Auto Day Night Off On LED Light Board price list

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A simple board use as Dusk to Dawn Light or Emergency Light 

12v operation Solar panels support up to 20w.

Sensitivity of the LDR can be adjusted via Preset. 

• Ultra Compact - PCB size just 9 cm x 4 cm.
• Battery Support - 12 Volts
• Transformer Required - 0 - 15 VAC 1 - 2 Amps ( for AC main operation )
• Solar panel - 12 volts 10 to 20 watts 
• Standard components - All components used are available online or at your local electronics store.  
• No SMD components used - Only through hole components used, making soldering and replacement hassle free.  
•  Cost effective - This amplifier can be made in a fraction of cost compared to similar amplifiers available in market. 

 Mains Power is applied via 0 - 15 volts transformer, it is rectified via D1,D2,D3,D4 Diodes and given to U1 voltage regulator.

The output voltage of U1 is set between 15.5 volts to 16.5 volts via RV1. 

12 volts Battery is charged by this constant voltage variable current through D5 and R4. 

when the Battery Voltage reaches 15volts, zener D6 turns on transistor Q1, cutting off U1 and stopping charging current.    

The LED's are Controlled by LDR, in light LDRs have low resistance so Q3 will not turn on.

 in Darkness LDRs have high resistance so Q3 will turn on the LED lights. 

Always keep the LDR in the Shadow of LED's. LDR sensitivity towards light / Darkness can be adjusted via RV2.