Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
|
#1
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
My wife's reading lamp failed. I replaced the 100W 120V halogen bulb,
which did no good so I pulled out the dimmer circuit. I know nothing about these but after googling for light dimmer I found this: http://www.epanorama.net/documents/l...mmer.html#120v The "typical 120V AC dimmer circuit" uses almost the same components that are on my dimmer: two diodes cap resistor pot diac triac The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? |
#2
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
"Bob Simon" wrote in message ... The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? Not easily. What happens if you bypass the dimmer? |
#3
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On Mon, 19 Mar 2007 17:51:50 GMT, "Homer J Simpson"
wrote: "Bob Simon" wrote in message .. . The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? Not easily. What happens if you bypass the dimmer? You mean send 120V directly to the bulb? I just tested resistance on the leads that go to the socket and found 10.3 ohms. Doesn't this prove the same thing: continuity to the bulb and a non-open filament? |
#4
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On Mon, 19 Mar 2007 16:03:23 -0500, Bob Simon
wrote: On Mon, 19 Mar 2007 17:51:50 GMT, "Homer J Simpson" wrote: "Bob Simon" wrote in message . .. The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? Not easily. What happens if you bypass the dimmer? You mean send 120V directly to the bulb? I just tested resistance on the leads that go to the socket and found 10.3 ohms. Doesn't this prove the same thing: continuity to the bulb and a non-open filament? I tried it anyway and it lit up brightly. At least my wife can use the lamp until I get the dimmer fixed. Thanks. |
#5
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
"Bob Simon" wrote in message ... You mean send 120V directly to the bulb? I just tested resistance on the leads that go to the socket and found 10.3 ohms. Doesn't this prove the same thing: continuity to the bulb and a non-open filament? Probably, but assumptions waste more repair time than anything else. |
#6
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
The diodes test good one way so I wonder if either the BT137F triac or
the DB3 diac are the problem. Can these be tested with a VOM? With that low part count, replace both. Sometimes "shotgun" troubleshooting pays off compared to time spent testing. After confirming that all the other components test good (cap, *switch*, etc.)... |
#7
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On Mon, 19 Mar 2007 11:23:05 -0700, SparkyGuy
wrote: The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? With that low part count, replace both. Sometimes "shotgun" troubleshooting pays off compared to time spent testing. After confirming that all the other components test good (cap, *switch*, etc.)... Thank you. That sounds like a good idea -- especially since I've already removed the diac from the board. |
#8
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
Bob Simon wrote:
My wife's reading lamp failed. I replaced the 100W 120V halogen bulb, which did no good so I pulled out the dimmer circuit. I know nothing about these but after googling for light dimmer I found this: http://www.epanorama.net/documents/l...mmer.html#120v The "typical 120V AC dimmer circuit" uses almost the same components that are on my dimmer: two diodes cap resistor pot diac triac The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? Usually triacs fail shorted, you'll want to rule out the easy stuff first. Switch, variable resistor, etc. If the lamp doesn't light at all my first suspect aside those already mentioned is the diac. |
#9
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On Mon, 19 Mar 2007 12:23:07 -0500, Bob Simon
wrote: My wife's reading lamp failed. I replaced the 100W 120V halogen bulb, which did no good so I pulled out the dimmer circuit. I know nothing about these but after googling for light dimmer I found this: http://www.epanorama.net/documents/l...mmer.html#120v The "typical 120V AC dimmer circuit" uses almost the same components that are on my dimmer: two diodes cap resistor pot diac triac The diodes test good one way so I wonder if either the BT137F triac or the DB3 diac are the problem. Can these be tested with a VOM? I went to the local parts store and they did not have either the triac or the diac. They did have a TNE5646 "Triac with Internal Trrigger Diac", which I purchased. This is also a 600V device and it handles 10A. Can I simply install this in place of the BT137F and jumper between the two holes on the circuit board for the missing diac? |
#10
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
"Bob Simon" wrote in message ... I went to the local parts store and they did not have either the triac or the diac. They did have a TNE5646 "Triac with Internal Trrigger Diac", which I purchased. This is also a 600V device and it handles 10A. Can I simply install this in place of the BT137F and jumper between the two holes on the circuit board for the missing diac? Pretty much. If you have a large library close by try to find a copy of a GE SCR Handbook or similar. This will explain a lot of the way these work. Will the new device fit OK? |
#11
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
I went to the local parts store and they did not have either the triac or the diac. They did have a TNE5646 "Triac with Internal Trrigger Diac", which I purchased. This is also a 600V device and it handles 10A. Can I simply install this in place of the BT137F and jumper between the two holes on the circuit board for the missing diac? You should be able to, give it a shot, worst case it won't work. |
#12
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On Wed, 21 Mar 2007 02:20:36 GMT, James Sweet
wrote: I went to the local parts store and they did not have either the triac or the diac. They did have a TNE5646 "Triac with Internal Trrigger Diac", which I purchased. This is also a 600V device and it handles 10A. Can I simply install this in place of the BT137F and jumper between the two holes on the circuit board for the missing diac? You should be able to, give it a shot, worst case it won't work. It didn't. The pot/switch also had problems. I removed it from the circuit board, squirted in some tuner cleaner, and worked the shaft. Now the pot works good mechanically and electrically but the switch is still unreliable. I hate to give up when I'm so close. Is there any hope of repairing the switch if I open up the pot? What about finding a replacement that will fit into the board? The only markings on the pot are T S on the bottom of the casing. The circut board it came from is labeled Golo. Does anyone recognize what either of these are? |
#13
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
It didn't. The pot/switch also had problems. I removed it from the circuit board, squirted in some tuner cleaner, and worked the shaft. Now the pot works good mechanically and electrically but the switch is still unreliable. I hate to give up when I'm so close. Is there any hope of repairing the switch if I open up the pot? What about finding a replacement that will fit into the board? The only markings on the pot are T S on the bottom of the casing. The circut board it came from is labeled Golo. Does anyone recognize what either of these are? If you open the switch you might be able to repair it. Worst case you can replace the pot with an ordinary one of the same resistance and then put an inline switch on the cord. |
#14
Posted to sci.electronics.repair
|
|||
|
|||
Lamp Dimmer
On 21 Mar, 14:56, Bob Simon wrote:
On Wed, 21 Mar 2007 02:20:36 GMT, James Sweet wrote: I went to the local parts store and they did not have either the triac or the diac. They did have a TNE5646 "Triac with Internal Trrigger Diac", which I purchased. This is also a 600V device and it handles 10A. Can I simply install this in place of the BT137F and jumper between the two holes on the circuit board for the missing diac? You should be able to, give it a shot, worst case it won't work. It didn't. The pot/switch also had problems. I removed it from the circuit board, squirted in some tuner cleaner, and worked the shaft. Now the pot works good mechanically and electrically but the switch is still unreliable. I hate to give up when I'm so close. Is there any hope of repairing the switch if I open up the pot? What about finding a replacement that will fit into the board? The only markings on the pot are T S on the bottom of the casing. The circut board it came from is labeled Golo. Does anyone recognize what either of these are? switches are easy to repair, they usually just need a scraping of the contact points. NT |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Can I Remove the InLine Dimmer Switch in a Floor Lamp? | Home Repair | |||
Pole Lamp Dimmer/Switch Module | Home Repair | |||
Need dimmer for 750watt lamp | Home Repair | |||
Fitting a dimmer switch to a floor lamp - No Earth | UK diy | |||
inconsistent performance from high voltage ignition coil/ lamp dimmer circuit | Electronics Repair |