HP A Series User Manual

1-10 OPTIONS 103
T11 Options are factory modifications of a standard
instrument that are requested by the customer. The
following options are available for the instruments
covered by this manual. Where necessary, detailed cover¬
age of the options are included in the manual.
OPTION NO. DESCRIPTION
011 Overvoltage Protection "Crow¬
bar": A completely separate circuit
for protecting delicate loads against
power supply failure or operator
error. The crowbar circuit monitors
the output voltage and within
10 Msec imposes a virtual short-circuit
(conducting SCR or triac) across the
power supply output if the preset
overvoltage margin is exceeded. The
crowbar circuit is contained on a
printed wiring board that is mounted
inside the power supply. The activa¬
tion (trip) voltage of the crowbar is
adjustable (screwdriver adjustment)
over the following minimum range:
from -i-0.5 Vdc above minimum rated
output voltage to +2 Vdc above maxi¬
mum rated output voltage.
101 220 Vac, single phase input: Supply
is normally shipped with a 120 Vac
(nominal) transformer. Option 101
replaces this transformer with a
220 Vac (nominal) transformer and
allows operation from a 190-233 Vac,
48-63 Hz single phase input.
102 240 Vac, single phase input: Supply
is normally shipped with a 120 Vac
(nominal) transformer. Option 102
replaces this transformer with a
240 Vac (nominal) transformer and
allows operation from a 208-254 Vac,
48-63 Hz, single phase input,
120 Vac/240 Vac, single phase in¬
put: Supply is normally shipped with
a 120 Vac (nominal) transformer.
Option 103 replaces this transformer
with a 120 Vac/240 Vac (nominal)
multi-tap transformer and allows field-
changeable operation from 104-127
Vac or 208-254 Vac, 48-63 Hz single
phase input.
104 System Control: This option allows
the user to control the supply's over¬
voltage protection "crowbar" circuit
as well as output voltage. The 104
option includes the same internal, ad¬
justable overvoltage protection crow¬
bar as provided with the 011 option.
In addition, the 104 option crowbar
includes external (from a rear term¬
inal strip) pulse control capability
that allows the crowbar to be either
externally triggered or which provides
an output pulse to indicate that the
crowbar has triggered. The crowbar
pulse specifications are:
Input Trigger Pulse:
Voltage: 8 — 15 V
Width (between 90% point at
leading edge and 10% point
at falling edge); 5 jusec —
2 msec
Output Pulse:
Voltage; 2 - 12 V
Width (between 90% point at
leading edge and 10% point
at falling edge): 2 — 20Msec
Load Impedance; 1 Kii (min.)
In addition to the crowbar trigger
external access, the 104 option also
includes access (from a rear terminal
strip) to the summing point of the
supply to enable the dc output volt¬
age to be remotely programmed to
zero (±15 mVdc max.) with a contact
closure.
1-3

HP A Series Specifications

General

Brand	HP
Model	A Series
Category	Power Supply
Language	English