HP 214B User Manual

Operation
3-15 GATE MODE
3- 16 With gate mode selected, the internal repetition rate
generator is turned on either by applying an external signal
to the EXT INPUT connector or by operation of the MAN
pushbutton .
3-17 If an external signal is applied, then pulses occur at
the 214B output when :
a) with po sitive slope selected, the ex ternal signal is
more positive than the selected trigger level (selected
by EXT INPUT LEVEL control). See figure 3-2 .
b)
with negative slope selected, the external signal is
more negative than the selected trigger level. See
figure 3- 2.
S£:lECTf l.) THI( ;GER l!:. Vl L ~
l; ATf- Sl l ;'\Jt'\l ---1
.'llU OU TPU T
:POS $1 OPE ,.1. <, hi '
J1'm OUTPUl
-NEt; SL OPE ,,·1.·, (,·d
Figure 3-2 214B Outputs in Gate Mode
L .
I n either case, the effective period of the gate signal should
be greater than the period selected at the RATE /PER I OD
controls . Also, as in NORM trigger mode, pulse position
and pulse width settings should be less then PERIOD
s etting to avoid timing errors.
3- 18 When using the MAN pushbutton to generate output
pulses, the SLOPE slide switch must be set to MAN, then
214B output pulses occur for as long as the MAN push-
button remains pressed. Other front panel controls are set
to obtain the desired pulse characteristics e.g. frequency,
delay, width etc .
3-19 PULSE POSITION
3- 20 The output pulse of the 214B can be delayed or
advanced with respect to the trigger output, according to
the setting of DELAY / ADVANCE slide switch. In either
case, the range is selected via the PULSE POSITION push -
button row, and exact setting accomplished via the PULSE
POSITION ca
librated vernier.
3-
21 In the event of the selected delay/advance being
greater
than the selected period, the TIMING ERROR LED
will be
illuminated and remain illuminated as long as th is
erro r relationship exists. (Note: the TIMING ERROR LED
funct i on s only in NORM mode) .
3-22 For DOUBLE PULSE operation, the PULSE POSI-
TION
controls are used to s et the delay between the start of
3-2
Model 214B
the first pulse and start of the second pulse. In this mode,
the following timing conditions s hould be observed for a
true output:
a) the pulse position setting less than the selected
period. (Note : in this mode, range 1 On-.l u is not
specified)
b)
the minimum separation between the first and second
pulse (see figure 3- 3)
is the minimum setting of the
selected pulse position range e.g. in 1 m· -lOm pulse
position range, minimum separation is 1 ms.
:-
~ S EP A R AT I ON . ~
I I
I
PU LS E
P
OS ITI ON
,
- .. ---
;- : ... __ -- . --- PER IOD
r--,
I I
I I
I
~I
I
'----
Figure 3- 3 . Timing parameters in Double Pulse Mode .
3-23 DUTY CYCLE
3-24 Duty cycle is defined as the percentage ratio of pulse
width to pulse period . With the 214B, a DUTY CYCLE
pushbutton is provided, whereby:
if released, the WI DTH pushbutton row is operational,
and the vernier provides continuous width adjust -
ment within the selected range. In this case, the width
remains constant when the period is changed, hence
duty cycle var ies with frequency .
if pressed, then only the DUTY CYCLE range push-
buttons are operational, and the vernier provides
continuous adjustment of duty cycle within the
selected range. Once set, the duty cycle remains
constant in the event of a frequency change. This
feature is referred to as Constant Duty Cycle Mode
of operation .
3-
25 When the DUTY CYCLE pushbutton is released, the
pulse width is set via the WI DTH pushbutton row and related
vernier, the duty cycle then being operator - calculated by
relating
this time to the output pulse period. The maximum
duty cycle in this case (whether internal or external trigger)
is :
at least 10 % for the 30-100 V amplitude range
at least 50 % for all other amplitude ranges (up
to a max . pulse width 10 ms)
If the maximum allowed duty cycle is exceeded, the 214B
output will be automatically disabled and thus safeguarded
from overload .
The disabled condition is generally indicated by the
OVE R LOAD LED. At rates above 4 MHz, however, the
Scans by ArtekMedia => 2009

HP 214B Specifications

General

Brand	HP
Model	214B
Category	Portable Generator
Language	English