Wiring Question - Rheostat and Rocker switch in series, lights are still on?
 

I am wiring a DIY LED fixture and my goal is to use rheostat(dimmable driver) and a rocker switch in series so that I can switch off the lights completely with the rocker switch and dim with the rheostat. The rheostat alone does not dim to zero hence the rocker switch.

When I put the rocker in the off position switches the LEDs do not completely extinguish, same as if the dimmer was turned to minimum.

Three post 25ohm rheostat and the rocker is the existing switch on the Biocube hood. How can I wire this please so I can completely turn off the lights without unplugging from the wall? Thank you.

are you using meanwell driver?

Yes.

a 5000 ohm resistor across the output of the driver will make the leds go out completely, you need a 10,000 ohm reostat to make the dimming work correctly

If you have the switch wired correctly to cut power either to the driver or to your LEDs, it should turn them off. You need to interrupt (cut) the positive lead completely & wire that through the switch. One could cut the negative but normally it's the positive that is switched. The switch will provide manual shut off only in this configuration. Another option would be to put the lights on a timer that turns them off completely when your photoperiod is done.

if you cut the power to the driver you will get a lightning flash.
are you using a dimmable driver?

Yes Dimmable. What is a lightning flash please?

if you cut power to driver, the driver will discharge its internal capacitors and the leds will give a bright flash like lightning.
the meanwell driver requires an external 10v power source for the dim circuit, normally u would use a 10k pot with a 10volt power supply to get your 0-10v for dimming, the drivers do not shut off completely but a 5k resistor across the led terminals will stop the glow and the leds will be off.

Not sure I fully understand this. I'm assuming using a mechanical switch properly wired would not be much different than when you unplug or plug in a meanwell driver? Would you not then get a lightning flash every time you unplug the driver? If so, then it's not a good design. You'd think they would have a 'bleed' circuit in the driver similar to more conventional ballasts to prevent capacitors from discharging into a connected load. Please explain further if possible. Have you witnessed this lightning flash in a circuit so configured?

I have 6 meanwell ELN-60-48D drivers running my leds, if I cut the AC power to the drivers I get a brief lightning show as the capacitors discharge, if I cut the DC power to the leds then no show.
I keep the AC power on all the time and use my RKE ALC to control the dimming but the leds don't completely go out (faint glow), however, installing a 5k resistor across the output terminals of the driver remedies this and the leds go completely out.

Interesting. Thanks for that. Do you suppose the lightning phenomenon harms the LEDs long/short term? Something to consider for folks planning to use this type of driver.

On both my DIY setups when the AC is cut the lights slowly fade out over 20 seconds or so, presumably as the capacitors discharge. No lightning effect.

I ended up not using the rocker switch in my original post. Thanks all.
Keith