Model 405C Sect.III Page 3
have no effect. The first output pulse from the tion 0 (wrong range), the Hundreds Binary lets the
Hundreds Counter switches the Hundreds Binary Decimal Shift Thyratronfire if triggered and closes
back to condition 0. Succeeding pulses have no the Print Command Gate.
effect. Therefore, if the measurement ends with
the Hundreds Binary in condition 1, the range is When the Ramp Gate Multivibrator returns to its
correct; if the measurement ends with the Hundreds stable condition and closes the Ramp Gate, it ap-
Binary in condition 0, the range is wrong. plies a positive pulse to the Decimal.Shift Thyra-
tron and a negative pulse to the Print Command
There is a direct reset line from the Delay Multi- Gate. If the range is correct, the negative pulse
vibrator to the Hundreds Binary (not shown in passes through the Print Command Gate to be used
Figure 3-1); so the Delay Multivibrator directly as a trigger for a remote recorder. The Decimal
resets the Hundreds Binary in the event the Tens Shift Thyratron is held off. If the range is wrong,
Binary is in condition 0 and the Hundreds Binary the Print Command Gate is closed, but the posi-
in condition 1, should this combination occur. Also, tive pulse fires the Decimal Shift Thyratron. The
on the *. 999 v range, when no logic pulse is avail- Decimal Shift Thyratron then shifts the instrument
able from the now by-passed Tens Binary, this to the next more positive range (by moving Step-
line serves to reset the Hundreds Binary to con- ping Switch Kl one step) and triggers Relay Control
dition 0, where it remains. However, if the range Multivibrator V9 to start another measurement.
is too low, an output pulse will be produced by the
Hundreds Counter which immediately resets the When triggered, the Relay Control Multivibrator
Hundreds Binary to condition 1. triggers Sampling Rate Thyratron V8. The Sam-
pling Rate Thyratron then cannot fire during a
measurement started by the Decimal Shift Thyra-
3-7 DECIMAL SHIFT CONTROL tron.
The Hundreds Binary determines whether or not
the 405C shifts range by controlling Decimal Shift To prevent continual recycling when the 405Ameas-
Thyratron V11 and Print Command Gate CR17. ures voltages from 4.099 to -0.099 volt, the Hun-
When in condition 1 (correct range), the Hundreds dreds Binary is reset to condition 1 on the +. 999
Binary holds the Decimal Shift Thyratron off and and -. 999 volt ranges. Thus the instrument shifts
opens the Print Command Gate. When in condi- from these ranges only after off-scale counts.
00518- 1 |
ACEC
HEWLETT-PACKARD
