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The circuits for musical lights available in the market are highly expensive and based on microcontrollers. Also, their programPLQJ LV YeUy GLIfiFXOW. HeUe LV D VLPSOe and cheap circuit for a musical light that you can build easily.

The circuit presented here is of an eOeFWULF ODPS flDVKeU WKDW flDVKeV wLWK music. It uses ten S0W, O30V AC bulbs. 7KeVe EXOEV JOrw LQ DFFrUGDQFe wLWK the amplitude of the audio signal. The circuit is built around 5-dot dual LbD level meter driver IC hAOO81 (IC1), pnp transistor BC55T (T1 through T10), triac BT13S ( TRIAC1 through TRIAC10) and some discrete components.

7Ke ,C .A2281 KDV Wwr DXGLr LQ- puts. It is used in audio level indicators wLWK rSeUDWLQJ YrOWDJe UDQJLQJ IUrP 5V to 14V. Features include high input LPSeGDQFe wLWK exWeUQDOOy DGMXVWDEOe JDLQ rI LQSXW DPSOLfieU.

,W LV DQ DFWLYe-‘Orw’ ,C. WKeQ WKe amplitude of the input increases, the respective driver pins of IC hAOO81 go Orw. 7KeVe SLQV DUe FrQQeFWeG Wr WUDQVLVWrUV, wKLFK DFW DV VwLWFKeV DQG WXUQ on respective triacs. TRIAC1 through TRIAC10 are used to turn the bulbs (B1 WKUrXJK B10) ‘rQ’. ,QSXW Wr WKe FLUFXLW LV JLYeQ IUrP DQ DPSOLfieU.

7Ke wrUNLQJ rI WKe FLUFXLW LV simple. Connect the input from the DPSOLfieU Wr WKe FLUFXLW. AFFrUGLQJ Wr the amplitude of the audio signal, the rXWSXW SLQV rI ,C1 Jr Orw, WUDQVLVWrUV 71 WKUrXJK 710 FrQGXFW Wr fiUe TRIAC1 through TRIAC10 and respective EXOEV (B1 WKUrXJK B10) JOrw. BXOEV B1 WKUrXJK B10 WXUQ rQ wKeQ FrUUeVSrQGLQJ rXWSXW SLQV rI ,C1 Jr Orw.

All the emitters of transistor T1 through T10 are connected to the posiWLYe WeUPLQDO rI WKe SrweU VXSSOy DQG the collectors of transistors are conQeFWeG Wr WKe JDWeV rI WULDFV. 6r wKeQ pnp transistor T1 conducts, bulb B1 JOrwV. 6LPLODUOy, wKeQ 72 FrQGXFWV, EXOE B2 JOrwV DQG Vr rQ.

In brief, the bulbs (B1 through B10) JOrw GeSeQGLQJ rQ WKe DPSOLWXGe rI WKe PXVLF. CrQQeFW WKe SrweU VXSSOy line (L) of mains to bulbs (B1 through B10) and neutral (N) to MT1 terminals of TRIAC1 through TRIAC10.