each were
#socket-mounted.
The timer didn't do it.
The damage you describe is typical for overheating. Overheating occurs
1. If you use higher bulb wattage than the fixture is rated for
(You didn't do that)
2. If the fixture is placed so it does not get enough cooling. This is
more likely to be your problem, as it is worse with high wattage bulbs
(70 and 90). Even though the lamp is rated for 100 watts, those watts
have to be cooled away by air convection - just like heat from a TV.
Use a smaller bulb or move the lamp away from the wall and make sure
that it does not stand right under a shelf or ceiling that can obstruct
the air. Also, if you plan on using 90 watt bulbs, don't buy a cheap
lamp.
Good luck
torkilmack@cive.ri.cmu.edu (Clark McDonald) (06/07/89)
>From: gonzalez@bbn.com (Jim Gonzalez) >Path: bbn.com!gonzale >Is it possible that the mechanical timer is causing damage to the >lamp switches? Could a bouncy timer switch generate impulses that >would damage the contacts in the lamp switch? Has anyone else had >this problem? > > -Jim. > >---------------------------------------------------------------------- >Jim Gonzalez AT&T: 617-873-2937 >BBN Systems and Technologies Corp. ARPA: gonzalez@bbn.com >Cambridge, Massachusetts UUCP: ...seismo!bbn!gonzalez >---------------------------------------------------------------------- I think that the problem lies in the fact that the switch located on the lamps was left in one position too long. Those switches are usually designed to be self-cleaning when operated. If the contacts are left in the closed (or open) position for extended periods, the wiping action produced when turning the switch is defeated. Corrosion, cigarette smoke (a biggie in home audio switches), forced-air heating/cooling systems and the like do big damage to plated contacts over time. Every once in a while, you should OPERATE the switch of the lamp to clean it. If not, you will end up with the troubles you describe, which get worse and worse steadily with time. Once an AC power switch starts this behavior, I have never seen one that could be brought "back to life" with cleaning agents, etc. The cure is to replace the switch. Then, USE IT every once in a while. An alternative would be to simply throw the switch several times with the power OFF to initiate the wiping action described above. Disclaimer: Disclaimer? I don't even know 'er. But BE CAREFUL if you are replacing the switch yo' sef. --