The circuit of automatic night lamp published early is little bit costly. But this circuit of automatic night lamp is perfect for hobbyists that it is uses very cheap components. It can be used as a bedroom light or a porch light. This night lamp circuit can connect directly to 230 V ac and surprisingly it doesn't use any eliminators or transformers so the cost will be further reduced.
We all know that a bulb need phase and neutral at its terminals to glow properly. So here we connect anyone of it direct to lamp and the other one connected through a triac. So lamp glows only when pulses available at triac gate. The pulses required for triac is made available by a diac through a LDR. So triac get its trigger only in night.
We all know that a bulb need phase and neutral at its terminals to glow properly. So here we connect anyone of it direct to lamp and the other one connected through a triac. So lamp glows only when pulses available at triac gate. The pulses required for triac is made available by a diac through a LDR. So triac get its trigger only in night.
Circuit Diagram of Automatic Low Cost Night Lamp : Click to enlarge
You need to assemble the circuit in a common PCB or a strip board and enclose it within a plastic case. Fit the holder of a bub to the case and connect directly to the socket. Note that you should adjust the RV1 preset to adjust the gate voltage of triac
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4 comments:
Great simple night light circuit.
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I have a 120 V source, what Resistors values do I need?
Resistor R1 is actually not required but it's included to protect the triac. Resistor R@ may 22K with same power.
what is the value of the diac ? can i use any any 100v 1A triac ?
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