Remove some leds

Probably - depending upon which ones that you remove and the current that they are now running on and the maximum current that they can run.

Easier would be to keep all the LED's and replace one of the resistors with a higher value one. That would reduce the current in the LED's and their brightness. Put a pot in place of one of the resistors and experiment.

Since the leds are in opposite ways round it assume it's run from an ac transformer (if all of them work). Just remove L4 and then only L1 and L2 will light and the resistors will be correct for that half of the power cycle.

I noticed that 1 resistor is for ac line. Does that reduce 120 v to around 3 v? Do i modify the other resistor? Any idea what the box like item is?

That's a smoke box.

Get a black Sharpie pen, and color over the LEDs that you don't like. That's what I did to fix some annoying LEDs in my car instrument panel.

Both resistors are in the AC line - one on each side. Don't know they'd use 2, unless it is a feeble attempt to isolate the LED's from the line. Yes, their purpose is to drop the voltage.

The box is in parallel to one of the resistors & I have no idea what it is.

a capacitor maybe? as an element to drop voltage. The resistor in parallel is to discharge the cap.

They are using capacitive reactance to limit current to the LEDs and they have each set of LEDs wired +/- so that a rectifier isn't required.

One pair conducts on the positive part of the sine wave and another pair on the negative.

The LEDs need each other. Reverse breakdown of LEDs is on the order of 5V or so. The conducting pair protect the non-conducting pair by limiting the voltage.

To ditch two of the LEDs you could put a rectifier diode (a 1N2004 would be a good choice) in place of them. The rectifier would be conducting and shunting the current limiting the voltage to ~0.6 V protecting the remaining LEDs. There'd be more flickering and you may find that annoying.

There's no transformer isolation so you'd get a nasty shock if you fool with it cover-off and plugged in.

I'm guessing that if you plug it in then remove it from the outlet and touch the prongs the led would come on for a short time as the cap discharged through your fingers.

Or you could just put some paint on the LEDs or mask them with tape.

The cap is dropping the voltage, the resistors are there as inrush current limiting and as fuses in case the cap shorts.

I've got a Fairchild opto electronics applications manual that shows the circuit. Capacitive reactance is a lot cheaper than a transformer or power supply and is very efficient.

They use the same thing in some consumer things like coffee machine digital timers.

If you want to use it yourself - the cap must be AC rated for voltage or a film type DC 3-4 X higher voltage. You use the formula for capacitive reactance to calculate the reactance at a particular frequency and it is expressed in ohms.

Another neat trick is to wire a cap across a light switch that controls LED bulbs. A point 5 microfarad cap will turn the LED into a night light when the switch is in the off position. (some require a little higher capacitance to light at all, but .5 is a good place to start.)

In my bedroom I have a three position switch on the wall so I can run the overhead light at reduced power when I'm searching for my clothes in the dark and don't want to wake my wife. In the living room it is across the standard light switch, and much better than the ordinary night lights because it is the overhead light and not behind some furniture like so many plug-in night lights. It only dissipated a watt in night light mode so it is still very efficient.

AND unlike lamp dimmers controlling LED lamps there's no flicker to speak of. (although there is a strobe effect with rotating things like fans)

I just went back and looked at the circuit again. R1 looks like it is across the cap so it discharges the cap when unplugged, so you wouldn't see it light by putting your fingers on the plug prongs.

I decided to paint 2 of the leds. :-)

Andy

You would have to short two of the LEDs. Black paint is easier.

The thing controlling the brighness is that big capacitor.

The easiest way to make that nightlight dimmer is to take a marker pen or some paint and darken the LEDs a bit.

Or since they are two series strings you could remove two from opposite corners and replace them with wire links.

Or add a resistor parallel with the LED string, (from the T shape to the C shape) about 330 ohms could be a good starting point.

Next easiest would be to replace the capacitor with one of lower capacitance, you need one that's X1 rated.

How about some black tape? or more permanent black goop.

George H.

I painted two of the leds.

Andy