To aid in the understanding of the capabilities of the Model 8010 Pulse Generator, this section describes the operation of the controls and connectors present on the Model 8010. This instrument conforms electrically and mechanically to specifications for NIM (nuclear instrument modules) per AEC report TID-20893, Rev. 3.

2.2 FUNCTION OF CONTROLS & CONNECTORS

2.2.1 POWER CONNECTOR

Power is applied to the Model 8010 through this connector. Pin 34 is ground. Pin 16 is +12V. Pin 17 is -12V. Pin 10 is +6V.

2.2.2 POWER SELECT

The Model 8010 may be operated from either +/-12V or +/-12V and +6V supplies. With only +/-12V supplies, the power requirements are 380mA for +12V and 100mA for -12V. With +/-12V and +6V supplies, the requirements are: 80mA for +12V, 100mA for -12V, and 300mA for +6V. The selection of this power option is accomplished by a slide switch mounted on the pc board. In order to operate this slide switch, the right-hand side cover must be removed.

2.2.3 FREQUENCY

This concentric switch and potentiometer combination provides the pulse repetition rate control. The switch selects one of eight internally generated repetition rate ranges or an EXT/S.C. range. With a vernier frequency control mounted concentrically to the range control, a continuous adjustment of the internal rep rate frequency from 1Hz to 50MHz is provided. In the EXT/S.C. range, only an EXTERNAL TRIGGER or the SINGLE CYCLE pushbutton will initiate a pulse cycle.

2.2.4 EXTERNAL TRIGGER AND SINGLE CYCLE

With the FREQ switch in the EXT/S.C. position, an EXTERNAL TRIGGER signal or SINGLE CYCLE pushbutton will start a pulse cycle. A single pulse cycle is initiated by the depression of the SINGLE CYCLE pushbutton on the front panel.

The Model 8010 can be externally triggered from 0Hz to 50MHz via signals at the EXT TRIG connector. Signals should be at least +1V, with a rate of rise less than 3 V/uSec. The input impedance at the EXT TRIG connector is 50 Ohm.

2.2.5 GATE-SYNCHRONOUS/ASYNCHRONOUS
With proper signals into the EXT GATE connector, output and trigger signals can be gated on and off. A low level or short circuit at the EXT GATE connector results in no output or trigger pulses present at their respective con- nectors. An open circuit or a signal greater than +1.5 V at the EXT GATE connector results in the proper trigger and output pulses at their respective connectors.

The SYNC/ASYNC toggle determines whether the gated outputs and triggers will be synchronized with the gating waveform. In the SYNC mode, the internal clock is enabled by the gating signal. The output pulse train begins with the gate signal. For fixed width gate signals, a constant number of outputs will be gated on for a given internal frequency.

In ASYNC mode, the internal clock free runs and the signals from the clock are gated. Thus, the beginning of the gate may occur before, during, or after the occurrence of an output pulse.

Gate signals will gate SINGLE CYCLE, internal FREQUENCY, and EXTERNAL TRIGGER signals. The gate will operate in ASYNC mode on any of these trigger sources. In SYNC mode, the gate will operate on SINGLE CYCLE or internal FREQUENCY signals.

2.2.6 TRIG OUT
This connector provides a trigger signal to which pulse delays are referenced. The 50% point of the positive sloped edge is the zero delay point. The trigger level is about +1V into 50 Ohm. The TRIGGER OUT circuitry is a current source of about 20mA that will sat- urate into high impedances at a level of about +4.5 V. A 50 Ohm load should be used when working with narrow delays. With an internal clock, the output is a square wave. In the EXT/S.C. model. if an EXTERNAL TRIGGER is applied, the TRIGGER OUT follows the EXTERNAL TRIGGER width; if the S.C. pushbutton is pressed, the TRIGGER OUT is 70 nSec wide.

2.2.7 DELAY

This concentric switch/potentiometer control determines the delay between the leading edge of the trigger signal and the leading edge of the output pulse. Together with the nine coarse ranges, the vernier control provides for continuous adjustment of delays from 25nSec to 1 Sec.

2.2.8 WIDTH
This concentric switch/potentiometer combination controls the width of both output pulses. The output pulse begins at the end of the delay time and ends after a time determined by the WIDTH controls. The nine coarse ranges, together with the vernier control, provide for a continuous width adjustment from 20nSec to 1 Sec.

2.2.9 SINGLE PULSE/DOUBLE PULSE
The S.P./D.P. toggle switch selects single pulse or double pulse operation. In the SINGLE PULSE mode, the output pulse starts after the DELAY time and lasts for a duration determined by the WIDTH controls.

In the DOUBLE PULSE mode, two pulses occur: one starts at essentially zero delay (at the positive slope of the trigger signal) and lasts for a duration set by the WIDTH controls; the other pulse occurs after the delay time for a duration set by the WIDTH controls. In the DOUBLE PULSE mode, the spacing between the two pulses is determined by the DELAY setting, and the width of both pulses is determined by the WIDTH controls. In the DOUBLE PULSE mode, both the width and the delay should be at least 20nSec for proper operation.

2.2.10 NEG OUT
The .8V/1.5V toggle switch allows the selection of one of two forms of negative outputs. With the toggle switch at .8V, a fixed -0.8V pulse into 50 Ohm from a 0V base line is selected. This is the standard fast NIM logic.

With the toggle switch in the 1.5V position, ECL compatible logic levels into 50 Ohm are available. The base line is -0.5V, and the pulse top is - 1.5V.

2.2.11 POS OUT
The positive output connector and controls provide an adjustable positive output level with NORMAL or COMPLEMENTARY pulse oper- ation. An AMPLITUDE control allows the pulse top level to vary from +0.5V to +5V. The AMPLITUDE control is an attenuator that should operate into 50 Ohm in order to provide the 10:1 amplitude control.

A NORM/COMPL toggle switch provides either NORMAL or COMPLEMENTARY pulse operation. In the NORMAL pulse mode, the output pulse is at a high level for the duration of the pulse width and has a base line of about 0 V. In the COMPLEMENTARY mode, the pulse is near 0 V for the duration of the pulse width and at the adjustable high level at all other times. In the COMPLEMENTARY mode, duty factors larger than 90% can be obtained.