Archive for October 5th, 2018
A discarded 20 W halogen desk lamp arrived in the Basement Laboratory for rebuilding:
An incandescent bulb doesn’t care about AC or DC, so a simple transformer also serves as a counterweight in the base:
I might replace it with some steel sheets, although I have no immediate need for a bare transformer.
A case adds 19¢ to each 10 W 300 mA LED driver:
Nice strain relief on those line-voltage wires, eh?
A simple test setup with three 3 W COB LED panels:
I clamped them to the aluminum sheet for heatsinking before I lit ’em up. The circles traced directly from the lamp’s hardware give some idea of the eventual layout.
I have more-intense LEDs, but spreading the light over a larger area should work better for the intended purpose. These are pleasant warm-white LEDs, too.
The fourth LED raised the forward voltage beyond the supply’s 42 V maximum, causing the supply to blink on and off.
Much to my surprise, the driver has plenty of 60 Hz ripple:
The top trace averages 280 mA and the bottom trace 32 V, so the LEDs run at 9 W = 3 W apiece, as they should.
Now, for some metalworking …