Global Specialties 1305 - Manual - Manual (Page 8)

to the negative terminal), the diode will conduct, shunting
current across the output t erminals to the forward
voltage drop of the diode. This diode protects the series
transistor and the output electrolytic capacitors.
4.5 OUTPUT CAPACITANCE :
Internal capacitor connected across the output terminals
of the power supply, helps to supply high current pulses
of short duration during constant voltage operation. Any
capacitance added externally will improve the pulse
current capability, but will decrease the safety provided
by the constant current circuit. A high current pulse may
damage load components before the average output
current is large enough to cause the constant current
circuit to operate.
The effects of the output capacitor during constant
current operation are as follows:
a. The output impedance of the power supply decreases
with increasing frequency.
b. The recovery time of the output voltage is longer for
load resistance changes.
c. A large surge current causing a high power
dissipation in the load occurs when the load resistance is
reduced rapidly.
4.6 REVERSE CURRENT LOADING :
Active loads connected to the power spply may actually
deliver a reverse current to the power supply during a
portion of its operating cycle.
An external source cannot be allowed to pump current
into the supply without loss of regulation and possible
damage to the output capacitor. To avoid these effects, it
is necessary to preload the supply with a dummy load
resistor so that the power supply delivers current through
the entire operation cycle of the load device.
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PCB Components ZSDT-CT/05 PCB
=======================================================================
Ref Designator Value
========================================================================
R26 820E, MFR, 1/4W, 5%
R27# 330K, MFR, 1/4W, 5%
R28# 39K, MFR, 1/4W, 5%
R29# 180K, MFR, 1/4W, 5%
R30 1K, MFR, 1/4W, 5%
R31 15E, MFR, 1/4W, 5%
R32 6.8K, MFR, 1/4W, 5%
R33 15K, MFR, 1/4W, 5%
R34 6.8K, MFR, 1/4W, 5%
R35 15K, MFR, 1/4W, 5%
R36 1K, MFR, 1/4W, 5%
R37 2K, MFR, 1/4W, 5%
R38 1K, MFR, 1/4W, 5%
R39 1K, MFR, 1/4W, 5%
R40 4.7K, MFR, 1/4W, 5%
R41 330K, MFR, 1/4W, 5%
R42 100E, MFR, 1/4W, 5% (I CAL)
R43* 3.9K, MFR, 1/4W, 5% (I CAL)
R44 1K, MFR, 1/4W, 5%
R45 1K, MFR, 1/4W, 5%
R46* 10K, MFR, 1/4W, 5% (V CAL)
R47* 100E, MFR, 1/4W, 5% (V CAL)
R48 2K, MFR, 1/4W, 5%
R49 Shorting Link
R50 Shorting Link
R51 10E, MFR, 1/4W, 5%
R59 10E, MOR, 2W
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