Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  ..  5    7
Author: Subject: Electrical Furnace Contruction - My design and implementation
watson.fawkes
International Hazard
*****




Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 5-2-2012 at 08:42


Quote: Originally posted by Endo  
Well, I found 1000Watt Dimmers for $7.50 each online. [...] I dug through some stuff and found an old heat sink from an Athalon Thunderbird processor and drilled it to mount the triac.
This is really good practical modification. I blurbed it in another thread on controlling heating mantles. I suggested there using this in conjunction with a dedicated ammeter on the panel.

Could you provide us all the exact brand and model number of the dimmer you used? It would be good to know, if ordering one of these by mail, that it has a triac of the right packaging to make this easy. The RD91 package the triac is in makes the mod much easier, particularly over remotely mounting a TO-220 package or worse yet, one of the PCB-only packages. See the spec sheet for the BTA25-600B to see that it's certainly possible to get unlucky on the device packaging.
View user's profile View All Posts By User
Endo
Hazard to Others
***




Posts: 120
Registered: 5-1-2006
Location: USA
Member Is Offline

Mood: Cold

[*] posted on 6-2-2012 at 18:29


The model of the dimmer is LUXDM1000-02L The manufacturer name on the packaging is SecurElectric Corporation.

http://www.homelectrical.com/single-pole-1000w-slide-dimmer-...

The back cover is held on with two screws and comes off easily. It comes with four holes at the top and four at the bottom, so I didn't have to drill to get the three new wires out.

To get the Triac out I used a dremel tool with a cutoff wheel to cut the top off of the pop rivet holding the triac to the heatsink (A small copper plate) and through the aluminum facing. A few minutes with the solder iron got it loose, then just added the wires and pulled them through the pre-drilled holes in the case. Two were really easy because they matched up with some solder joins for other large wires. The third connection was a fairly small patch on the board to hook the wire but easily doable.

Oh I wasn't 100% but from the documentation I could find on the Triac I belive the back plate of it must be grounded. I just drilled a second hole and used a screw to hook a ground wire up to the heatsink.

Hope this helps if someone else wants to try it.

Dimmer.JPG - 82kB
View user's profile View All Posts By User
watson.fawkes
International Hazard
*****




Posts: 2793
Registered: 16-8-2008
Member Is Offline

Mood: No Mood

[*] posted on 6-2-2012 at 18:52


Quote: Originally posted by Endo  
The model of the dimmer is LUXDM1000-02L [...]

Oh I wasn't 100% but from the documentation I could find on the Triac I belive the back plate of it must be grounded. I just drilled a second hole and used a screw to hook a ground wire up to the heatsink.

Hope this helps if someone else wants to try it.
Thanks for the model number. The spec sheet for the triac states the following:
Quote:
By using an internal ceramic pad, the BTA series provides voltage insulated tab (rated at 2500V RMS) complying with UL standards
In other words, the metal mounting tabs on the case are electrically isolated from the triac connections or the device itself. Hooking up a bonding wire to the heatsink is still the right thing to do. The heat sink is a conductor whose potential would otherwise float. It's always right bond such a conductor to ground. This bonding wire doesn't ordinary carry current; it's for conducting fault current to ground so that other protection devices operate.

What has helped me most is knowing there's a 25A triac hiding inside that consumer device. Single unit quantities for that model triac is more than $5, so why not buy the whole assembly? I've been thinking I'll make a general-purpose dimmer box with it with its own outlet, since it would be able to handle anything that the 15A circuit on a typical wall outlet would. My guess is that a similar 600W dimmer unit has a 15A triac inside, for that matter.
View user's profile View All Posts By User
 Pages:  1  ..  5    7

  Go To Top