User manual

A&D Board User Manual and Test Procedure

The "up arrow" pulser starts at logic LOW (or 0) and becomes HIGH (or 1) only when the

button is pushed.

E) Digital Clock

The digital clock provides a square wave output with approximately 50% duty cycle. Its

frequency can be varied between about 60 Hz and 40 kHz, using the CLK FRQ knob. The

clock frequency increases when the knob is turned clockwise. The high state is typically 4.7V

and the low state is typically 0.3V. Any of the 4 holes of the CLK socket header may be used

to connect the digital clock to a circuit on the breadboard.

A bi-polar LED, located between the CLK and EXT CAP socket headers, indicates the logic

state. When this LED lights both red and green, the digital clock is operating normally. If the

output is stuck low, the LED will be green; when stuck high, the LED will be red.

The frequency range of the digital clock may be lowered by adding an external capacitor to

the EXT CAP socket header. Orient the external capacitor as illustrated by the symbol just to

the left of the header. You may use the top row, bottom row or both rows (for 2 external

capacitors in parallel).

F) Function Generator

The function generator outputs sine or square waveforms with adjustable frequency,

amplitude, and offset. The frequency can be adjusted from approximately 60 Hz to 20 kHz.

The amplitude can be as high as ± 7 volts, depending on the load impedance. The offset

control can be used to compensate for component and circuit variations.

Any of the 4 holes of the GEN socket header may be used to connect the function generator

to a circuit on the breadboard.

To select a square wave output, set the SHAPE switch to SQ. To select a sine wave output,

set the SHAPE switch to SIN.

The AMPLITUDE control adjusts the output voltage of the function generator. A clockwise

rotation increases the output voltage.

If the FINE FRQ control is turned fully counter-clockwise, the FREQ control adjusts the

output frequency between approximately 60 Hz and 5 kHz. A clockwise rotation increases

the frequency.

If the FREQ control is adjusted fully clockwise, the FINE FRQ control adjusts the output

between approximately 5 kHz and 20 kHz. If the FREQ control is set mid-range, the FINE

FRQ control can be used to make small adjustments to the output frequency.

The function generator has a small, non-linear DC offset, which is dependent on wave shape,

frequency, and amplitude. If the driven circuit is not sensitive to these variations, the

OFFSET SW can be set to OFF.

When the OFFSET SW is set to ON, the OFFSET control injects a DC bias. Turn the control

clockwise for a positive bias. This function is normally used to equalize the waveform

transitions above and below ground.

The bi-polar LED, just above the GEN header, indicates the relative output of the function

generator. When the OFFSET SW is ON, and the AMPLITUDE control is fully clockwise,

the OFFSET control can be rotated clockwise to produce a red-lit LED, or counter-clockwise

to produce green.