When the package arrived in the mail, I thought it was a mistake. Surely an entire dimmer couldn't fit in the small box that was delivered. When I picked up the box, my suspicions were confirmed; the box was way too light to have much of anything in it and certainly not a dimmer. Or were they? The label did say it was from Lex Products, and the dimmer that was supposed to arrive is called the Slim Dimmer. What gives?
It turns out that there was an entire dimmer in the package. The single-channel Slim Dimmer from Lex Products is so small and lightweight that you might have to convince yourself that there's anything in the package.
At 5.94 inches long, 4.13 inches wide and 2.38 inches high, weighing in at 1.6 ounces, it is possibly the smallest professional dimmer on the market. But size (and weight) can be deceiving. The little package can dim up to 1800 watts of incandescent lights.
The housing is extruded aluminum, and it has no cables attached to it at all. Instead, it has a recessed NEMA 5-15 (commonly called an Edison plug) input and a flush-mount output, which makes it even easier to simply toss into your toolbox or luggage and carry it with you.
There is also a ¼-inch-20 threaded insert in the bottom of the housing to attach it to a c-clamp or grip stand.
Next to the output connector is a small round button connected to a built-in 15-amp thermal circuit breaker for circuit protection. It is a UL 1077 supplementary protection device that will carry 100 percent of the rated 15A current at an ambient temperature of 25°C. It is designed to trip within one hour at 135 percent of the rated current and within 0.3 to 1.8 seconds at 600 percent of rated current. The button is normally flush with the housing and it pops out when it trips. To reset it you simply push the button.
On the other side of the housing, there is a small, two-digit LED display and a manual fader. It indicates the current dimming level from 0 to 100. Two metal tabs, one at the top and one at the bottom of the dimmer offer some protection for the fader knob in the event that it is bumped or dropped. There is no DMX input and therefore no DMX control, only manual operation. An LED display indicates the current level of dimming when it's powered up. It's a very simple device with no On/Off switch, no external control and no choke.
That's right; the unit has no filtering or choke of any kind. That's part of the reason that it is so lightweight. Most dimmers have a choke coil to limit the rise time of the current waveform and to prevent filament sing. A choke adds to the cost and weight of the dimmer, but the trade-off is that a bigger choke is more effective at filtering out noise, making for a quieter system.
At the heart of this dimmer is a Q4040J7 triac. It is manufactured by Teccor and according to the data sheet it offers the same performance as two SCRs wired in inverse parallel fashion (back-to-back) and better performance than a standard triac.
I tested the Slim Dimmer with a 575-watt Source Four ellipsoidal and a 500-watt PAR can. The Source Four exhibited no lamp sing whatsoever, but the PAR can did. Using a Fluke 43B power quality meter, I scoped the voltage and current waveform. I looked for current overshoot, but I could see none. The unit dimmed smoothly and reliably and took up very little space in the process.
Lex Products Slim Dimmer
What It Is: A small, simple single-channel 1800W dimmer for conventional (incandescent) lamps with manual operation.
Who It's For: Anyone who needs a portable single channel of dimming including photographers, grips, theatre techs and more.
Pros: Small, lightweight, very portable, inexpensive, easy to use.
Cons: No choke can produce filament sing in some fixtures, no DMX or remote control
How Much: $300
