Hi,
I would like to reduce the sensitivity of a simple commercial night light so that it operates when there is a reduction of light below a threshold rather than onset of dusk. I am using the 'spare' electricity generated by our solar photovoltaic panels to heat water in our hot water cylinder using its electric immersion heater. I'm manually switching the heater on and off when at home according to what I perceive as the level of (sun)light. I know there are automatic ways of switching but I am happy at the moment to have a simpler method eg having a visual or audible warning of 'low' light level.
I have looked at the circuit of a low-cost nightlight and wondered whether the sensitivity could be easily reduced to achieve my requirements. I have seen the suggestion in a posting on these forums to put sunglasses material in front of a photodetector and if necessary I will try this but it seems a 'clunky' way of doing it.
I have included what I think is the circuit of the nightlight although I wouldn't guarrantee that I have got it completely right. The photodetector is a 2-lead device but doesn't look like the usual LDR. I did some electronics many years ago but am very 'rusty' so an explanation of the existing circuit would be helpful. Look forward to receiving your advice and comments.
Thanks
Peter
Market Harborough, UK
I would like to reduce the sensitivity of a simple commercial night light so that it operates when there is a reduction of light below a threshold rather than onset of dusk. I am using the 'spare' electricity generated by our solar photovoltaic panels to heat water in our hot water cylinder using its electric immersion heater. I'm manually switching the heater on and off when at home according to what I perceive as the level of (sun)light. I know there are automatic ways of switching but I am happy at the moment to have a simpler method eg having a visual or audible warning of 'low' light level.
I have looked at the circuit of a low-cost nightlight and wondered whether the sensitivity could be easily reduced to achieve my requirements. I have seen the suggestion in a posting on these forums to put sunglasses material in front of a photodetector and if necessary I will try this but it seems a 'clunky' way of doing it.
I have included what I think is the circuit of the nightlight although I wouldn't guarrantee that I have got it completely right. The photodetector is a 2-lead device but doesn't look like the usual LDR. I did some electronics many years ago but am very 'rusty' so an explanation of the existing circuit would be helpful. Look forward to receiving your advice and comments.
Thanks
Peter
Market Harborough, UK
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