The MOTM-900 is a 3U wide, low-noise linear supply
that accepts AC line inputs from 100 to 240VAC 50/60Hz (jumper
selected) and outputs +-15VDC at 800ma. The easy-to-change
fuseholder accepts standard 5mm x 20mm fuses. Instead of noisy
3-terminal regulators, the MOTM-900 uses a 723-based design, using a
pre-assembled and tested Power-One supply. This makes assembly of
the kit fast and almost fool-proof.
Each MOTM module uses a 4-pin connector called an MTA-156. These
are "industry standard" connectors that have been in use for over 20
years. The MOTM-900 contains a special pc board that has 12
individual MTA male connectors. A 4-conductor, 18ga wire harness
(part number PWR-20, included with each kit) connects the module to
the MOTM-900. In this manner, a "star" power distribution scheme is
used for lowest noise and avoiding ground loops.
Specifications for the supply include:
- LINE REGULATION: +-0.05% for a +-10% AC input change (very
likely!)
- LOAD REGULATION: +-0.05% for a 50% load change (highly
unlikely!)
- RIPPLE: 5mv pk-pk MAX. <1mv pk-pk typical
Since the average MOTM module draws 20ma from each supply, at 65%
rated capacity (to keep the heat down) the MOTM-900 can power over
20 modules. An additional power distribution board can be purchased
(see the catalog) to supply over 12 modules.
In the past, "homebuilt" synthesizers with 3-terminal regulators
have suffered from noise, hum, and crosstalk. The MOTM-900 design
and power distribution system eliminates these problems, and will
provide years of trouble-free service.
;)
;)