Small Metronome Circuits Diagram

Small Metronome Circuits Diagram

Notes:

Q1 & Q2 provide linear frequency operation of IC1 following P1 resistance variation.
Q3 was added in order to obtain a louder click, similar to clockwork metronomes.
A 12V micro battery was used to obtain a higher output power and more compactness.
Rotate P1 fully towards R2, then set R1 to obtain 40 beats per minute (compare with another metronome).
Rotate P1 fully towards R3, then set R4 to obtain 208 beats per minute.
Finally mark the entire scale with the usual metronome steps, as follows:
40 - 42 - 44 - 46 - 48 - 50 - 52 - 54 - 58 - 60 - 63 - 66 - 69 - 72 - 76 - 80 - 84 - 88 - 92 - 96 - 100 - 104 - 108 - 112 - 116 - 120 - 126 - 132 - 138 - 144 - 152 - 160 - 168 - 176 - 184 - 192 - 200 - 208.

Parts:

P1______100K   Linear Potentiometer

R1_______10K   1/2W Trimmer Cermet

R2_______10K   1/4W Resistor

R3______330K   1/4W Resistor

R4_______50K   1/2W Trimmer Cermet

R5______100K   1/4W Resistor

R6,R7_____1K   1/4W Resistor

C1________1µF   63V Polyester Capacitor

C2_______10nF   63V Polyester Capacitor

C3_______47µF   25V Electrolytic Capacitor

IC1_____NE555   General purpose timer IC

Q1,Q2___BC560C  45V 100mA Low noise High gain PNP Transistors

Q3_____ZTX753  100V 2A PNP Transistor

SW1______SPST Switch (Ganged with P1)

SPK______8 Ohm 40mm. Loudspeaker

B1_____12V Battery (MN21, GP23A or VR22 type)

Comments

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