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Adrian Caspersz Adrian Caspersz is offline
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Default Disconnecting CFL bulb from powered circuit can cause damage?

On 16/03/2019 01:54, Jeroni Paul wrote:
I have a mosquito trap with a circline 10W UV fluorescent bulb and a fan, the bulb went bad and it proved difficult to get a replacement. Now I would like to run the bulb only at night to extend its life and I tought to add an LDR, some transistors and a relay to run the bulb only at night.

Problem is the same inverter runs the bulb (CFL like circuit) and the fan, and the fan must never stop. The inverter has separate transformers for the bulb and fan but the drive circuit seems shared.

My concern is if I can place the relay in series with one of the four bulb wires to turn it on and off safely. The inverter ran for several months with a blown bulb so it has no problem to run without a load. But can it be damaged if the bulb is disconnected while powered?


How complex would you like this?

I'd separate things and run the fan from it's own power supply that also
supports a circuit that

1) switches the fan off after the lamp has cooled,
2) doesn't allow the inverter to turn on if the fan is not running

A bit of simple logic, or a micro....

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Adrian C