Mains driver wiring

I’m building a light with this

I see two AC IN solder points next to the fuse. I assume those are both for connecting positive - where to I connect ground?

I can't say I know (don't know much about AC) but I just would like to say be very careful with that. I personally would recommend just using a USB (5v) power supply to power a 7135 driver, which is what I have done in past.

I don’t think that would power these two emitters wired in series :wink:

True. ;) Also, if you feel like getting a bit more insane there is this 100 watt LED.

Either way, I'm looking forward to the results! :D

AC Doesn’t have a “Positive” and a “Negative” Like DC Does. Connect one wire of your AC to one AC~ Pad and the other wire to the other AC~ Pad. Doesn’t matter which goes where.


excellent, thanks

My pleasure.

If you are using a standard AC cord, the black wire is the “HOT” wire. white is the neutral, and green is the safety ground. Line and neutral are what supply the juice. If you get yourself between the hot wire and something connected to ground, you die… remember “black death”. Getting between neutral and ground can still be, uhhh, unpleasant. All this assumes that the idiot that wired your house got his colors right.

Black to Brass to Save Your Ass

it will be wired to a 2-prong extension cord

I got two of these awhile back, $10 each from newegg.

in stock form it is a joke - the huge “reflector” doesn’t do anything - there’s a tiny cup at the bottom and that’s the only thing light hits.

I’ve removed almost all of the back of the head housing to make room for a sizeable heatsink that I robbed off a dead amplifier. I also have two fans that will be mounted to the heatsink.

I use one of those tester thingies with the three neon lights in them. You plug it into each socket and check for the proper pattern of lights. When I bought my current house, around 10% of the outlets were screwed up. Also, they had a couple of lighting circuits with two dimmers on them… sweet!

Also, when dicking with power wiring I also double check the wires with one of those non-contact hot wire detectors before diving in.

Way more fun to use a craftsman screwdriver across the wires as a ’hot-wire-detector”:slight_smile:

None of those things surprise me… I’ve seen electricians that were flat out color blind. Works ok when you’re dealing with simple residential (White/Black) but start throwing three-phase power into the mix (Black/Red/Blue/White/Green) and it’s amazing more shit doesn’t burn down.

To the metal box that this circuitry will be enclosed in but the 60w rating is probably with free air flow around the heat sink and components.

Voltages with respect to ground are what you have to be concerned with, and the output voltage of this device with respect to ground is “undefined” but is probably not zero.

You don’t want to see my favorite reversible head screwdriver that I bought from Montgomery Wards when I was 12 years old… let’s just say that it’s been bit more than once.

ok, another question

the host has an omten 1.5A/250V clicky switch.

am I correct in assuming that it would be unsafe to switch the hot leg of the incoming AC with that?

It would be a real PITA to switch the driver output because I’d have to route the wire down through the host to the switch, then back up.

Maybe I’ll just skip a switch all together, or put one of these in the cord

I should be OK to use the clicky switch. All that lamp cord switch does is switch one of the AC wires (which one it switches is debatable). You do want to switch the hot lead. Also there is a fuse on the power inputs to that driver board… you want the hot (black) wire to go there.

A 1.5 A switch will probably not hold up because switch mode power supplies pull enormous current on start up to charge the input capacitor. It’s worse than switching a motor load or a tungsten load.

Maybe the supply maker can recommend a suitable switch.

funny you mention that.

I did a test yesterday, to be sure the power supply still works after potting, and it takes nearly a full second for the leds to turn on after the power supply is plugged in.

if you plug it in for ~1/2 second and unplug it, a ~1/2 second later the LEDs flash once lol

I’ll probably wire it up w/ stock switch and if it stops working I’ll put a higher capacity rocker switch there.

It might have soft-start circuit so then you’d be OK with almost any switch. If the mains go into a diode bridge and then to a capacitor or if your switch contacts weld shut or get vaporized there is probably not a soft-start.

if the switch welds on, I’ll probably just use the cord as the “on/off” lol

I’m relatively certain the light will be able to run indefinitely (ie, it won’t overheat), but we’ll have to see. Of course, if (or rather, when) one or both of the fans fail, it will eventually overheat.

the circuit had a small heatsink screwed to it. I took that off, then potted it (and screwed it) to the LED heatsink, but I don’t think it has any temperature protection…