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µC generates musical sounds: 04/15/99 EDN-Design Ideas / (added 6/06) [Note:
File contains multiple circuits. Scroll to find this one] Many modern
devices send audible signals to IR operators to indicate some of predetermined
conditions or states of system under control. To avoid annoying human sensibilities,
se sounds should match musical scale. Several chips on market provide such sound
capabilities; for example, a programmable sound generator or an ISD1016 voice
massager. Circuit in Figure 1 does not use a dedicated sound generator but rar
generates sounds using software routines. Circuit uses an inexpensive
MC68H705J1A µC and saves additional expense by eliminating need for a sound chip. In
Figure 2a, a note represents pitch of each musical tone; Figure 2b shows duration of
tone.... |
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10 to one voltage divider for direct input: Very simple DI-box idea for your
guitar amp output... (circuit design added 10/06) |
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100 Watt Guitar Amplifier #2: (electronic circuit added 4/05) |
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100 Watt Guitar Amplifier Mk2: (circuit design added 3/05) |
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10W Audio Amplifier with Bass-boost: High Quality, very simple design No
need for a preamplifier (added 4/05) |
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25-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (circuit /
schematic design added 2/07) |
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300W Subwoofer Power Amplifier: Please note that specification for
this amp has been upgraded, and it is now recommended for continuous high power into 4
Ohms, but You will need to go to extremes with heatsink (fan cooling is highly
recommended). It was originally intended for "light" intermittent duty, suitable for
an equalized subwoofer system (for example using ELF principle see Project
Page for info on this circuit). Where continuous high power is required, anor 4
output transistors are recommended, wired in same way as Q9, Q10, Q11 and Q12,
and using 0.33 ohm emitter resistors. ... (added 4/05) |
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5 band graphic equalizer using a single IC/chip: This circuit uses a single
chip, IC BA3812L for realizing a 5 band graphic equalizer for use in hi-fi audio
systems. BA3812L is a five-point graphic equalizer that has all required
functions integrated onto one IC. IC is comprised of five tone control
circuits and input and output buffer amplifiers. BA3812L features low
distortion, low noise, and wide dynamic range, and is an ideal choice for Hi-Fi stereo
applications. It also has a wide operating voltage range (3.5V to 16V), which means
that it can be adapted for use with most types of stereo equipment.
five center frequencies are independently set using external capacitors, and as ….
(added 10/05) |
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60W Bass Amplifier: Low-cut and Bass controls. Output power: 40W on 8
Ohm and 60W on 4 Ohm loads (added 3/05) |
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60W Guitar Amplifier: Bass, Treble, Harmonic modifier and Brightness
controls. Output power: 40W on 8 Ohm and 60W on 4 Ohm loads (added 3/05) |
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8 Note Tune Player: Circuit plays 8 note tunes at any speed (added 5/02) |
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9-Pin PC Serial Port to MIDI Synthesizer Interface Cable: (circuit /
schematic design added 6/06) |
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Add harmony to your system: 07)/20/00 EDN-Design Ideas / (added11/05) Have
you ever wished you could distinguish one device's operating state from anor's by
sounds y make or that error states would sound harsh while normal operations would
sound harmonious? By combining NCO technique from a previous Design Idea
(Reference 1) with digital mixing, you can obtain musical chords or intervals with a
minimal amount of hardware and software. Any µC system can thus produce a variety of
sounds. In Figure 1, a piezoelectric speaker, Radio Shack Model 273-091, and two 270W
resistors transduce a pulse stream from a µC. Differential drive to this transducer
increases volume by doubling effective voltage. The capacitance of
piezoelectric speaker reacts with 270W resistors.... |
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Add music to your next project: 12/23/99 EDN-Design Ideas / (added 3/03)
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Apple Mac to MIDI synthesizer interface cable: (electronic circuit added
2/07) |
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Apple Macintosh MIDI interface schematic (basic version): (electronic
circuit added 2/07) |
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Apple Macintosh MIDI interface schematic (deluxe version): (diagram added
2/07) |