Frequency Central CHRONOGRAF, Build Documentation, Page: 2 / 5

Chronograf is a super flexible one-shot and cyclic event generator. It can be used as an
envelope generator, LFO, or master clock.
Chronograf features Start/Reset and Stop momentary switches, each with associated
control inputs, as well as a tap tempo momentary switch. A toggle switch selects between
one-shot and cyclic modes.
Four knobs are available to set Tempo, Waveform, Multiplier and Function. There is
another toggle switch to select whether changes to Multiplier happen immediately or at the
start of the next clock cycle.
Chronograf has 5 outputs:
•
LFO out
•
180 out (same as LFO out but 180° out of phase)
•
Clock out
•
Start cycle out (Clock divided by Multiplier)
•
Reset out (momentarily goes high whenever Start/Reset is pressed)
Waveform selection is chosen by a combination of Waveform and Function knobs. In this
way (arguably) 64 waveforms can be selected.
Bill of Materials
1K x 11
10K x 5
12K x 2
20K x 1
27K x 1
47K x 3
100K x 5
All resistors ¼ watt
metal film.
2n2 x 2
10nF x 3
100nF x 4
10uF x 1
47uF x 2 CHRONOGRAF PIC
TL084 x 4
TL072 x 1
BC547 x 2
1N4148 x 5
78L05 x 1
3mm red LED x 4
14 pin IC socket x 2
8 pin IC socket x 1
B100K x 4
10K trimmer x 1
3.5mm socket x 7
SPDT switch x 2
Tactile switch x 2
Momentary switch x
1
Male header x 1
(cut to size)
Female header x 1
(cut to size)
Power header x 1