My dual cab unit started out as a unit that comprised of two linearly
regulated supplies that had provision for computer controlled output
levels, which actually got built and were briefly used. I soon ripped
those out and exchanged them with pulse width modulated (PWM) supplies that
are based on a old, standard design. However, I added the National
LMD18200 55V/3A H Bridge at the output of each instead of the
tradional single MOSFET output transistor. These H bridges offer
such features as braking, output current sensing, directional control,
and an error flag. Finally, I ripped out the cab B panel-mounted
controls and added a portable throttle with adjustable momentum and
breaking.
These supplies are capable of 16V at 2A, running at ca. 85Hz and can
modulate between 0 and 100%. The cab also privides 14VAC at 2A for
turnouts and accessories.
Cab1
- Page 1 - Transformer and rectifiers
Cab2
- Page 2 - Old linear regulators
Cab3
- Page 3 - Old computer controlled regulator
Cab4
- Page 4 - Front panel layout and rear barrier strip pinout
Cab5
- Page 5 - Old computer controlled voltage output levels, etc
Cab6
- Page 6 - Transformer pinout
PWM1
- Page 1 - Single channel schematic
PWM2
- Page 2 - Dual channel PCB layout, separate layers
PWM3
- Page 3 - Dual channel PCB, all layers superimposed
PWM4
- Page 4 - Bill of materials
