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--- fuss:hardware [2020/03/30 22:46] – [Fixing Stuck CD Tray] office
+++ fuss:hardware [2020/05/30 10:16] – [Creating a Molex Power Distributor] office
@@ Line 236: / Line 236: @@
 Shorten pins 31 from 34, and 26 to ground.
+====== Creating a Molex Power Distributor ======
+It appears that molex power distributors are tough to come by, perhaps due to the fact that all hardware is standardized and designed to reduce the number of cables necessary to wire a computer. When building a custom computer such as an Amiga with non-standard hardware, the cabling can become pretty complex such that the airflow within the chassis may end up greatly reduced and thereby increase the heat on various components.
+Using a simple blank PCB and 1-to-1 connections, as well as some magic putty a molex power distributor can be created that will provide power to various components from the same power outlet.
+{{fuss:fuss_hardware_molex_power_distributor_front.png?512}}
+{{fuss:fuss_hardware_molex_power_distributor_back.png?512}}
+{{fuss:fuss_hardware_molex_power_distributor_top.png?512}}
+Magic putty is designed to be sanded down such that a nice finish can be given to the component after everything is checked to work correctly.
+Note that the connections between the molex pins have to be perfect and continuity can be verified using a multimeter, preferably by testing with the built-in continuity tester as well as measuring resistance between the pins up to a few megohms.
+====== Creating an Affordable Tray Rack Fan  ======
+Tray rack fans are meant to be inserted between the various layers of servers in a rack cabinet. Unfortunately, tray rack fans seem to be rather expensive contrasted with how they are designed to operate: a rack fan consists more or less of 4 standard $140mm$ PC fans, perhaps a switch, a potentiometer or a thermal sensor to regulate the speed. All of this comes at more or less USD100 and the price most likely gets inflated due to the equipment being considered "industrial" and meant for enterprises.
+===== Requirements =====
+  * 19" Tray - USD15,
+  * 140mm PC fan with 2 or 3 pin headers - USD 6 / piece, 24 USD,
+  * $220V$ to $12V$ step down converter,
+  * soldering, drilling equipment, etc.
+Optional:
+  * [Optional] PCB
+  * [Optional] IC pin headers
+Overall: about USD50.
+===== Design =====
+holes are drilled into the tray and the fans are mounted using nuts and screws onto the tray. The fan connectors are then connected to IC headers on a PCB that is fastened to the tray. A hole is drilled into the side of the tray and leads are drawn to the step down voltage converter in order to feed the fans. The PCB design just needs to pull $12V$ and $GND$ from the fan headers whilst ignoring the last pin which is the tachometer output signal. If a more complex design is required then perhaps the tachometer output signal could be read by an ESP microcontroller in combination with a thermal sensor.
+However, most of the suggested complexity is not required and even the PCB can be left out at the cost of severing the connections between the fan headers and then connecting the leads directly to $12V$ whilst making sure that the fans are coupled in parallel.
+===== Results =====
+{{gallery>fuss:hardware:affordablerackfantray}}