TRACO  Startup  Delay
          -----------------------

                                             Rev. 22-July-2026


Between the time when input power is applied to the TRACO
converter until the time when its output voltage begins to
ramp up - we need to introduce a delay in the range of some
10s of msec up to 1 or 2 hundred msec.

We need to do this in order to allow the significant current
spike from  charging the Main Cable and the Power Input Filters
to fully die away before significant current draw by the TRACOs
actually begins.

Such a delay in the TRACO startup is easily introduced by
connecting a capacitor in the range of a few to a few 10s
of uFd between the TRACO's  Enable pin  (aka Remote On/Off
pin)  and its  -Vin  power input pin.

The scope shot shows the startup delay caused by a 2 uFd
capacitor between these pins.

 - Yellow  Ch #1  shows the 96 Volt power input to the TRACO
   which turns ON almost instantly when a toggle switch is
   closed.

 - Blue  Ch #2  shows the voltage across the 2 uFd capacitor
   which is between the Enable pin  (+ side of the cap)  and
   the  -Vin  power input pin  (- side of the cap).  The
   voltage across the cap reached a value of about 8 Volts.

 - Green  Ch #4  shows the ramp up of the 5 Volt output from
   the TRACO which starts about 32 msec after the input power
   is applied.  The 5 Volt output ramp up takes a little over
   2 msec.


More details are in the DK Rev B Design log book in the
entry for  21-July-2026.