NL405 - Width/Delay
Introduction
The
NL405 WIDTH/DELAY
is a digitally controlled pulse duration generator and is used
to produce precise pulses of adjustable duration with high accuracy and repeatability.
The
NL405
produces TTL logic output pulses (of both polarities) that have a duration set
using three decades of thumbwheels and a seven (7) position range switch. It also
features a press to start button, LED indication of an output and a separate logic output
signal at the end of the defined WIDTH time. It was designed as a replacement for the
NL401 and in most places where the NL403 would have been used.
The
NL405
can be triggered off either positive or negative-going edges of the input pulses
and the
NL405
is capable of 100% duty cycles. An external push to make switch can be
used when -ve edge triggering is selected.
In the “FIXED WIDTH” mode, the
NL405
produces an Output pulse as specified by the
front panel controls; In the “RE-TRIGGER” mode, any valid Input trigger arriving whilst the
Output is active will restart the timing and therefore extending the Output pulse duration.
As long time periods can be generated (999 seconds is over 16 minutes) any change in
position of the rotary range switch will stop the current Output and inhibit further input
triggers for 450 ms.
The “DELAYED” Output socket provides a short duration pulse (set internally) that is
produced at the end of the timed WIDTH pulse. This provides a trigger-out after the set
Delay time.
The
NL405
can be used for digital control of pulse duration or for introduction of a delay to
a trigger pulse. The logarithmic or exponential nature of the many biological responses
make the very wide continuous adjustment (from µs to minutes) particularly beneficial.
Specification Summary
Input:
:
TTL pulse. Input is 1 TTL load.
Trigger edge
:
Positive or Negative, selected from front panel
Manual
:
Push-button, operation on push.
Output (Width)
:
TTL. Output will drive 10 loads.
Polarity
:
Both active-high and active-low sockets
Range
:
1 µs to 999 s
Control
:
001 to 999
Multiplier
:
1 µs, 10 µs, 100 µs, 1 ms, 10 ms, 100 ms, 1 s.
Accuracy
:
±0.5%
Delay from Trigger In
:
<200 ns
Indicator
:
Amber LED on for approximately 100 ms for each pulse
Output (Delay)
:
TTL. Output will drive 10 loads.
Polarity
:
Active-high
Duration
:
0.5 µs, 1.5 µs, 5 µs
±20%
50 µs, 150 µs, 500 µs ±10%, by on-board jumpers.
Output
Mode
:
Fixed Width or Re-Triggered, selected from front panel
Reset/Inhibit
:
450 ms ±20%, after change of rotary range control.
Rear connections to the motherboard allow Input and Output interconnections between this and other logic
modules without the need of front panel cables.
Users Manual
NeuroLog™ System
NL405
Digitimer Ltd
Page 1 of 5
Copyright © 2003
E-mail:
Tel:
+44 (0)1707 328347;
Fax:
...373153
Website:
www.digitimer.com
