May 28, 2003 -- by Mike Chin
While multiple fan controllers are all the rage with all sorts of brands and companies getting into the action, speed control devices for single fans remain very useful in many PCs. Often, in very quiet PC systems, one or two fans are set to a preferred, ideal speed then left more or less forgotten. There is no need for external fan speed adjustments. This article is a roundup review of 3 such devices by Zalman, who has to be considered the king of simple fan speed controllers.
ZALMAN RC56 "NOISELESS CONNECTOR"
This little doo-hickey is not even sold separately. It is simply included with some of its products, such as the CNPS3000-Plus flower heatsink and the FB-165 fan & bracket VGA cooling package. It may have first appeared as part of the CNPS3000 flower heatsink & fan package going back some 2 years.
It is an extension lead for use between a motherboard header and a standard 3-pin fan with a 55 ohm resistor in the positive (red) lead. (A 1W or 2W resistor, I think.) There is a pass-through for the fan tach lead, so speed reporting functionality is not lost. The resistance drops the voltage seen by the fan.
The exact amount of the voltage drop depends on the fan's impedance. With the 0.2A Zalman fan, the drop is around 6V, which means the fan runs at 6V. The resistor dissipates 0.55 watts, and gets a bit warm.
The voltage drop with the 0.07A Panaflo 80mm "L" fan is only a bit over 3V. The Panaflo gets nearly 9V -- a bit too high for many of us, but still not useless in many apps.
For those who are not solder-shy, it's a simple matter to replace the resistor with one of different value to customize it for a specific application. Surely a simpler matter than sourcing the parts (just try finding one or two of those 3-pin connectors!) and building it from scratch. The RC56 remains a useful little tool.
ZALMAN FAN MATE 1
The Fan Mate 1 replaced the RC56 in most Zalman heatsink packages a little over a year ago. Unlike the RC56, the Fan Mate 1 is sold on its own in a little plastic package that tells much about Zalman's growing expertise in retail packaging. It is not anything for ecologist to applaud, but retailers are probably quite happy with Zalman's plastic display package prowess. It is typically sold for US$6~8.
The functionality of this device is very similar to the older RC56, but this time Zalman went a couple steps higher up the technology ladder: The Fan Mate 1 is an active voltage controller that provides continuously adjustable voltage from 5V to 11V. Anyone who has bought a popular Zalman heatsink fan in the past year will be familiar with the Fan Mate 1.
Zalman's specifications :
- Dimensions (mm): 200(L) X 21(H) X 23(W)
- Weight (g): 20
- Output Voltage: 5 ~ 11 V +-2%
- Allowable Wattage: 6W or lower
The internal construction of the Fan Mate 1 shows a little variable resistor working in conjunction with a power transistor that's mounted on a wee piece of aluminum extrusion that acts as a heatsink. The 6W capacity is much more than the simple resistor can handle. It means that even the gale-howling monster fans favored by overclockers can be handled, although it's difficult to see what the point of such an exercise would be.
Fan Mate 1 works exactly as intended but has a couple of obvious flaws associated with the little knob:
- It is very small, and has little effect in the first half turn (going counterclockwise). Most of the voltage drop seems to occur in the last half portion of the rotation, which makes the little knob even more fiddly than it has to be.
- It has no marking or scale, which means one sets the voltage / fan speed either by ear or thermal monitor rather than any visual cues.
Fan Mate 1 single-handedly achieved a mass introduction of the concept and experience of making a fan run slower, even tweaking its speed, to reduce noise to PC enthusiasts. For that mindshare win among PC users everywhere, Zalman deserves some kind of SPCR medal of honor.
ZALMAN MULTI-CONNECTOR 1
The Multi-Connector, Zalman's final entry in the category of simple fan controllers actually barely qualifies by not even containing a single switch (a controller with no controls!?), and by providing voltage for up to 4 fans. It still belongs in this roundup. It is the simplest of devices, simpler even than my DIY 12/5V switch, but with a similar function. In Zalman's own words...
The Multi-connector, included free with every Zalman power supply, [provides] +5V or +12V power to any additional fans that a user may wish to install. Connect it to the power supply's output connector and simply attach the fans to the 3-pin connectors at the other end.
The photo above is self-explanatory to those who mess about inside computers. The connector on the right goes to a standard 4-pin peripheral power plug from the PSU, which carries both 12V and 5V lines. The two black connectors carry 12V via the yellow wires to standard 3-pin fans; the two white connectors carry 5V via the red wires to standard 3-pin fans. There is no facility to retain RPM monitor except by the user's own ingenuity.
As 5V is the target fan voltage for most silent PC enthusiasts, this is an incredibly useful and inexpensive device. What more can be said? Just one thing: Zalman makes the MC1 available separately in another slick but non-ecological retail package. It typically sells for ~US$2.50.
Zalman products are available at Zalman USA, Silicon Valley Compucycle and Sharka Corp.
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