Dimmer Pack Disposal
- Thread starterMegan Cowher
- Start date
JD
Well-Known Member
Probably with a little more info someone would be glad to grab them. Most of them were blue boxes with 6 dimmers in them, either 2.4kw or 3.6kw per channel. Convection cooled. Output connectors were either stage pin, Edison, or just a terminal strip. Control voltage was 0-10 volts. They were incredibly reliable, and with the proper DMX to analog interface would work fine with today's systems.
Tell us a bit more of what these are configured with, or get an interface and put them to work
Tell us a bit more of what these are configured with, or get an interface and put them to work
James Gardner
Member
Depending on more info, we might be interested in taking them off your hands Megan.
Megan Cowher
Member
Megan Cowher
Member
They are functional as well
James Gardner
Member
JD
Well-Known Member
DFD makes them, but there are a ton on the market. Basically, DMX in and 0 to 10 volts analog output.
Looks like one of the rectifier fuses is missing along with the cap. You can check another channel, but if I remember they take KAA or KAW 30 amp fuses. The breakers provide the 20 amp protection, but the special fuse provides another layer of protection for solid state devices.
Example: https://octopart.com/kaw-30-cooper+bussmann-12944204
Looks like one of the rectifier fuses is missing along with the cap. You can check another channel, but if I remember they take KAA or KAW 30 amp fuses. The breakers provide the 20 amp protection, but the special fuse provides another layer of protection for solid state devices.
Example: https://octopart.com/kaw-30-cooper+bussmann-12944204
STEVETERRY
Well-Known Member
Fuses were KAW-A-35.
Original SCR's were wimpy Motorola 35A devices (MCR 3935, I think) with a very low I-Squared-T rating. A short circuit often took out an SCR as well as the fairly expensive fuse. Later units used an International Rectifier SCR with an I-squared-T of about 700 amp-squared seconds. These were bullet-proof and made the fuse redundant.
ST
Megan Cowher
Member
JD
Well-Known Member
I thought the 35's were on the 3.6k dimmers and the 30's were on the 2.4k dimmers? Not sure as it was 30 years ago!
I believe they used the same SCR on both models, so the 2.4k dimmer had a bit more headroom.
The trickiest part may be if the fuse holder cap is missing. They are hard to find these days, esp the screw on type.
STEVETERRY
Well-Known Member
I thought the 35's were on the 3.6k dimmers and the 30's were on the 2.4k dimmers? Not sure as it was 30 years ago!
I believe they used the same SCR on both models, so the 2.4k dimmer had a bit more headroom.
The trickiest part may be if the fuse holder cap is missing. They are hard to find these days, esp the screw on type.
The fuse holder is a Bussman HPC. They are still pretty available, for example:
http://www.ebay.com/itm/Bussman-HPC...-x-1-1-2-fuse-FNQ-R-ATQ-R-KTK-R-/400356365852
A trickier part will be the breakers on the early packs. These were Heinemann 0911 units, long discontinued--and very prone to contact pitting failures. They were changed to Airpax or Heinemann E-frame breakers in later units, but the mounts are not compatible from early to later models.
I find it amusing that I had the part number of the fuse holder just pop into my brain--I must have ordered a lot of replacements!
ST
JD
Well-Known Member
Those holders were used on the EDI SCRimmeretts too. (Probably other dimmers of that era) About a year back someone called me looking for a cap for one, thought nothing of it until I tried finding one. There are still some HPC holders on the market, but bayonet not screw. I had a Parts draw with 4 and ended up sending them one. Now I have 3.
Rectifier fuses fell out of use as solid state devices became more durable. Funny how those things disappear and you never even think about them until one day you notice they are gone! I used to pay about $1.50 for one of those KAW fuses. Yesterday, I saw they are now $30 !
So bottom line, my old parts tray is probably worth a fortune to a museum! Still have the caps. They are in the draw right next to the diodes for the Super Troupers.
Rectifier fuses fell out of use as solid state devices became more durable. Funny how those things disappear and you never even think about them until one day you notice they are gone! I used to pay about $1.50 for one of those KAW fuses. Yesterday, I saw they are now $30 !
So bottom line, my old parts tray is probably worth a fortune to a museum! Still have the caps. They are in the draw right next to the diodes for the Super Troupers.
If I wasn't on the other side of the continent, I'd be tempted.
